To simplify the structure of decentralized automation systems it is necessary in the future to transmit the information and the power supply for the bus nodes over one and the same line. The paper gives a summery of existing serial bus systems with integrated power supply. The possibilities to use such systems in the sensor/actuator area is discussed and the physical and technical limits are shown. The conclusion is, that it is advantageous to adapt existing bus system of the sensor/actuator area by changing their physical layer. This can be done by several kinds of modulation as known in communication engineering.

CAN systems are designed to be used in automotive and automation environments where it is likely to have a high degree of electromagnetic interfer- ence disturbing the data transported between the transmitter and receiver. CAN uses several error detection mechanisms to prevent receivers from accepting disturbed data. Assuming a two-state symmetric binary channel model for the physical transmission medium, this paper analyzes the probability for errors to be undetectable at receivers (residual error probability). The contributions from different error mechanisms to the residual error probability are identified and quantified.

DeviceNet is an open network developed by Allen-Bradley based on CAN that is designed to allow low cost industrial control devices to communicate with each other. DeviceNet is defined in terms of an abstract object model which presents the suite of communication services available and describes the externally visible behavior of a DeviceNet node. The DeviceNet Model is application independent. DeviceNet provides the communication services needed by various types of applications. Many of today's lower level industrial control devices must retain their low cost/low resource characteristics even when directly connected to a network. DeviceNet takes this into consideration by defining a specific instance of the Model for communications typically seen in a Master/Slave application. This is referred to as the Predefined Master/Slave Connection Set. This paper describes the DeviceNet Communication Model and presents the Predefined Master/Slave Connection Set.

The trend towards distributed intelligence in automation applications is gathering pace. Many different bus systems are now emerging, aimed at the industrial automation market place. The Controller Area Network (CAN) offers several important features which can be exploited to give an optimum solution to many industrial applications. This paper presents some of the work carried out with CAN-based servodrives over the past few years. With thousands of drives in the field, the advantages of CAN have been clearly demonstrated and the features of CAN have been exploited in full. The multi-master capability is used to implement electronic cam and gear functions over the bus while the broadcast facility is used to synchronise the sample periods of all drives down to the micro-second level. Within the ESPRIT project ASPIC1, a device profile has been defined which details an open standard for addressing drives on a CAN network. This profile defines two channels of information over the bus, an operational channel for high speed, real-time data, and a service channel for parameter data. In designing the CAN Drive Profile, drive profiles for other bus systems were also taken into consideration.

DC motor control is the most distributed application in automotive body systems. As the number of DC motors in cars increases, a multiplexed architecture becomes the only viable solution, reducing cost and weight, improving reliability and control efficiency, and significantly increasing passenger convenience. This paper demonstrates in a practical example how products from National Semiconductor help minimize the cost of these applications, using CAN as the state of the art, fault tolerant networking solution.

Many time critical applications, e.g. measurement devices, require a real-time clock with an accuracy in the order of microseconds. In a centralised system this is easy to implement with standard timer devices, but in a distributed system (like a number of sensor and actor nodes connected via the CAN-bus) this is more difficult as there is no global system tick. This problem can be solved by synchronising the local clocks of all nodes with a sufficient accuracy. The tight timing guaranties of a CAN-network offer a simple and cheap possibility to provide such a global clock without additional hardware. The real-time group of GMDs CREW Project has designed and implemented a clock synchronisation protocol on the CAN-bus that provides a global time base with an accuracy of about 20 microseconds. The protocol is simple and hardware-independent. It uses only a small amount of bandwidth (< 20 messages/second) and works with a single, arbitrary CAN-object. If necessary, e.g. in large scale networks, the protocol can be synchronised with an external time-base, like a GPS satellite receiver.

The acceptance to use the Controller Area Network (CAN) in industrial automation systems has been grown noticeable in the last time. One reason surely is the short reaction time which goes back to the bus access method (CSMA/CA). The disadvantage of this bus access method is, however, that a defined reaction time only may be guarantied for the object with the highest priority. The question to be answered was, wether it is possible to realize message delay times and object cycle times which are acceptable for typical industrial automation systems. This also concerns the message time equidistance. Does the prioritized bus access conflict with the demands on message time equidistance? The investigations based on conditions of the sensor/actuator area in industrial automation systems. That means a transmission distance of a few hundred meters and a baudrate of 500 kBit/s.

A communication profile for real time systems which is based on the layer 7 specification CAN Application Layer (CAL) was developed in the ESPRIT pro- ject „ASPIC“. It supports the quick exchange of real time data as well as the utilisation of conventional device profiles. The concept involves the introduction of two communication channels with differing features: an operational channel for real time data and a service channel for parameter communication. Both are established between the cen- tral controller and the connected devices. The concept uses a subset of CAL. NMT and DBT are employed to perform network management and identifier dis- tribution whilst two CMS services are sufficient to accomplish the communica- tion channels. Device profiles interface to the communication profile. Here the communication objects are defined which enable standardised access to functions and fea- tures of the devices. The objects (e.g. parameter, modes or programs) can be addressed via an index in the service channel.

To wash aircraft’s a truck-based washing system was developed. The com- puter system is divided into two parts, An industrial robot control (IRC) and a bord computer. This bord computer is responsible for the diagnostic and con- trol of the system. A lot of signals must be analysed (about 250). To sample all these signals a CAN system is used. The advantage of this system is the distribution of connecting points and cabling. The safety of the whole system is higher than comparable systems with traditional wiring. The presentation describes the advantages, constraints, requirements and drawbacks for the implementation of CAN-system in the aircraft washing- system.

The CAN Protocol1 is currently implemented as on-chip peripherals integrated on microcontrollers and as stand-alone CAN chips. On-chip peripherals are available on several microcontroller architectures, including the MCS_ 51 and the MCS_ 96 microcontroller families. Likewise, there exists a variety of production-level stand-alone CAN chips such as the Philips PCA82C200 and the Intel 82527. The decision to use an integrated CAN peripheral or a stand-alone CAN chip should consider the tradeoffs between both alternatives. These tradeoffs include implementation cost, design flexibility, level of CPU burden and system reliability. This paper discusses these tradeoffs from both qualitative and quantitative perspectives. The goal of this paper is to identify the key issues that differentiate these two alternatives for various design and production goals.

CAN is known as a protocol for high performance and high reliable serial communication links between electronic control units in the field of automotive and industrial control applications. A new method of real-time support in the network allows to enhance the dynamic behaviour of the overall system as well as the diagnostic capability. With the microPD72005, NEC has developed a CAN controller, which allows to establish a global time system among the loosely coupled nodes of the network.

First the concept of the CAN-based in-vehicle network for the next generation of Mercedes-Benz trucks is introduced. This implies the connection of different systems, as e.g. engine- and braking-controller. A special characteristic of this information-network is the structure, where the components are combined in functional groups, which are connected via gateways, and organised in several hierarchical levels. Emphasis is put on concepts to the integration of external electric/electronic functions in the in-vehicle network. This will be shown on the interfaces to external systems such as bodyshell-electronics (e.g. concrete-mixer) and trailer-electronics (braking and non-braking applications), and on the data transmission via telephone ore satellite-communication for other services (e.g. vehicle pool management, emergency calls, remote-diagnosis and so on). The current position of this integration is illustrated by some examples. At the end of the discourse the question of standardisation is considered critically, and the consequences for the relationship in information exchange between car manufacturer, trailer and body manufacturer and suppliers for electronic systems are discussed.

A Controller Area Network (CAN) based communication protocol and control environment are presented for plant floor automation and control. This robust protocol allows for messaging between sensors, actuators, man-machine interfaces, controllers, and other plant floor control devices. This architecture provides a communications environment upon which a high-speed, real time centralized or distributed control platform can be created. In addition, the communication system provides the enabling technology for intelligent sensors, integration of advanced device diagnostics, and plant floor data-gathering, for communication to higher level networks. State of the art technology allows for the integration of the network interface into the smallest of plant floor devices. This system provides benefits in a variety of areas. Several real applications are discussed, including a description of an installation at a General Motors Engine Plant in Australia. A description of the benefits achieved in each installation is provided. In particular, machine uptime is improved through the integration of more intelligent devices such as programmable, re-configurable sensors with integrated diagnostics. Labor costs are reduced, due to the simplified interconnect system, and the easy addition to and modification of existing installations. Also, reliability is improved through diagnostics and reduced system complexity, and maintenance is improved through advanced tools for device and system configuration, monitoring, and troubleshooting. Reduced wiring costs can also be achieved, due to the bussing of devices.

The Society of Automotive Engineers’ Heavy Duty Truck and Bus Division created a committee to form a standard for multiplexed control busses in their vehicles. The architecture of these vehicles are complex in nature, comprised of several modules (cab, trailer1, trailer2, etc.). Therefore they chose CAN as the basis of their standard, specifically version 2.0B, for the 29 bit identifiers. Several documents were created that built upon the Bosch specifications but details all seven layers of the ISO/OSI (Open System Interconnect) model. This paper will show how and why certain implementations were used. Using 29 bit identifiers allowed segmentation of the identifier into content, source, destination address, etc. The physical layer is also specified it is similar to ISO 11898. The need for very fast transmission rates, typically under 20 milliseconds, forced the application layer to pack similar data inside one CAN message. The process of decoding these messages is difficult because in some cases one data parameter may affect how other parameters are decoded. Due to this, several tools have been created to help facilitate decoding of messages.

The smart sensor concept offers the benefit of a digital error compensation of non-ideal sensor characteristics and temperature influences. For this purpose, a dedicated correction processor was implemented which uses individual calibration data organized as a two- dimensional characteristic diagram to calculate the true measurement value. Sensor values up to 14 bit are supported. The characteristic diagram can be set up in an end-of-line calibration process using a serial EPROM data interface. The calculated sensor value is transmitted via a digital, bus-capable sensor interface which offers the possibility of interference-free signal transmission and supports future multi-sensor structures. In the presented implementation, this task is performed by a CAN protocol controller with a reduced message memory, thus leading to a minimized chip area. In the design process, the CAN protocol's reference environment, consisting of a protocol controller model, a testbench, waveforms and a simulator kernel was used to verify the implementation of the CAN interface. By describing the other parts of the chip including test patterns in the same high level language, the whole chip could be verified on functional level before breaking down the design to the schematic entry of the selected IC-CAD. Testvectors automatically generated by the functional model ensured the correctness of this transformation. The chip named CC400 was fabricated in a 1.2 micrometer CMOS process with EPROM option.

The CAN (Controller Area Network) is one of today’s most widely accepted car networking systems. Various protocol implementations are available from different suppliers. Dedicated protocol controllers - Full-CAN controllers - are found as system bus interfaces connected to a main CPU or integrated into them. Yet in some applications, particularly in the low speed arena, these devices don’t meet the price target or offer the flexibility required by the system designer. This paper outlines the application interfaces available for the CAN protocol, gives an overview to National Semiconductors CAN chips and it demonstrates in a practical example how these products can help to minimise the cost of Full-CAN controller applications while increasing the flexibility of such systems.

"Based on CAL, the Standard CAN Application Layer of the CiA, two general approaches for implementation of open networks which provide interoperability and interchangeability of devices are presented. In the first approach the application processes have direct access to the services and protocols of CAL. Application depended specifications are provided and additional standardized or nonstandardized ""Application Profiles"". With the second approach (""CANopen"") a standard application is specified which provides the environment for the usage of standard devices in different applications."

Since the number of available automation components with CAN interfaces is increasing more and more, there is a strong demand on interoperability between these components in multi vendor systems. However, the CAN in Automation community is still using a wide range of manufacturer specific communication solutions. In order to achieve interoperability of control components, communication and device profiles are to be employed together with the CAN communication layers that form the basis for specific implementations. CANopen, a set of existing and emerging profiles based on CAN Application Layer (CAL) is presented. These profiles are open to manufacturers and users. The CAL based Communication Profile For Industrial Applications (CiA standard DS 301) allows the definition of a wide range of device profiles e. g. for decentralised I/O, drives, vision systems, encoders, etc. The communication profile which is presented in detail provides fast event driven or cyclic messages as well as asynchronous data transfer. Since several companies have already adopted CANopen, an overview is given on ongoing implementations.

The DeviceNet Physical Layer and Media include the following features: CAN technology, multiple baud rates, cable distance up to 500 meters, Thick and Thin drop line or trunk line, drop lines as long as 6 meters, isolated and non–isolated physical layers, branching on drop lines and protection from wiring errors. In addition to providing CAN based communications, DeviceNet also provides power. Because power and signal conductors both are contained in the cable, devices can draw power directly from the network without the need for separate device power supplies. DeviceNet provides a flexible approach to supplying power along the bus. Both single and multiple supply configurations are supported allowing high current capability. Power supplies can be placed anywhere along the trunk line resulting in greater flexibility for the system designer. The DeviceNet power bus is supplied by one or more nominal 24 volt power sources and can support up to 8 amps on any section of Thick cable trunk line or up to 3 amps on any section of Thin cable trunk line. This paper describes DeviceNet’s physical layer, media and power capabilities.

CAN network protocol originally had been invented for automotive applications. Because of its characteristics, its robustness in conjunction with its excellent performance/price ratio CAN very soon was adopted for industrial control applications widely. The high sales quantities of more than 9 mio units until 1994 and the still more promising forecast illustrate the importance of CAN as a protocol in fieldbus and sensor/actuator bus applications. The following paper discusses the historical evolution of CAN until today, giving the reasons for the big success of CAN. In a second paragraph the technical characteristics of today’s CAN systems are analyzed and explained. Paragraph 3 dares a prognosis how and where CAN systems might go in the future.

DeviceNet connections can be configured with a multitude of behaviors based upon the transport class types and data production triggers desired by the end communicating applications. The DeviceNet communication model provides a variety of connection object transport class types and data production triggers. Connection objects can be configured to produce only or consume only. They can be configured to both produce and consume and to do so in a fashion that is either synchronous or asynchronous with the end application to which they are linked. DeviceNet connections are capable of producing their data based upon a connection timer (cyclically), upon a change-of-state of the I/O or at the application’s discretion. With this flexibility an end device may set up a myriad of communication links that are useful in architectures including Master/Slave, Peer- to-Peer and Distributed Control. This paper will present the communications links that can be established using DeviceNet connection objects and give examples as to how these communications links can be applied in the various network architectures.

This paper investigates the use of new alternative transport media for CAN, with specific focus on narrow band systems. Designing a physical layer for these kind of media implies using modulation techniques on a carrier wave. In an introductory study we give an overview of different digital modulation schemes and compare their performance. We identify the additional requirements imposed by CAN on the choice of modulation scheme and discuss some possible complications. As an application of the and results following from this study, we present a concrete design of a new narrow band physical layer for CAN, using the mains wiring as transport medium.

M3S stands for Multiple Master Multiple Slave and is a system concept designed to improve access to assistive technical devices by disabled people. It is a proposed standard architecture for general-purpose integrated and modular systems, which specification is available as an open standard. It is based on an industry-standard digital communication bus, the Controller Area Network (CAN), and includes additional signal lines to increase system safety and integrity. M3S provides a standard interface between input devices and end-effectors, allowing devices from different manufacturers to be linked in the same system. During revalidation phases this facilitates the process of evaluating different input devices and making the decision what input devices are optimal for a specific user. Furthermore the M3S architecture enables the user to operate more end- effectors, from categories like mobility, manipulation, environmental control and communication, using a single input-device.

The integrated transmission of information and power is a very important point of interest and a demand of many industrial bus system users. First results of such bus systems especially for simple binary sensors are known. The main task of our research activities is the integrated power transmission (IPT) in CAN systems even for analogue sensors with features of signal conditioning and data pre- processing. The paper presents a solution of such a bus node. Beside the conventional data processing a power management is necessary. In relation with the abilities of the node two methods of integrated transmission of information and power will be explained. The advantages and disadvantages for several application fields will be shown. Finally the results of the investigation of dynamic behaviour, error behaviour, and power capacity will be summarized.

The ever-increasing complexity of today’s electronic products creates a continuing demand for more sophisticated diagnostic systems, whilst the need for a simple user interface remains unchanged. A popular approach to system diagnostics involves the use of diagnostic fault trees. These can provide the product designer with a simple mechanism for the testing of operational parameters and a clear graphical display of the paths within the diagnostic sequence. This paper discusses the mechanisms that have been implemented to allow the use of fault- tree diagnostics on CAN bus systems. Also discussed are the additional capabilities that the diagnostic system can provide on the CAN network, and other ways of implementing diagnostic systems on existing software platforms.

The Controller Area Network (CAN) is a communication bus for message transaction in small-scale distributed environments. Continuity of service and bounded and known message delivery latency are requirements of a number of applications, which are not perfectly fulfilled by existing networks, CAN included. One key issue with this regard, is that networks are subject to failures, namely partitions. However, most of non-critical applications can live with temporary glitches in network operation, provided these temporary partitions are time-bounded. We call these periods of inaccessibility. Should one call for hard real-time behaviour, a worst-case figure for these non-negligible periods should be derived and added to the worst-case transmission delay expected in the absence of faults. This paper does an exhaustive study of CAN inaccessibility characteristics, presenting figures for intervals in CAN operation when the network does not provide service, allthough not being failed.

MCS-5 is a new, decentralized CAN-based automation system used mainly in ship automation. The system can be divided into two layers: monitoring and control, and process. This paper describes the function and the automation devices for each layer. The main points of the paper are the communication principles, protocol gateways and the use of PLCs within the system. The protocol layers and the communication services are explained. The paper also gives an overview of the PLC languages used. The trend to decentralized automation systems significantly influenced the development of the new MTU Monitoring and Control System, MCS-5. The new quality of this automation system is data processing within the decentralized automation devices and data exchange between them over field bus systems.

As today’s systems are becoming more and more complex, simulation is often the only viable way to verify the functionality of a system, or to estimate its performance. Especially in time and money critical sections it is important to gain information about a designed system before any expensive hardware is to be implemented. Using an object oriented simulation framework eases the solving of this problem. Different CAN components were developed separately and are now available as a CAN part library. Complete and heterogeneous systems can now be simulated and evaluated by taking parts from the library and connecting them using the standardized interface from the simulation framework. Configuration of the simulation is supported by a simple to use description language. The gained results are presented in the last section. We use the SAE scenario to show how the simulation results can be used to dimension a CAN network.

"We will describe a system, that uses CAN as a medium to connect different control devices on board of vehicles of the public transport system. Among the connected devices, tehre are main board computer, graphical display panels for teh information of the driver and a wireless data communication to a local traffic control center. Possible future extensions are the integration of a high speed infrared communication or measuring the position with a GPS receiver. We will give a technical overview on this system. Especially the implementation of an open system approach, based on the results of the CiA working group CAN in mobile applications will be described. There will be also a discussion of the advantages using an open approach, and possible reasons why not using an open approach. The authors are involved in industrial projects concerning these topics. They are also active members of the CiA working group: ""CAN in mobile applications""."

A distributed real-time computer system consists of several processing nodes interconnected by commlunication channels. In a safety critical application, the real-time system should maintain timely dependable services despite component failures or enfironmental changes such as transient overloads. In this paper the imprecise computation technique is integrated with fault tolerance schemes and adopted as the Adaptable Management System (AMS) which adjusts the operating strategy of the real-time system in response to changing application environments and the internal fault patterns. The timing response performance of the AMS for a Controller Area Network (CAN) based distributed real-time system is evaluated as to whether the timing constraints is satisfied for normal, overload, and degraded operational modes. The simulation study employs the Society of Automotive Engineers (SAE) real-time control system benchmark as the workload model. The simulation results also show that the quality of service of the AMS can be improved by varying the optional message in the workload.

CAN is well-suited to distributed real-time control of electric passenger vehicles. This paper describes the use of CAN to provide a tightly-coupled dual drive system, with real-time control distributed over the two drives. In order to achieve this reliably, the application layer has been extended. In order to maintain the integrity of periodic variables a Promptness feature using producer-consumer semantics is available as well as time-out mechanisms on inter-application events. Furthermore, a Global Data philosophy has been adapted where all data shared between the applications are tagged with a unique ID. This has many benefits as well as making it easy to monitor the overall system state via a Bus Analyser. The above approach can be used in and extended to a wide variety of performance-critical advanced vehicle applications.

The design of a CAN based system can be a complex task. Several issues need to be addressed: choosing the right modules, verifying that the chosen modules really are able to communicate, assignment of bus identifiers, verifying that the real time requirements of the system are met, selecting correct bus parameters, and so on. Kingdom Founder is a graphical design tool which aids the system designer in this process. Fetched from a database or defined on the fly, the modules and the CAN bus are drawn on a worksheet. The information structure of the system, as well as several module and system parameters are then defined. The system designer can then use the program to check for errors or potential problem sources, produce documentation and generate system startup information and code skeletons for the modules.

In this paper, we describe the hardware and software architecture of an autonomous mobile robot. ROMAIN, INstrumented Autonomous Mobile RObot, is an experimental platform dedicated to a wide range of applications. Its main characteristics are flexibility, high speed velocity, energetic and decisional autonomy and real time processing. This mobile robot owns an open structure based around a Control Area Network for data transmission between microcontroller cards and a real time operating system. After the description of this structure we propose an application consisting in the tracking of an other robot in an unknown environment with ultrasonic sensors.

During the development of the DeviceNet Specification, it became apparent that it would be necessary to provide a mechanism for common user friendly configuration of all DeviceNet products. It would have to be robust enough to cover a wide range of products, from the very simple, to the very complex. It would be required to be used by arbitrary configuration tools and be independent of the implementation of these tools. The configuration mechanisms would also have to be easy to implement in order to facilitate its adoption by product developers. It would also have to be cost effective to implement so as not to add excessive cost to inexpensive devices. This paper describes how the Electronic Data Sheet achieves these goals.

DeviceNet has emerged as one of the low level fieldbusses optimised for industrial control. It uses the robust and powerful CAN (Controller Area Network) technology as the backbone. Interoperability between various DeviceNet devices, advanced failure prevention and fault diagnosis, and lower implementation costs are some of the immediate advantages of DeviceNet. Interoperability brings the issue of compatibility and conformance among the DeviceNet devices from various vendors. This paper describes the issues involved in implementing a DeviceNet system both from developers' and end-users' point-of-views. It investigates the 'plug-and-play' and interoperability of DeviceNet devices. A study for realising a fully automated compliance test for DeviceNet is done.

The development of distributed architectures that rely on communication protocols for data exchanges between remote ECUs produced by different equipment manufacturers, sets new problems for car manufacturers who have the responsibility of the whole system. At each communication level, the car manufacturers have to be sure that the protocol implementations are compliant with the chosen standard. The CAN standard is a Data Link Layer protocol generally implemented in ASICs. So, there is a need for tools verifying during the design process that all the components produced, today and in the future, by a lot of different silicon suppliers, are and will be compliant with the CAN standard.

The Controller Area Network (CAN) is a serial bus with high speed, high reliability, and low cost for distributed real time control applications in both the car and the industrial environments. In an industrial environment, while the CAN is used by manufacturing sections to control the systems, the management department can use Ethernet (or Token Ring) LAN in its building. This implies that the CAN should communicate with a LAN. A solution is to use the internetworking devices to connect a CAN and a LAN. Bridges are high performance devices that are used to interconnect two similar or dissimilar LANs. The aim of this study is to design and implement a bridge which is capable of connecting a CAN and an Ethernet LAN. In the following, a brief overview about the CAN, the Ethernet, and bridges is presented. The required processes are detailed and the implementation of the bridge is explained in section 2 and 3, respectively. In section 4, the modelling environment for simulation is summarized. Finally, the results obtained from simulation are presented in section 5, and the conclusion is given in section 6.

Honeywell has been a long-term participant in the industrial control marketplace. Participation in this market has kept Honeywell in constant communication with customers concerning issues and needs in the marketplace. Over the past five to seven years, several key trends have driven requirements for change in control system architectures. One of these trends is increased levels of automation and decreased levels of available human resources. A second trend is decreasing product and technology life-cycles which have made fixed automation systems cost prohibitive. These trends have driven automation users to require systems that can be modified, adapted, or upgraded as required to sustain a long-term competitive position. Control systems must advance to provide information to assist users in the maintenance of complex automation systems. These market trends provided the force to encourage Honeywell to develop the Smart Distributed System. The Smart Distributed System is a device level network which is designed as a control platform for use in a wide variety of industrial machine control applications. Honeywell has now expanded the scope of the Smart Distributed System to include Personal Computer (PC) hardware and software to execute real-time control and provide Operator Interface software. The PC Control platform provides a mechanism that is well suited to take full advantage of information available from the networked Input/Output (I/O) system.

Since CANopen communication and device profiles are available the influence of this CAN communication standard is increasing thoughout the CAN in automation arena. Various CANopen-based components as well as OEM protocol implemenations are available. This contribution concentrates on experience drawn from software implementations on different devices and set up of CANopen networks. The software structure of network master and slave devices is presented in detail together with realisation hints. Achieved performance in terms of code execution time and consumption of hardware resources are described. The configuration of CaNopen devices and set-up of complete networks by the user forms the second section. Tools are presented which allow the access to object dictionaries of devices via electronic data sheet and parameter up- and download. Graphical user interfaces allow the layout of CANopen networks, support the distribution of identifiers and the cooperation of bus nodes. Finally, an application example in form of a multi-vendor system with several controllers, decentralized Input/Output devices and multiple drives is given.

The multiplexing systems currently being implemented are essentially information sharing systems. In the body system in particular, it is possible to reduce the cost of implementing features by growing one of the micros into a 16 bit device and slimming down the others. The bus will carry commands from the 16 bit master device as well as information. Many of the tasks in the body system do not need to run often. The 16 bit device can make use of large (economical) flash memory for reprogrammability, but in order to benefit from reprogrammability, the whole bus needs to run under a communications manager that will guarantee the real time performance of the bus when program updates occur. This type of development will further divorce electronics hardware from software, and will require organisational changes in companies to implement it effectively.

The paper gives an overview over the object-oriented methodologies including related workbenches, which were developed especially for modelling of distributed reactive systems. The applicability of this tools will be discussed with a concrete motion control application based on CAN . Also some aspects of hardware/software co-design of such kind of systems regarding to the quality and efficiency of the development process will be part of the presentation.

Machine control software are in general highly embedded in target systems. Distributed processors and standard CAN-buses have provided suitable tools to design machine diagnosis and fault tolerance based on user requirements or safety aspects. In this paper some general and on target machine designed diagnosing elements and monitoring functions are explained. The surveyd target machine is just developed for loading explosive into holes in mining applications. Because of highly dangerous work environment machine fault detection and diagnostic maintenance are of crucial importance. Both continuous operation and rapid responses are peculiar to the developed machine. On the basis of real time maintenance the error sources are divided in critical requiring immediate user operations and in slowly developing faults caused mainly by component wearing. The distributed computer architecture provides means to implement fault tolerating systems and especially CAN contollers facilitate to embed diagnosis messages both in measuring data and in special safety functions. The distributed control makes it possible to diagnose the functions of the machine more effectively, but, however, on the other hand the distributed control is a new and a serious risk factor. Without sufficient checking intelligent subsystems may behave unexpectedly: erroneous interpretation of system state or fault sensor can trigger the actuator on at wrong time with dangerous consequences.

This paper describes the introduction of new concepts into a tin can manufacturing line and its re-engineering with the aim of doubling the production speed. The design of the hardware and control system played an important part in matching the dynamics of the machinery to the production processes, and also in reducing costs and improving reliability.

This paper gives a survey on the historical background of CAN. Additionally, the paper handles different CAN controller implementations and discusses the use of CAN in automotive systems and in automation, including initiatives for open systems in both areas. Although originally developed for in-vehicle purposes, automation area started to apply CAN as soon as the first components became available. Since the introduction of the first CAN chips the sale of CAN components has been remarkably higher in automation than in automotive sector. However, the roles are supposed to change soon due to the growing use of CAN in automotive electronics.

Electronic control units (ECUs) linked together within an automotive network are generally supplied by different companies, and mostly include different micro-controllers and software architectures. Moreover, applications provided by different suppliers have to co-exist in a single processor in the future. Today's individual development processes for distributed, communicating ECUs hinder the integration of automotive systems and increase the overall costs. In order to achieve a significant reduction of these costs, services and protocols for communication, network management, and operating system must be standardised. The OSEK/VDX group worked out a respective specification in coperation with several car manufactuerers and suppliers. The specification will permit a cost-effective system integration and support the portation of system functions between different electronic control units. This paper gives a brief summary of the OSEK/VDX results and an outlook on the continuation of the project.

"""Objectmodul"" is not just another layer 7 for CAN networks. It is a universal SW Interface best fitting in distributed real-time systems and decouples the application from the different ways of transporting data. So the application can be developed independent of the layers (CAL, Devicenet, SDS, CAN Kingdom, ...) of the network (CAN, RS232, Dual port Memory, ...). The existing ""Objectmodul"" is implemented as a standalone SW module, but it is also possible to integrate it as an extension of an operating system. By using the ""Objectmodul"", the applications on various CAN nodes do not need any knowledge about the topology. This means, no knowledge is needed about the I/O is local or distributed by the network. The application just reads or writes objects and the ""Objectmodul"" controls the handling of the data. So the application program is completely independent of the way the data is transferred, the type of communication partner or data layout."

This paper discusses the design and performance requirements for the interconnection of wireless nodes to a standard CAN bus environment. It is focused on the network architecture as a single centralised cell consisting of a central node and wireless terminals. The central node provides data communication between the CAN and the wireless network. It maintains a self-learning algorithm for the frame filtering and forwarding requirements. The Medium Access Control Protocol used for the wireless network is specifically designed for supporting prioritised frame transmission in the wireless channel. The prioritisation is accomplished by using different sequence numbers which are added to each individual frame based on the CAN identifier. The performance of the system is analysed and presented in terms of probability, delay and channel utilisation under various traffic conditions.

A chip set for highly dynamic servodrives has been developed. Ist first application is a very compact, intelligent, CAN-controlled brushless AC servodrive. It can, however, be used for DC, brushless DC and induction servodrives as well. Main tasks of the chips are the calculation of rotor position, torque and current control as well as pulse-width modulation. The chip set not only enables the construction of economic and intelligent servodrives with high dynamics but, in addition, it considerably improves the reliability of the drives by drastic reduction of the component count.

As in other branches a central automation concept is the state of the art in industrial fluidic systems. When one wishes an open communication with CAN the problem arises to choose between several major Higher Layer Standards, such as CAL, CANKingdom, DeviceNet or SDS. In order to make open communication more efficient the idea is to have a Higher Layer independent API for fluidic applications (profile). Due to several Higher Layer Standards for CAN it is advantageous to divide such an API into a Higher Layer determined part and an application determined part. A proposal will be given in the presentation. We will show, that an open communication which fits the needs of fluidic systems causes a change of its automation structure. It is determined by decentralized devices with processing capabilities (e.g. device configuration and self diagnosis) which can fit to a special application by IEC 1131 compliant configuration facilities.

In recent years systems of CAN-connected automotive control units have been increasing rapidly both in complexity and size. Therefore not only functional but also performance aspects must be considered during development. For the system to be feasible, all communication timing constraints for all functions have to be proven. This feasibility has to be assured in early design stages already. This paper presents simulation results of a bus model as a basis for performance analysis of automotive CAN systems. The single server queue with non-preemtive priorities was chosen as a simple model of the bus. Each priority class represents a message of a certain identifier. Bus arbitration is implicitly modelled by the non-preemtive priorities of the service discipline. The simulation model considers not only cyclic messages (messages with constant interarrival times) but also sporadic traffic sources. Those sources emit only when their corresponding function is active. The obtained simulation results give the mean waiting time for the different priorities and can be used to tell if the system with the planned communication load can work acceptably for all realized functions. If necessary the design can be changed in an early stage to improve network performance.

MiniCAN is a concept that combines CAN compatibility with simplified functionality. It is optimised to attach basic components directly to a CAN bus. Those components are e.g. switches, lamps or sensors and actuators that do not require more than 6 bits of data. It is a master-slave system that uses an inframe response within the CAN data field to run a simplified protocol. Special concern was taken for security, low cost and ease of use. It may be used both for low and high speed communication, compliant to CAN specification 2.0, parts A and B.

Designers of soft real-time systems often ignore worst-case behavior analysis when designing their systems. We have developed a discrete-event model of Controller Area Network (CAN) to assess performance under both worst-case and normal conditions. The analysis revealed that many network events and attributes can lead to message serialization, which causes large network delays typical of worst-case behavior. This transient network behavior has serious implications on the application performance. In this paper, we present these results and show how the actual performance of the system varies over time between the normal and worst-case scenarios.

This paper deals with the analysis of real time systems subject to the time delay in the communication networks. Different approaches to handle the effect of communication delays are discussed. To improve the robustness of the control system, a fuzzy controller is used. The use of the fuzy technique is motivated by the fact that time delays give rise to phase lag, which often degenerate system stability and performances. The case of the Controller Area Network bus is particularly discussed.

"""In this paper we study the wireless communication extension for the Controller Area Network (CAN) protocol to suit industrial applications. Two different network topologies and medium access methods have been considered. The remote frame and the prioritised frame medium access control (MAC) methods are proposed for the centralised and distributed wireless CAN based network. The performance of these protocols is evaluated by simulating the protocols in the wireless CAN network. The “SAE Benchmark"""" is used as the workload to illustrate the industrial applications of CAN based system. This paper discusses the applicability of the proposed wireless MAC protocols and confirms its usefulness for real-time communication base on the benchmark."""

This paper will discuss the effect that the requirement for Antilock Braking Systems (ABS) is having on the trailer electrical system. The trailer’s electrical system will require an update and multiplexing is one of the possible solutions being considered by the industry. Vehicle multiplexing and the need for a prototype system will be discussed. Finally, the selection of DeviceNet and the advantages it provided us, along with, a description of the prototype system and how it was demonstrated as a sales and engineering tool will be given.

Due to conceptional reasons car manufacturers now implement not only one, but two (and even more!) CAN networks within each car. Such network structures require a transfer of data between the networks. This paper gives a brief introduction how such operations can be supported by special microcontroller modules. As transfer mechanisms for data between the CAN network subsystems are not well established yet, but under deep and controversial discussion, the aim of this paper is not to give a detailed technical description of the discussed solutions. It tries to describe general aspects and strategies for such transfers.

System Optimization, Diagnosis and Maintenance are becoming more and more important for improving the performance of CAN Bus systems. Therefore, modern CAN Controller architectures have to provide special functions supporting these requirements. This paper describes how dedicated features of a new CAN Controller can be used for this purpose. These functions also support an interesting approach for ”Plug & Play” solutions with future CAN systems.

"CAN today is the most widespread serial communication protocol in automative applications. Coming from the high speed, high performance applications like motor management, where CAN is fairly well established in almost all major car makers around the globe, it has now conquered the wide field of comfort and convenience electronics as well as driver information systems. Although numerous silicon manufactuerers have introduced a wide range of integrated microcontrollers with on-chip CAN, there was still lack of Application Specific Standard Products (ASSP) with CAN. NEC, an early pioneer of CAN activities, has established a complete new family of highly integrated microcontrollers specifically for the area of automotive instrumentation clusters. The new ""Direct storage CAN"" (DCAN) module of NEC ideally combines a CAN 2.0b extended frame compliant with ""Full"" CAN functionality at ""Basic"" CAN cost. The integration of highly competetive and application specific peripherals on NEC's powerful 78K/0 family in combination with Flash memory technology offers new perspectives and opportunities for system solutions at excellent price performance ratio."

"""Project Planning and Device Configuration in CANopen Networks In project planning for larger distributed systems there are a number of tasks that are time consuming, unclear and susceptible to errors. For CANopen systems and other networked facilities, these tasks include: • Analysis and structuring of all automation tasks, development of func- tional groups • Selection of the required network devices • Definition of the process data • Definition of the communication parameters • Establishing device parameters / application objects • Programming and integration of control units (PLC, IPC, ..) • Configuration download, start-up • System analysis • Documentation • Customer service This paper gives an overview of these important project tasks and details some selected topics. One specific part is the discussion of requirements to CANopen from the view of programmable devices such as PLC or IPC. Re- garding this, the paper presents a brief overview about parts of the work of the SIG Programmable Devices."""

Siemens are one of the largest forces within the European semiconductor market arena, with more than ten years experience in designing and manufacturing microcontrollers. Siemens' technology strategy for the embedded market is to develop tailored microcontroller architectures rather than modifying general purpose processors for embedded control applications. This includes optimizing the right cores for a variety of application segments, as well as developing various memory technologies and application-oriented peripherals such as CAN 2.0B. On these bases, Siemens has evolved into a world wide player particularly in the automotive, data-processing and telecom markets including localized support and decision making. In addition, specific derivative controllers have a strong stand in wireless terminals and smartcards.

The Institute of Control and Automation of the Technical University of Braunschweig develops a high efficiency container terminal for the entraining and entrucking of containers from train to truck and vice versa. In this container terminal a distributed information system consisting of some processors, sensors, actuators, communication systems (represented by CAN) and memories is embedded. By influencing the distribution of the tasks to the information ressources the specified hard real-time constraints have to be fulfilled. The new computation approach of balance equations for the integrated information system leads to the selection of an optimal task distribution strategy. Using simulation models of the container terminal, the field bus system CAN and the information system computer experiments are performed, analyzing the real-time behavior of CAN.

"""The primary focus within the standards organization during the first two years of existence has been traditional control system configurations consisting of a single client (master) and up to sixty three (63) servers (slaves) on a single subnet. There are numerous reasons for this focus, much of which is related to the initial content of the specifications, the availability of product, the learning curve of member companies, and so forth. Open systems require a concise definition of interfaces and behaviors, all of which may not be reflected within even the best of specifications. Providing concise and sufficient levels of detail has been one of the primary goals of the standards organization. Additionally, Special Interest Groups (SIGs) have focused on defining and refining additional application objects for various types of devices. These include simple I/O points, various sensors, actuators and even specialized subsystems like motion control. A goal of many of the participating vendors is an “Open Control System”, whose major beneficiary is the end user and system integrator. A small vendor may develop niche market products which may be configured and diagnosed using other vendors’ tools."""

Smart microsystems reduce the amount of data in field bus systems. A main part of such systems is the Multi Sensor ASIC developed by the Fraunhofer-Institute of Microelectronic Circuits and Systems (FhG-IMS) in Dresden. This ASIC links sensors to a CAN field bus and carries out signal processing tasks. By means of a modular design style on the systems level a good flexibility could be achieved. With its variety of interfaces this ASIC can be applied widely.

By building a system with an open device-level network, the system designer has the option to choose devices from different manufactuerers. To minimize the risk that devices will not interoperate correctly in such multi-vendor applications, individual devices need to be tested. This testing must be economical and assure a high confidence level. Therefore, the industry needs a test concept that allows for clear definition and development of the necessary test sets for individual devices. This document introduces a concept that separates conformance, interoperability, and integrity issues. With this concept and the international Standards Organization (ISO) Open Systems Interface (OSI) 7 Layer Model, the required tests can be developed and performed. This testing concept and its different test strategies are based on Honeywell's Smart Distributed System Test Verification Procedure, which also is explained and discussed.

Motion Control applications need fast and reliable communications to guarantee synchronized operation. CANopen provides the standardised protocol for CAN based controllers to build up heterogeneous networks of PLC's and motion controllers. The distribution of function blocks within a multi-vendor network of co-operating controllers requires a standardisation of programming languages. IEC 1131-3 established a mature standard in the market since some years. This paper reports work in PLCopen defining a set of standard function blocks and the corresponding software tools for portable motion control applications. Programs written for smart CAN devices use either graphical or textual languages. Ladder of Function block Diagrams Strucured Text or Instruction List. This report demonstrates that PLCopen Portability Level specifications for IL enable even the portability of motion control function blocks. It is the prerequisite for reusing software in control automation.

With a typical CANopen module already having a processor, RAM and ROM to serve the network, the next evolutionary step is to add user-programmability to these nodes. The now well established, vendor-independent standard IEC1131 should be the logical choice. This article will explain how a CCANopen bus is seen by IEC1131, and what the implication for CANopen is, and what the incompatibilites are. Then we will have a look at how CANopen and IEC1131 could be integrated, first at the tool side, then at the controller side. The last paragraph will outline how applications could use the combination of both standards.

Controller Area Network (CAN) technology has become increasingly more popular for factory floor applications due to its small size, low cost and high speed. This technology utilizes a clever bit-wise arbitration scheme for medium access control resulting in the non-destructive transmission of the highest CAN identifier. Although this scheme provides high throughput, it places a distance limitation on node separation since nodes must all respond within a fraction of a bit-time. For factory floor applications, this distance constraint could be a problem. This paper discusses the use of remote bridges interconnected with a high-speed deterministic network. Each bridge has two ports—one for a CAN segment and the other for the high-speed deterministic network. Messages received on the CAN segment are encapsulated into the data frame of the high- speed deterministic network and sent to all other bridges. Each bridge extracts the data and converts the data back to a CAN format for rebroadcast to all other CAN segments. Bridges can be separated up to four miles and can be cabled with either coaxial or fiber optic cable. These bridges operate at the data link layer and, therefore, all higher layer protocols such as DeviceNet, Smart Distributed System, CAL, CAN Kingdom and CANopen pass without modification making bridging applicable to several commercial systems.

We have developed optical CAN repeaters that connect two electrical buses with a pair of optical fibers. The repeater has a circuit that propagates the states of one bus to the other through the optical fibers and vice versa. Since a pair of repeaters can equalize the states of the two buses within a single bit time, the CAN network maintains real-time communication. Because of the translation overhead between electrical and optical signals, the transfer distance is shorter compared to that of an electrical CAN network at the same transfer rate. However, the CAN network maintains compatibility with the electrical CAN network. Further, the optical fibers can isolate the CAN network from noise due to high voltage lines and lightning surges.

In recent years distributed systems using the CAN bus have been increasing in both size and complexity. In order to meet system requirements, the impact of communication on the overall system must be understood early in the design cycle. Several approaches have been used to address questions like response time at different bus loads, functional partitioning, etc. However, most approaches neglect real life conditions like execution time, transmission errors or component damage. This paper presents a modelling strategy to simulate CAN based systems under real life conditions. We present a high performance CAN protocol model working on message level but providing bit level accurate functionality and timing. The presented methodology allows to analyze the reliability performance and overall behavior of CAN systems under real life conditions. Results can be used early in the system design cycle to make a tradeoff analysis, reparition functionality, refine alogrithms and to optimize the network configuration.

CAN networks are becoming one of the most used industrial local area network in many applications. Philips Semiconductors has been one of the manufacturers devoted to offer stand alone CAN controllers to make possible the connection to this network. The PCA82C200 has been used in multitude of CAN based microcontroller systems. At present, this circuit has been replaced by the SJA1000. This new controller offers new interesting features. An analysis of this new CAN controller, and its comparison with its antecedent is done in this paper. We use different methods as simulation languages and queuing networks, in order to obtain the main performance parameters of these controllers.

By building a system with an open device-level network, the system designer has the option to choose devices from different manufactuerers. To minimize the risk that devices will not interoperate correctly in such multi-vendor applications, individual devices need to be tested. This testing must be economical and assure a high confidence level. Therefore, the industry needs a test concept that allows for clear definition and development of the necessary test sets for individual devices. This document introduces a conecept that separates conformance, interoperability, and integrity issues. With this concept and the International Standards organization (ISO) Open Systems Interface (OSI) 7 Layer Mode, the required tests can be developed and performed. This testing concept and its different test strategies are based on Honeywell's Smart Distributed System Test Verification Procedure, which also is explained and discussed.

"Shortly after availability, the CANopen standard for industria automation became widely accepted within a wide range of applications. With the newest extensions of the standard, also IEC-1131 programmable devices in distributed, intelligent automation systems are supported. When merging CANopen into IEC 1131-based PLCs, facilities have to be provided for downloading and controlling of programs and tasks and for the dynamic mapping of PLC network variables into the CANopen Object Dictionary of the controller device. For program debugging via the CAN bus also an appropriate debugging chanel has to be provided. Furthermore, there are specific CANopen functions like network, configuration and SDO management which have to be accessible and controllable from the PLC kernel. In the paper, the main results of the CiA special interest groups ""Framework for programmable CANopen Devices"" and ""CANopen Interface Profile for IEC 1131-3 Environments"" will be summarized and the basic principle for the implementation of a IEC 1131-3 programmable CANopen-based PLCs will be described. Also, an integrated CANopen system configuration and programming tool will be presented shortly."

Due to conceptional reasons car manufacturers now implement not only one, but two (and even more!) CAN networks within each car. Such network structures require a trans- fer of data between the networks. This paper gives a brief introduction how such opera- tions can be supported by special microcontroller modules. As transfer mechanisms for data between the CAN network subsystems are not well es- tablished yet, but under deep and controversial discussion, the aim of this paper is not to give a detailed technical description of the discussed solutions. It tries to describe general aspects and strategies for such transfers.

Code for embedded systems is usually developed on a host system and then downloaded to the target. Several solutions exist to do this; most of them require plugging some hardware on the target system and connecting it to the host. Although adequate for mono-processor systems, they become awkward for distributed systems, mainly for two reasons. Firstly, several targets are required to be connected simultaneously to a single host. Secondly, targets may not be physically close to the host. One solution is to use the existing network to provide communication between host and targets. We have developed a system based on this solution over a CAN network. The stations are able to receive the code, store it and start execution, one of the stations being the gateway to the host. Our system allows the user to control the whole distributed system, downloading code to any of the stations and starting and stopping its execution. This is provided at low cost, with no additional hardware required.

The availability of the Layer 7 Communications CANopen, DeviceNet and SDS has opened opportunities for increasingly complex applications in the CAN application area. At the same time, the applications are expected to be executable for multiple operating system environments and a wide range of interface formats. For the developer of application software, this means that s/he is increasingly confronted with the task of adapting the application for operation in the new and different environments over the lifetime of the product. Therefore, the large demand for standard software and interfaces exists in order to obtain a general overview on the costs and duration of development. This article describes which requirements are to be taken into consideration in the implementation and how modern APIs (Application Programming Interface) and new standards such as OPC (OLE for Process Control) can simplify development and maintenance of CAN applications, thereb reducing the expenses for maintenance and development considerably.

This paper describes a general purpose architecture for designing distributed real time control systems based on component oriented system decomposition and CAN based communications. The basic philosophy of the architecture is to use an object-oriented analysis approach to partition the control system into logical subsystems, each of which is built from a set of co-operating software components. A CAN message distribution layer provides a transport service for messages sent between components, thus components can communicate in the same way whether they are on the same node or on different nodes. This 'virtual CAN bus' approach requires only a single CAN channel in the hardware chip. As a result highly scalable sstems can be developed, with variants of a products family being built from a common set of software components using a database to define the configuration. Legacy systems can be integrated using components which act as agents. A generic solution to the CAN duplicate message reception problem is presented using this design.

In many application areas of distributed systems based on serial busses like CAN high safety and reliability are considered as major functional requirements. In addition, the communication system has to cope with periodic as well as event-driven messages, which have to be transferred under hard real-time constraints. Especially where a considerable amount of event-driven data occurs, a flexible event-oriented scheduling strategy has to be preferred. But, event-oriented data processing and communication demand enhanced fault tolerance techniques. This article introduces a distributed system concept based on a redundant CAN architecture, which is able to meet the above requirements. Beside hardware replication, extensive fault tolerance protocol enhancements are provided, comprising fault detection, notification handling and recovery.

CAN is a successful fieldbus, used in many different application areas. Windows CE is a rather new product in the family of MS Windows operating systems. Windows CE targets not only PC companion devices, like handheld PC's, palm PC's and auto PC's, but also true embedded systems, like point-of-sale temrinals and set-top boxes. For both fields the combination of CAN and Windows CE offer interesting possiblities. The handheld and palm PC devices can be used by technician as maintenance tools, for example to spy on the ongoing communication in a CAN bus system, or can be used by system operators as small but elaborated terminals, for example to change parameters and process control settings. To facilitate the development of CAN based Windows CE applications, an extension to TNO's CAN Development Environment (CDE) was made. This CDE now has the possibility to run CAN sub-systems as a set of parallel running Windows applications communicating over a virtual CAN bus. As a result development times of CAN applications can be shortened and it makes hardware/software in the loop simulations of CAN systems much easier.

In this paper, Earliest Deadline First (EDF) scheduling algorithm has been translated to a CAN network by the use of a slightly modified CAN controller, called EDF controller. With this controller, the network can be modelled as a single, prioritised queue of messages. The messages use their time-to-deadline as their priority level. Using EDF scheduling on the network guarantees message transmission times. This can be also used in conjunction to the task scheduling algorithms in the CPU nodes to obtain a global scheduling policy related to the whole system. The information needed to apply a dynamic end-to-end scheduling algorithm can be automatically delivered into CAN messages when using EDF controllers.

With the steadily growing use of CAN devices within complex automation systems, the need for effective management solutions becomes more and more obvious. The spreading integration of CAN systems into Local Area Networks (LAN) provides the opportunity to build such solutions on intranet-based technologies like HTTP or COM/DCOM. Particularly the chances of a link between the intranet-stored information and the fieldbus layer let the development of a new generation of mangement tools be more than likely. Based on the illustration of principles for connecting fieldbus and LAN new concepts for the representation of CAN Higher Layer Protocol structures and data by intranet-based objects are introduced. Examples of practical realizations of the concepts for managing CAN modules prove the feasibility and show the prospects.

This paper shows methodologies used to develop a high-level simulation model of a quadruple CAN gateway. The project was done in tight cooperation between Audi and Motorola. The gateway model was integrated and simulated in the complete automotive network architecture together with models of all ECUs. Different simulation scenarios were run in order to measure CPU load, CAN bus load, message latencies in the gateway, memory requirements, etc. The modeling approach is described and illustrated with practical examples of the project. It is shown which results can be achieved, what there quality is and how they can contribute to the system development process. This paper shows and correlates practical experience of virtual prototyping with expectations frequently outlined in theoretical proposals.

Fieldbus networks should be able to support several kinds of data exchanges, characterized by very different requirements. The most popular solutions available today on the market are designed bearing in mind some sets of specific needs and usually are not always satisfactory for every kind of communications, which can be found in an industrial environment. In this paper a modification of the basic Controller Area Network (CAN) medium access technique is described which increases significantly the communication efficiency for the periodic exchanges of process data and for the messages devoted to high level functions, without affecting the very good responsiveness and flexibility of the conventional CAN protocol.

One of the possibilities to build robust communication systems with respect to their temporal behaviour is to use autonomous control based on the time-triggered paradigm. The FTT-CAN - flexible time-triggered protocol, relies on centralised scheduling but makes use of the CAN native distributed arbitration to reduce communication overhead. There, a planning scheduler is used within a master node to reduce the scheduling run-time overhead. On-line changes to the communication requirements can then be made under guaranteed timeliness. In addition FTT-CAN also allows an efficient combination of both time-triggered and event- triggered traffic with temporal isolation. In this paper, recent evolutions of the initial protocol definition concerning transmission of synchronous and asynchronous messages are presented. These consist in a time division of the elementary transmission window which optimises the available bandwidth for asynchronous messages, keeping the timeliness of synchronous messages without jeopardising their transmission jitter. A novel solution for the planning scheduler is also presented. It consists in an FPGA-based coprocessor which implements the planning scheduler technique without imposing overhead to the arbiter CPU. With it, it is possible to reduce strongly the plan duration thus allowing on-line admission demanded by system elements and, also, to extend the protocol application to high-speed networks.

This paper introduces a system which offers the possibility to access remote CAN devices over the Internet as if they were local. The system consists of at least two identical gateways connected over the Internet. Each of these gateways is connected to a CAN bus with at least one CAN device. This architecture offers the opportunity to use locally installed standard CAN tools to maintain remote CAN devices, independent from any higher layer CAN protocol which is used. There is a huge application potential not only for automation components but also for diagnostic purposes in cars and trucks. In order to ensure secure information transfer over the Internet, the system encrypts the transferred data on demand by using the secure socket layer protocol. Because most of the system is written in Java, it is possible to reuse nearly the whole system on different platforms.

In some industrial applications of CAN, the influence of interference becomes substantial. The paper describes measurements of the electromagnetic compatibility of CAN. The bus was submitted to standardized EMC tests and the results were evaluated so that some recommendations for designers could be given. These comprise basic design rules which increase the electrostatic discharge immunity, and the application of devices which provide protection against high-voltage burst transients.

Today, many Distributed Control Systems (DCS) communicate via a Controller Area Network (CAN). A failure in a DCS controlling a safety-critical application, e.g., an automotive brake system, can lead to significant economic losses or even the loss of human lives. Therefore, such DCS are usually designed to avoid failures in the service they provide to the user by including capabilities to handle the faults that could cause a failure. However, the testing of a safety-critical DCS’ capability to handle faults is a complicated task. A common test method is called fault injection. Using fault injection, realistic artificially generated faults are inserted into the system under test while the performance of the system’s fault-handling capabilities is measured. This paper presents some conceptually simple fault injection techniques that makes it possible to assess the handling of realistic node-level faults in a CAN-based distributed control system.

This paper presents the implementation of the CAN Calibration Protocol (CCP) on an electronic control unit (ECU) using the Society of Automotive Engineers’ (SAE) Recommended Practice J1939 multiplex communications protocol. SAE J1939 uses a CAN-based network protocol, to which we added CCP to support calibration and measurement activities during the development and test of new application software. The use of a commercially available PC-based tool for calibration and measurement provided a cost-effective solution to support these capabilities for this development program.

We present a schedulability analysis of CAN based system. Existing analyses consider that the worst-case occurs when all task (and messages) are released simultaneously (pessimistic assumption). In this paper, a systematic approach to precedence analysis is presented, considering the interference between task sequences instead of interference between single tasks. We also apply this analysis to a DX bus (a CAN based commercially available wheelchair controller), and we compare its predictions with those of a classical analysis. Results show that we obtain more precise estimations (=14%)

Automation systems of the past few years have been characterised by major changes. Today, PLC has established itself for controlling operative procedures as has decentralisation in the use of conventional field bus systems. A hierarchical structure of operative field buses, which assigns the suitable bus system to the re- quirements of the respective level, is becoming increasingly important, particularly in larger plants or factories. Therefore the fieldbus spectrum has been expanded by adding a safe bus system. SafetyBUS p is an open bus system for the serial transfer of safety-related data. It is based on the fieldproofed CAN-Bus system.The transfer of bit data is event-driven and also data fields (domains) can be transferred. In the form of telegrams of varying priority the data will be transferred. Telegrams requiring a safe shutdown have the highest priority, while telegrams dealing with configuration and pa- rameter settings have the lowest priority. The central theme is safety, and this is what sets SafetyBUS p apart from other bus systems used in automation technology. Safety is achieved by bringing the outputs to a safe, no-voltage condition in the case of an error. Safety-related networking offers users the same benefits to which they are accustomed from non-safety-related fieldbus systems, such as greater flexibility, reduced wiring and universal diagnostics. The three main aspects of SafetyBUS p are as follows. The decentralisation of the I/O-level, the direct connection of safety-related sensors and actuators and the safety-related coupling of several PSS programmable safety systems. SafetyBUS p enables the user to create a safe network (e.g. of Emergency-Stops, safety gates, ...) using decentralised I/Os or to incorporate safety- related components (e.g. light guards). This is a great benefit to those who are in- volved in plant and machine engineering, process engineering and the automotive in- dustry. The SafetyBUS p system is approved for category 4 in accordance with EN 954-1 and meets the requirements of AK 6 in accordance with DIN V 19250. This means that its use is guaranteed for safety applications with a defined safe condition for the areas in which these standards are valid. A safe condition is defined as a no- voltage condition. In accordance with valid standards and regulations, SafetyBUS p offers new solutions for configuring networked machines and for modular plants dis- tributed over a wide area.

Today, the integration of fieldbus devices into the business LAN of an enterprise is usually accomplished by a proprietary OPC solution. This paper describes a more ge- neric and platform independent approach to represent CAN system information and to manage CAN process data. The CANopen Markup Language (CoML), an XML appli- cation, was developed in conjunction with several Java CoML tools to achieve this goal. The main benefit of using XML to describe CAN systems and CAN process data lies in the standardized way to represent structured data enriched by meta-data. XML and the corresponding Document Object Model form a basis for rapid development of CoML applications which provide platform independent access, visualization and storage of CANopen setup information and process data. Due to the intrinsic inter- changeability of XML information, CoML documents can be processed and evaluated not only by dedicated CoML applications but also by a wide variety of common XML tools like XML editors or XML databases for example. Since XML documents are espe- cially well suited to be deployed to the WWW, this approach also facilitates convenient access to CAN data via the Internet. This paper gives an introduction to the CANopen Markup Language, the EDS2CoML translator and the CanInvestigator CAN monitoring tool.

The wide use of CAN-based distributed systems in embedded control applications triggered the research on the problem of transmission network induced jitter in control variables. In this paper we introduce a variant of the classical Genetic Algorithm, which we call Progressive Genetic Algorithm, and show how it can be used to reduce jitter suffered by periodic messages by imposing them initial phasing and/or changing this parameter on-line. The approach can be applied when there is synchronisation between nodes (e.g. using time-triggered communication on CAN) or when a centralised dispatching scheme such as the one of FTT-CAN [1] is in use. The algorithm was tested with two well-known sets of messages, the PSA [2] and the SAE [3]. It is shown that it is possible to completely eliminate jitter if the adequate transmission rate is available and, if not, a satisfactory reduced jitter can be obtained.

"The standard ""trunk branch"" topology described by the ISO High Speed Physical Layer for CAN based networks does not allow a flexible network deployment in applications due ist topology limits. One solution to realize multidrop lines is to replace tees with multiports, allowing more than one device to be connected to each branch. This paper discusses the influence of multiports with regard to signal transfer characteristic on a system level. Network simulations and test data prove multiports can be used in CAN based networks with an ISO High Speed Physical Layer when the maximal trunk length is shorted by 25 percent. All other topology rules of the regular trunk branch topology must also be followed."

CANopen-based communication also becomes popular for failure-tolerant systems. A typical application of that type is the area of marine automation systems, e.g. ship alarm, monitoring and control systems in any kind of ships like product carriers, container ships, passenger vessels, ferries and cargo ships (Fig. 1) . The main rule to be met in that type of application is, that the system must tolerate at least one arbitrary single component failure. This implies that a general redundant system configuration, including the communication system, has to be provided to fulfill the requirements of a failure-tolerant system. This article describes a CANopen-based communication system that fulfills the requirements of a failure-tolerant system. It was developed by IXXAT Automation for the Norwegian ship automation systems supplier Kongsberg Norcontrol. The system already operates very successfully in many applications. The implemented system concept is now established as the basis for a CANopen-based standard in ship automation (CiA SIG Maritime Electronics).

In some areas in which CAN is utilized the systems involved are subject to more stringent safety requirements. Such systems need to be fault tolerant to a certain extent, and the redundant design of communication buses offers the required property. Using CANopen as higher layer protocol requires some supplements to the standard communication channels. This paper looks at the possible error types occuring in a CAN network, the strategy of redundancy and the CANopen protocol enhancements. Any additional protocol definitions described here are proprietary so far. Further standardization work done by a CiA interest group may be expected.

The Controller Area Network (CAN) exhibits a highly reliable and predictable behavior, as it is required by embedded real-time control applications. Although CAN provides a consistent view of every transmitted frame among all peer CAN controllers in most fault scenarios, the frame-level consistency ma be lost due to an error during the last two bits of a frame followed by an immediate sender crash, as indicated by Rufino at al [17]. Previous Approaches to solve this problem require modifications to the software-level communication protocol, which result in additional communication load. This would affect the performance parameters of the real-time application system. In this paper, a hardware component (SHARE: Shadow Retransmitter) is suggested, which undertakes the retransmission of frames in such cases transparently, i.e. the actions of a SHARE are not visible to other CAN nodes, and do not influence the performance parameters of the existing application system.

"Software tools can be helpful in understanding the behavior of complex technical systems. Quite often, however, present-day tools have to be accepted by the user on an ""as is"" basis without an easy way to customize the tool. New ideas and techniques of modern software technology promise a much higher degree of adaptability of software systems and, in particular, of graphical user interfaces (GUIs). This paper presents an architecture and a prototypical realization of an experimental tool designed along the lines of these novel ideas. The tool is based on a hierarch of model layers for analyzing the temporal behaviour of CAN-systems. The underlying mathematical key ideas include: worst case analysis of response times, probabilistic error model, and quality measure of timeliness. The architecture allows to easily extend the system and to exchange, among other things, the basic equations, the algorithms, and the probability distributions involved without affecting other parts of the system."

The paper describes Toshiba's new multiple - TOSCANA module, a 2.0B compliant CAN controller module with a flexible and configurable-shared message buffer system. The new multiple-CAN module is based on Toshiba's well established TCAN 2.0B CAN module with 16 message buffers including timestamp, proven conformance to the emerging ISO 11898 test standard and implemented in several microcontrollers. The multiple-CAN module implements individual assignment of mailbox-RAM to one of the three protocol controllers and offers a mechanism for automated Bridge (Gateway) functionality without CPU interaction. The implementation in 2 high performance automotive RISC microcontrollers (one of powertrain-management and another one for driver information) are first applications for the new CAN Core.

"Connecting microcontrollers, sensors and actuators by several communication systems is state of the art within the electronic architectures of modern vehicles. Today's Ier-Area-Networt (CAN) communication protocol. The arbitrating mechanism of this protocol ensures, that all messages are transferred according to the priority of their identifiers and the message with the highest priority will not be disturbed. In the futuresome mission critical subnetworks within the upcoming generations of vehicle systems, e.g., x-by-wire systems (xbws), will require additionally deterministic behavior in communication during service. Even at maximum bus load, the transmission of all safety related messages must be guaranteed. Moreover, it must be possible to determine the point of time when the message will be transmitted with high precision. One way to solve this issue using CAN is the extension of the standard CAN protocol to a time triggered protocol TTCAN. The communication is based on the priodic transmission of a reference message by a time master. This allows to introduce a system wide global network time with high precision. Based on this time the different messages are assigned to time windows within a basic cycle. A big advantage of TTCAN compared to classic scheduled systems is the possibility to transmit even triggered messages in certain ""arbitrating"" time windows as well. These time windows, where normal arbitration takes place, allow the transmission of spontaneous messages. This paper describes this extension ""TTCAN"" as it is accepted in TC22/SC3/WG1/TF6 (ISO11898-4) as the common base for the standardization work."

"Shortened time-to-market, reduced lifetime and increased product flexibility are some of the attributes of high-tech products requested today. Smart Flash Micro-Controllers with integrated CAN Controller supports these requests by using the CAN bus in two ways: • To optimize the control and the communication of the different modules of the application in order to have state-of-the-art functions in a competitive product • To update the customer Flash program memory and the data EEPROM by In-Situ- Programming (ISP), in order to improve easily the customer code or to add new features and parameters to embedded applications in the field. The last point requires a strong level of security to avoid any locking situation in the Flash memory up-date procedure via CAN bus initiated in an embedded application. This paper introduces new low-pin-count Flash Micro-Controllers featuring a powerful combination of Customer Flash Memory, separate Boot Flash Memory, on-chip EEPROM, RAM, 10bit ADC, an advanced CAN Controller and other well selected peripherals. A boot loader and numerous Application Program Interface (API) software support the customer to set-up embedded applications in an efficient way. Details of these 28-pin (T89C51CC02) and 44-pin (T89C51CC01) microcontrollers part of the new """"CANARY"""" family as well as examples on how it will help to improve system flexibility of a competitive CAN based application, are presented hereafter."

In industrial processes it is usual practice to configure a communication system when it is put into operation with parameters pinned down to constant values, e. g. the data rate, during the whole runtime. Such a predefined stiff communication behaviour can- not be optimal, it may even collapse in critical situations of the industrial process for which it is responsible. In this paper a system is presented allowing the permanent and flexible online- adjustment of important configuration parameters of the CAN-system to the real re- quirements of an industrial process which may even vary heavily. During the operat- ing time it is possible to change e. g. the identifiers, data rate, inhibit time, the bus- allocation procedure or even the bus structure. The data traffic is optimised by a net- work management. It comprises a central network manager and network assistants placed decentrally in the controllers of the communication partners in the CAN- system. The network assistants are instructed to carry out the optimisation interven- tions calculated in the network manager. The building up of the system and first expe- riences are presented.

This paper will explain how to measure performance on DeviceNet. Understanding the fundamental performance attributes of a DeviceNet network is basic to achieving network design goals, optimum performance and reliable operation. This paper will provide an overview of the methods, software and hardware used at Rockwell Automation to measure DeviceNet performance.

The communication in the classic CAN network is event triggered; peak loads may occur when the transmission of several messages is requested at the same time. CAN’s non-destructive arbitration mechanism guarantees the sequential transmission of all messages according to their identifier priority. For hard real-time systems, a scheduling analysis of the whole system has to be done to ensure that all transmission deadlines are met even at peak bus loads. For a RTOS that is based on static cyclic scheduling of all tasks, system integration and composability are served when the communication on the CAN network also fol- lows a synchronised schedule. The time triggered communication option of the forthcoming new edition of ISO11898-1 describes the prerequisites needed for the synchronisation of all nodes in the CAN net- work. Based on the synchronisation of the nodes, the time triggered communication facilitates also the establishment of a global time in higher-layer protocols. A higher- layer protocol above the unchanged standard CAN protocol is in the process of stand- ardization by ISO TC22/SC3/WG1/TF6, as ISO11898-4. In parallel to the standardization process, Bosch has implemented the time triggered communication function into a CAN IP module that maintains the cyclic transmission schedule autonomously, not depending on software control. This paper describes a CAN network with time triggered communication consisting of CAN controllers with autonomous message scheduling. ?The communication in the classic CAN network is event triggered; peak loads may occur when the transmission of several messages is requested at the same time. CAN’s non-destructive arbitration mechanism guarantees the sequential transmission of all messages according to their identifier priority. For hard real-time systems, a scheduling analysis of the whole system has to be done to ensure that all transmission deadlines are met even at peak bus loads. For a RTOS that is based on static cyclic scheduling of all tasks, system integration and composability are served when the communication on the CAN network also fol- lows a synchronised schedule. The time triggered communication option of the forthcoming new edition of ISO11898-1 describes the prerequisites needed for the synchronisation of all nodes in the CAN network. Based on the synchronisation of the nodes, the time triggered communication facilitates also the establishment of a global time in higher-layer protocols. A higher- layer protocol above the unchanged standard CAN protocol is in the process of stand- ardization by ISO TC22/SC3/WG1/TF6, as ISO11898-4. In parallel to the standardization process, Bosch has implemented the time triggered communication function into a CAN IP module that maintains the cyclic transmission schedule autonomously, not depending on software control. This paper describes a CAN network with time triggered communication consisting of CAN controllers with autonomous message scheduling. ?The communication in the classic CAN network is event triggered; peak loads may occur when the transmission of several messages is requested at the same time. CAN’s non-destructive arbitration mechanism guarantees the sequential transmission of all messages according to their identifier priority. For hard real-time systems, a scheduling analysis of the whole system has to be done to ensure that all transmission deadlines are met even at peak bus loads. For a RTOS that is based on static cyclic scheduling of all tasks, system integration and composability are served when the communication on the CAN network also follows a synchronised schedule. The time triggered communication option of the forthcoming new edition of ISO11898-1 describes the prerequisites needed for the synchronisation of all nodes in the CAN net- work. Based on the synchronisation of the nodes, the time triggered communication facilitates also the establishment of a global time in higher-layer protocols. A higher- layer protocol above the unchanged standard CAN protocol is in the process of stand- ardization by ISO TC22/SC3/WG1/TF6, as ISO11898-4. In parallel to the standardization process, Bosch has implemented the time triggered communication function into a CAN IP module that maintains the cyclic transmission schedule autonomously, not depending on software control. This paper describes a CAN network with time triggered communication consisting of CAN controllers with autonomous message scheduling. The communication in the classic CAN network is event triggered; peak loads may occur when the transmission of several messages is requested at the same time. CAN’s non-destructive arbitration mechanism guarantees the sequential transmission of all messages according to their identifier priority. For hard real-time systems, a scheduling analysis of the whole system has to be done to ensure that all transmission deadlines are met even at peak bus loads. For a RTOS that is based on static cyclic scheduling of all tasks, system integration and composability are served when the communication on the CAN network also follows a synchronised schedule. The time triggered communication option of the forthcoming new edition of ISO11898-1 describes the prerequisites needed for the synchronisation of all nodes in the CAN network. Based on the synchronisation of the nodes, the time triggered communication facilitates also the establishment of a global time in higher-layer protocols. A higher- layer protocol above the unchanged standard CAN protocol is in the process of stand- ardization by ISO TC22/SC3/WG1/TF6, as ISO11898-4. In parallel to the standardization process, Bosch has implemented the time triggered communication function into a CAN IP module that maintains the cyclic transmission schedule autonomously, not depending on software control. This paper describes a CAN network with time triggered communication consisting of CAN controllers with autonomous message scheduling.

Motivated by the necessity of connecting CAN nodes without high installation expenses, the principles for infrared light based data transmission were developed applying the inherent CAN protocol. Unlike in concepts using radio transmission bitwise arbitration and acknowledge remained available. A first functional example for an infrared CAN Bus, coupled to standard CAN-controllers, has been implemented. Different configurations have been tested. The presented system opens the way for new applications of CAN as for data acquisition in explosive, liquid or any transparent substances, for short term experimental installations and in automation systems where wired networks are not applicable as in rotating systems.

With the introduction of OSEK and the increasing number of ECUs in car’s body, automotive network requirements have changed significantly in the last few years. 8-bit micro controllers are and will stay widespread in a majority of automotive body applications. While a wide variety of powerful CAN controllers are available on the market for 16- and 32-bit micro controllers, 8-bit micro controllers still have to spend to much CPU resources for CAN message management. This paper presents a new generation of CAN controllers optimized for 8-bit micro controllers and developed to meet body applications’ needs.

The latest automotive bus architectures deman gateway devices supporting up to 5 CAN channels. NEC has responded to this demand with a scalable FCAN macro In addition to multiple CAN interfaces, NEC has developed 'ELISA', a sophisticated Event Processor supporting Gateway tasks between these interfaces. Furthermore, a software tool is available to enable users to master the complexity of FCAN and ELISA. NEC's FCAN software tool not only provides a CAN driver library with an interface to OSEK NM, but also a graphical setup utility for initializing the entire FCAN and the specific CAN protocol engine according to bus parameters and the Network Communication Matrix. This utility further helps in implementing ELISA's command list code for the event driven Gateway tasks.

In this paper, we introduce an object-oriented client-server system which is primarily based on Jini and CAN, where Jini is used as a middleware architecture which offers devices and their services to a network, such as the internet. The dynamic integration of services and the feasibility of network pluggable devices are the major benefits of using Jini. As Jini offers the ability to move code over a network, it is possible to use device-specific application code and device specific options dynamically. The application to access a specific device is transparently transferred to the client. For demonstration purposes a prototype to access CANopen devices over Jini was developed. The client, a PDA (personal digital assistant) with a small embedded Java Virtual Machine is used to access CAN devices connected to an embedded Java system called TINI. As nowadays no devices directly supporting CAN and Jini are available, so called proxies are used to tie up the systems to the Jini community.

The choice of the appropriate fieldbus system for a specific application is not always driven by technical features, cost and availability considerations. System Integrators are often forced to use several fieldbus systems, as many customers demand to pro- vide their favourite bus. Microsoft Windows operating systems are accepted world wide, and thus provide a common base independent of the underlying fieldbus system. However, there is no common upper interface for the various bus solutions. Each bus requires specific tools and a change of the bus system leads to significant adaptations in the user and control programs. These efforts can be reduced by using a generic fieldbus applica- tion program interface for Windows.

This paper discusses the feasibility of porting the existing DeviceNet protocol, which utilises only Standard CAN (11-bit Identifier), onto Extended CAN (29-bit). It highlights on the background, limitations, and problem analysis of the existing DeviceNet protocol over Standard CAN, introducing the new DeviceNet over the Extended CAN concept (DeviceNeX). The advantages and disadvantages of the DeviceNeX protocol will also be discussed in-depth. Finally the issues of Conformance, Physical Layer, and Interoperability Testing with DeviceNeX will be addressed, followed by the conclusion.

With the increasing popularity of distributed and open frameworks, the trend of connectivity has extended to real-time control systems such as CAN. A generic middleware for CAN will facilitate the design, implementation and management of distributed applications for CAN systems, instead of programmers having to build custom made applications. This paper describes current approaches to tailoring existing middleware frameworks to the specific features of embedded systems in general, and CAN in particular.

The Controller Area Network (CAN) protocol incorporates a powerful means of seamlessly preventing data corruption during message collision. This arbitration process and its relationship to the electrical layer variables are explained. Techniques to force message collision and test arbitration are demonstrated with strategies to leverage arbitration as a quantitative benchmark in safety-critical systems. The benchmark is then applied to several example systems and results provided for comparison.

First the main benefits of distributed processing will be discussed and the require- ments summarized, which have to be met for the implementation of intelligent distrib- uted systems. With the additional CANopen standard DSP 302 a framework for distrib- uted systems is now specified which, besides other items, comprises the introduction of network variables, the support of program download and control, a standardized system boot-up procedure as well as the definition of a configuration management instance. As system configuration is one of the most important practical aspects for the establishment of distributed intelligent systems, an introduction into the configu- ration process of those systems will be given and a versatile configuration tool shortly presented. Finally, it is shown how the implementation of programmable CANopen devices can be facilitated considerably on the basis of an available CANopen Master software package.

We have developed a single-chip network-interface LSI that integrates a 500V capacitive isolated digital coupler, a 5V / 100mA voltage regulator and a 1-Mbps CAN transceiver. The coupler uses high-voltage, on-chip-isolator technology including trench isolation with buried oxide on SOI (Silicon On Insulator). The switching-voltage regulator of a step-down DC-DC converter that is connected to the network power line (11 to 25 V) supplies a constant 5V voltage to the transceiver circuit. In addition, a network-power-supply state-monitoring function, which reports the voltage drop to a CAN controller through the insulated barrier, is provided. By connecting the SOI substrate to the network-power supply line, the electric potential that the transceiver is referenced to can follow the electric potential shift of the network by common mode noise and thus enable a dependable operation. The physical-layer interface LSI can reduce the power consumption to 20% and reduce the mounting area of the interface circuit to 50%.

The low-processing power microcontrollers used within typical CAN nodes, usually place tight limits on the complexity and flexibility of on-line message scheduling systems. One solution to break this barrier is to transfer the scheduling task to a hardware implementation. A traffic scheduling and schedulability analyser coprocessor is presented in this paper. The coprocessor generates message schedules for the master node CPU of a fieldbus system, leaving it just with the dispatching task. Scheduling can be made to follow one of three different policies. The number of messages to be scheduled and their parameters can be changed dynamically. To support on-line admission control of new messages, the coprocessor implements a schedulability analyser function. The coprocessor was designed to support the FTT-CAN protocol, but it can be adapted to any other fieldbus using centralised scheduling. The description presented here is focused mainly on the coprocessor’s overall functionality and interface with the node CPU. To characterise its performance, calculated response times are presented.

Modular design and networked solutions are the basic answers to master complexity of today’s and future systems. Complexity will even grow dramatically as the desired functionality by the end user is increasing drastically. A basically efficient approach to achieve proper interoperability in distributed systems is to apply standard 'layers' onto which the application itself is built, to specify standard layers as high as possible while minimizing the individual application parts and to check the functionality of these layers by sufficiently efficient conformance tests. In automotive and other applications these 'standard' layers comprise – from the lowest to the highest level – the 'transceiver' layer, the 'network' layer, a 'device driver interface' layer and the 'operating system' layer, which currently is the final interface to the application. In automotive applications the communication layers mostly are based on CAN protocol complemented by CAN software drivers interfacing the operating system OSEK/VDX.This stack of 'standard' levels provides a powerful and neutral interface to the application. But experience over the last years has shown that the implementations of the individual levels differ in their behavior. This is due to several reasons such as the specifications of the individual levels are not precise enough, they are ambiguous, they difficult to implement because of their complexity. Even if there formal and executable specifications for instance based on state machine languages, implementations show defects because the implementers try to optimize and thus they violate unknowingly for instance the constraints related to local variables. c&s group has worked in the field of conformance tests since more than 5 years and thus has contributed for instance to the development of the ISO CAN Conformance test standard. As a complement to the ISO standard c&s has specified and implemented conformance tests for the CAN register interface and for the related 'higher layer' software drivers. Furthermore c&s is cooperating in a group of auto manufacturers – Daimler Chrysler, BMW, Audi, Volkswagen, PSA – to specify and implement conformance tests for a new generation of fault tolerant CAN transceivers. Tests for the communication and network management part of OSEK/VDX have been specified and implemented. The OSEK tests go beyond the 'normal' test methods which typically check all possible transitions from each state to its neighbor states, because this neglects some typical implementation 'faults', which are due to some optimization side effects. Looking at the 'tests chain' comprising all the levels being involved to build the bridge from one application on one module to the other modules a high degree of confidence in the conformance of the whole chain is provided. The present paper discusses the constraints given by the distributed system in conjunction with the philosophy how to derive tests on the various levels, how to implement the tests and typical test problems and achieved results.

This paper describes the sysetem reaction time modelling and the required verification of the model for use in the DeviceNet Modeling Software (DMS) from Rockwell Automation. While the behaviour of a bus system like DeviceNet is fairly clear, combining two independent sysetms, e.g. a PLC and a scanner, makes system throughput estimation much more difficult. Bus behaviour models are described that cover all four I/O exchange mechanisms defined in a master/slave relationship within DeviceNet: Strobbing, Polling, Change of State and Cyclic. Several types of data exchange mechanisms between DeviceNet scanners and PLC CPUs are discussed. Susequently, overall system reaction time models are derived that incorporate the various I/O exchange types. Furthermore, the validity ranges and the limitations of the theoretical model and the verification test methods are described. The DMS uses the models derived with the above method. It allows to estimate the system delay behaviour (minimum, typical, maximum) of single master DeviceNet systems from inputs (bus or local) to outputs (bus or local). This software comes with a comprehensive set of Rockwell Automation products already incorporated and allows for easy integration of other DeviceNet products.

The use of distributed safety critical applications increases constantly. This new trend requires detailed knowledge about how to design the system to reach dependability. A failure in embedded distributed computer systems can result in high costs, e.g. goodwill for the company, loss of market shares, redesign of the system and most important, failure to meet personal safety criteria. Dependability can be achieved through many methods and techniques but first after a thorough requirement analysis of the system. It is furthermore important to measure and assess these properties of the system. The Swedish research project PALBUS handles these issues, how to design, develop and analyze distributed control systems with dependability in mind. The project faces dependability considerations from various aspects, for instance the importance of clear requirements and consistent terminology, wise utilization of existing protocols, e.g. CAN, intelligent fault models and development principles to reach specified fault tolerance and finally through thorough methods and techniques for verification and validation of the implementation. Knowledge from many different companies is distributed through their specific knowledge about for example communication protocols. This paper describes the PALBUS project and extracts information that could be used for dependability assessment. To do a thorough description of dependability assessment is beyond this paper whose purpose is to give a survey and some interesting suggestions concerning dependability.

"""So far potential users of ARM 32-bit RISC-Controllers always had the choice between using predefined Standard MCUs with given features or to build up a custom specific solution around the ARM core. Looking at the second solution, it offers the possibility to include exactly those IPs which are needed for a certain application, but on the other hand, this solution requires a high investment, since it is made using a full-custom approach. OKI´s POWERED GATE TechnologyTM is an alternative solution to this problem. The POWERED GATE device is a preproduced ASIC which already includes the ARM7TDMI –Core and basic functions like Flash, SRAM, A/DC and clock generator. All other peripherals will be realized in a Sea-of-Gates area, that offers 100K usable gates on chip. With an extensive library of existing IPs, including network functions like CAN, VAN, USB, timers, UART,.. it is now possible to design a custom ARM MCU at the cost and development time of a standard ASIC."""

The paper describes the research project „Standardisation of the Open Communication in mobile Construction Machines“. The project created the bases for the use of CANopen in mobile construction machines. Specific device profiles for construction machines were defined and suggested for standardisation. A mobile excavator was equipped with CANopen, so that various devices are able to exchange data.

A method for distribution of intelligence is presented in which the Object Oriented Paradigm is used in software as well as in the communication protocol and appli- cation level. Practice has shown that an optimal distribution of functionality can reduce bus- load, increase flexibility and improve the diagnostic capabilities. Some rules will be presented in order to reach this optimum. The relationship between network- management and application software will be addressed. It is also shown that ef- forts (and costs) for developing and maintaining software can be reduced. It will be explained why CAN is a suitable network for distributed intelligence. Some problems facing distributed intelligence will be discussed and solutions will be given. Furthermore some methods will be given to increase the availability (up- time) of distributed systems by means of Smart CAN bridges and selective redun- dancy.

Web-based management solutions for fieldbus systems have become state of the art. A framework based on descriptions in XML (eXtensible Markup Language) allows an easy mapping of a device's management functionality to web pages used as man- agement front-ends. In most cases, the XML representation can be used directly in the browser. Another way is an off-line generation of HTML-pages by means of scripts and style sheets. The management framework supports several design scenarios. It is possible to gen- erate XML descriptions from a functional decomposition of a device, or on top of ap- plication profiles and device descriptions. Using an extensively linked set of XML files, hierarchical descriptions describe the spectrum from single device up to com- plete systems. Examples of a practical realization prove the feasibility of the concepts. Interfaces to the common software design process are pointed out. Problems and benefits are dis- cussed, and further trends are highlighted.

In this paper the results of a CAN-based distributed real time adaptive control system of a small dc-motor are presented. The goal was to measure the performance of a pole-placement adaptive control algorithm under several jitter conditions due to MAC.

Powerline Interfaces enhance the fields of application for CAN. Notably effects can be achieved in the area of automation of rolling stock. New ways of communication become possible. Flexible network configurations during the composition of a train demand rugged network connections. Powerline provides an effective solution for this problem. With simple means at low cost a reliable communication can be realized. Industrial applications prove already the capability of this new interface.

Distributed systems have been demonstrated as one of the best options when implementing industrial control systems due their simplicity and power. Following this line, our group has proposed Rule Nets (RN) as a HLP over CAN for the implementation of Distributed Expert Systems (at 6th ICC), obtaining excellent results although RN lack of continuous control capabilities. To provide these new features, in this article, the use of Neural Networks (NN) alongside of RN, as an application level over CAN is proposed, offering an intelligent and hierarchical environment of distributed control, where continuous control loops are being supervised by an expert system. This technique is now being applied in the integral control of an automated house, where NN implement the control loops (heating /cooling, brightness, etc) and advanced features (voice, fingerprints and shape recognition, etc.) and over them RN supervise the operation of the system, under normal operation conditions and exceptional situations.

This paper describes a mechanism for multi-axis coordinated motion control via the CAN bus. The trajectory generation function is shared between the CAN host and CAN servo nodes. The position loop is closed in the CAN servo node. The trajectories of each axis are de-coupled, and all axes are synchronized via the CANopen Time Stamp message.

The TTCAN protocol is a new development in CAN technology that specifies a time-slot based communication mechanism. TTCAN technology avoids the transmission collisions commonly found in standard CAN networks. In TTCAN, all the message instances are transmitted only on previously allocated time-slots. No other instance may be transmitted on an allocated time-slot, so transmission collisions are avoided. Before transmitting a message set over a TTCAN network, it is necessary to create a valid scheduling table that specifies how the time is discretized into time-slots and how the message instances are allocated into those time-slots. Building a valid optimized scheduling table that follows the TTCAN specification isn’t trivial. Additionally, several distinct scheduling tables may be built for the same message set, so it is necessary to use some quality criterion to select one among all. Typical message sets include a large number of messages, making manual scheduling a very hard and error-prone process. This means it is desirable to use automated tools that compute a feasible scheduling table automatically for a given message set. In this paper, we present a scheduling tool for TTCAN networks that generates a valid scheduling table using a stochastic optimization algorithm. The tool attempts to optimize the scheduling table so it will generate solutions with low jitter. The tool was applied to two well known message sets used in the automotive industry and results are positive.

To access mobile and moving CAN fieldbus systems a wireless approach is often a good solution. For short-range wireless communications using RF links the Bluetooth Wireless Technology has been introduced. This paper describes the use of the Bluetooth Wireless Technology beyond its primary mission – Bluetooth links as a transport media for CAN data. Furthermore, a practical implementation of a Bluetooth CAN interface is presented.

Sophisticated drive-by-wire systems require extensive set-up and self-check procedures. Due to the complexity of the systems, code updates are used frequently, initially during the test phase, and later during the lifetime of the product. An efficient implementation of all these features in addition to the normal operating modes demands strong flexibility in the TTCAN/CAN microcontroller. The following functions will support these requirements: - On-the-fly selection of all features of message objects (channels) including TTCAN/CAN, Receiver, Receiver Buffer or Transmitter mode. This permits efficient use of the full power and buffer space of the device in all modes. Each channel uses its own independent control and buffer space. - Flash memories for code, boot and application parameters are updated via CAN bus by In-System-Programming (ISP). - Full secured operations maintain system functionality in all modes. This paper describes the new TTCAN/CAN Flash microcontrollers featuring a powerful combination of ARMTM core, Flash Memories, the advanced TTCAN/CAN Controller with four CAN bus interfaces as well as other powerful peripherals. In-System-Programming (ISP) and numerous Application Program Interface (API) software accelerate the set-up of embedded applications. This article presents the main features of these smart TTCAN/ CAN microcontrollers and provides examples of how it will help to improve system flexibility of a competitive CAN based application.

In this paper, an ASIC is presented, which combines a 12bit analogue digital converter with an 8bit micro controller and a CAN controller on a single chip. This solution allows the construc- tion of a wide field of intelligent sensor systems with minimal area requirements and has the capacity for possible data processing. The free programmable micro controller can be used to control the measurement cycle, preprocess the sampled data and transfer it via the CAN-Bus. The implementation of various CAN standard protocols is possible, such as CANopen and De- viceNet. Additionally, a complete system including the proposed ASIC for Wheatstone bridge sensors is described and a simple algorithm for characteristic curve linearization is presented.

ISO TC22/SC3/WG1/TF6 has standardised (as ISO CD 11898-4) an additional layer to the CAN pro- tocol, “Time Triggered Communication on CAN”. This new standard specifies how a periodic transmission schedule is maintained, how a global system time is supported, and provides fail- ure handling procedures as well as application interfaces. The time triggered communication is built upon the unchanged CAN protocol (ISO 11898-1). This allows a software implementation of the time triggered function of TTCAN, based on existing CAN ICs. The high precision global time however requires a hardware implementation. A hard- ware implementation also offers additional functions like time mark interrupts, a stop-watch, and a synchronization to external events, all independent of software latency times. This paper describes the principles of how a TTCAN network’s clock speed and clock phase is synchronized to an external time base or to another TTCAN network.

This paper will cover several current applications of SAE J-1939 CAN using both registered and proprietary addresses for total machine control. In addition to the expected control schemes, the paper will unveil several unique approaches to long- standing problems and their method resolution. Also included will be several glimpses of future uses of CAN on Mobile Equipment. The paper will cover both On Highway and Off Highway applications along with some unique monitoring and trouble shooting applications. Applications cover machines requiring thousands of modules per year to one representing less than 100 per year.

This paper touches on the current success of CAN, including its success in expanding into the American CAN market. Additionally, this paper takes a look at CAN as a technology component and illustrates the need for a well-designed test strategy that brings products to market in an efficient and timely manner. We talk about the issues facing test engineers and what to look for while solving applications that involve CAN as a component.

"""The success of CANbus in commercial automotive applications effectively guarantees long-term availability and support. The fact that CAN is inherently rugged makes it an attractive proposition for military vehicle (vetronics) applications. In practice though, vetronics applications are characterized by the need for absolute interoperability. More than just electrical or data transfer protocols, this encompasses a worldwide “plug and play” mentality across multiple vendors, vehicles, and subsystem functions. In addition, specific operational requirements may include the field reconfiguration of subsystems in order to preserve critical vehicle functionality and safety. This paper details the history and implementation of MILCAN, a protocol developed under the auspices of the International High Speed Data Bus User’s Group in order to address the whole range of military vetronics requirements. Specific protocol issues covered include the benefits of a functionally partitioned architecture, frame formats, determinism, and message latency. MILCAN is derived from other CAN protocols such as the CUP protocol developed byt he German BWB, ISO 11898, SAE J1939, and CANopen."""

DeviceNet utilises a variety of possible I/O connection services that allow for deterministic optimisation of CAN bus load performance. This paper reviews the theory of bandwidth capability of contention-based communication schemes such as CAN and Ethernet. It studies the DeviceNet I/O connections for efficient use of CAN busload to minimise any possible message latencies due to high use of the bus bandwidth. It also shows the use of message prioritisation to ensure throughput of high priority information.

Wired industrial LAN are usually based on fixed position of the sensors/activators, constituting the first level of the CIM architecture (Computerized Architecture Manufacturing). However, necessity of mobile producers/consumers appears, and wireless LAN connections seem to be the right solution. Although the original functionality, applications field of the BT system (Bluetooth) are very different from an industrial LAN, we explore the possibility of interconnecting these two types of LAN. An application between a Bluetooth wireless network and a CAN wired network is explored in detail in the sense that we try to maintain in the BT_Network, the determinism supported by the CAN via its CSMA/CA arbitration access bus.

TTCAN is a time triggered layer using the CAN protocol to communicate in a time trig- gered fashion. As TTCAN is based on CAN it uses the power of CAN´s error detection mechanisms and robustness, but it also provides a step towards determinism and time triggered technology. Future system architectures will include applications that need to access more than one TTCAN controller. This article describes how to build fault-tolerant TTCAN networks, in particular the mechanisms to synchronize different TTCAN busses. It is shown that it is very easy to implement a synchronized network of any reasonable redundancy level, even if non-trivial architectures (for instance more than a simple dual channel network) are involved. Moreover, this synchronization can be achieved even when the individual TTCAN busses use different time bases without ever violating the modular integrity of one single bus.

"""The integration of automation systems in a general management and service infrastructure, like for example a company's logistic and management network, as well as the use of high level languages to support state of the art software development is a major challenge in automation engineering. Embedding devices in information technology infrastructures and applying modern software development methods require the representation of devices on a higher level of abstraction. Once low level device facilities and communication details are encapsulated and represented by a software entity with respective interfaces, the application software development gets much more efficient. This paper introduces a system which offers the opportunity to automatically discover and classify CANopen devices running in a CAN system. An XML description of the discovered devices and their interfaces is generated, which is then used to automatically generate Java control software for these devices including high level application interfaces. The XML description offers a lot of additional possibilities like automatic generation of web interfaces, integration in document management systems, access to database systems and Internet-based services in general. The current system setup consists of an Industrial PC-based controller running either Windows NT or the real time operating system RMOS offering a real time Java Virtual Machine named RTVM. The goal of the presented system is, not to be concerned with low level device facilities and communication protocols but to easily develop applications using high level components wherever possible to support modern software development processes and to seamlessly integrate automation systems in a general information technology infrastructure."""

Bridges, gateways and routers cannot only extend the maximum length of a CAN based network, they can also help increase overall bandwidth, as network segments can be made shorter and faster and network segments only receive network traffic that involves nodes connected to it. In the past, configuring a CAN bridge was a time consuming process, as the bridge had no way of knowing which messages need to be forwarded to which network segments. This changes if the protocol used is a higher-layer protocol such as CANopen. For CANopen a bridge or router can be build to be self-learning: due to a pre-defined connection set for identifiers, the device just listens to the network traffic and learns “on-the-fly” which messages need to be forwarded to which segments. This paper summarizes the benefits and drawbacks of bridges and routers in a CANopen environment and gives an implementation outlook for a scalable, smart, self-learning router.

Substantial work has been done on the problem of optimizing messages transmission on the Controller Area Network (CAN). Due to its hard combinatorial nature, CAN is a challenge for those who deal with the analysis of optimal ordering. In this paper, we present a new scheme on the worst-case response time of messages, considering a theoretical approach which allows the use of known optimization procedures.

Mobile communication in industrial automation systems is an increasing field of interest. Radio based fieldbus extensions are investigated in several projects. Approaches for CAN are also known. Nevertheless, the known solutions are still far from becoming a standard. This paper provides an overview of the necessary technical and economical preconditions of a radio based CAN standard. The standard can follow several objectives concerning the mobility, flexibility or network topology which are discussed. The technical problems of a radio based CAN standard are shown in this paper. Consequences for the level of specification as well as solutions which could be the basis of a future standard are also introduced.

For many users and suppliers CAN is the first choice for drive communication – due to its reliability, efficiency and flexibility paired with low hardware costs. CANopen provides a synchronisation mechanism, which uses the cyclic transmission of a SNYC message. However, the medium access method of CAN cannot guarantee absolute deterministic data delivery. Therefore specifically designed drive fieldbus systems had to be used for applications which require high precision drive synchronisation such as printing ma- chines, machine tools, packaging machines or robots. The deterministic behaviour of the CANopen SYNC telegram is limited to one frame length and may jitter with 130?s at 1 Mbit/s. This paper introduces a synchronisation method that uses the standard CANopen SYNC but achieves distributed simultaneous drive control which jitters less than 2 ?s. A phase locked loop mechanism that tolerates the jitter of a single SYNC frame is superimposed and provides the timing information for the position or velocity control data. The bus system capacity is discussed for various applications and it is shown that CAN and CANopen is suitable even for demanding real-time requirements.

We describe an optimization of the CAN physical layer as well as the CANopen application layer for use as an internal bus in a line of modularized laboratory instruments. Modifications and extensions are described for the pin assignments, Default Connection Set, Emergency Object, and the Device Profile to better support the requirements of our hardware. We also present a method that facilitates updating a module’s firmware via CANopen.

In this paper a novel wire concept is presented that increases the dependability of a distributed communication system in a major way. It tolerates and can still provide full functionality in presence of one single fault of several types, such as short/open circuit, nodes that fail uncontrolled, so-called babbling idiots and other bus failures. The concept utilizes a bus structure where the wire is divided into a plurality of sections. These sections are then interconnected to form an annular unit, ring, by means of a special module, REDCAN module. Each module comprises of a relay unit and logic, by which these can be coordinated with other circuits with the same functionality along the wire to define the left and right end of the wire to form a real broadcast bus. This is done by the individual circuit that decides to terminate the wire, one or two ends, or not at all – a transparent mode. The paper presents two fault recovery techniques. The first is currently implemented in a CAN kingdom system, where the master controls the set-up of the broadcast bus. However, an algorithm that can be utilized by a fully distributed system e.g. CAN, is presented. The concept is furthermore intended to be protocol independent, and therefore the system should be useful for many existing embedded communication systems.

This paper presents the design and use of a gateway module, GateKeeper, for automotive applications. GateKeeper translates messages between various speed CAN buses, running from 83.3Kbps to 500Kbps, and a J1850 bus operating at 10.4Kbps. The hardware portion of the paper describes the processor selection and overall electrical design. The software development environment is discussed along with message translation methods. A description of the use of the J2190 protocol to enable and disable each individual CAN and J1850 message is also provided. An example application of GateKeeper is presented.

ecause of the ever-increasing demand for information exchange in modern vehicles; for example the rain sensor needs to communicate to the dashboard control module, the air conditioning system has to talk to the seat module, the steering assist module wants to exchange information with the vehicle dynamics system, and the door electronics require communication to the vehicle alarm system; conventional parallel interfaces between the various control modules producing a wire harness as thick as your arm are no longer viable from an economic and technical point of view. In order to prevent this, the automotive industry and all European companies have decided to implement data communications using the serial 2-wire CAN (Controller Area Network) bus. Infineon Technologies AG recognised this trend and soon developed micro controller with an implemented CAN protocol machine on the market. The “Automotive Power“ department at Infineon Technologies AG began development of bus transceivers about 4 years ago. These transceivers are the link between the protocol unit (e.g. the CAN controller) and the physical transmission medium (bus cable). But more than that, the transceivers have additional tasks. On the one hand transceiver works as line driver to provide the required current to transmit the message threw the physical network, because in larger networks driver currents up to several tenth mA are required. Secondly the transceiver has to detect several bus failures (e.g. shorts) as well as interference pulses which can influence the CAN message coming from external sources are masked out to ensure communication (fault tolerant low speed CAN as well as the new high speed CAN transceiver generation). But the most important task of a bus transceiver is to protect the micro controller against external influences by de-coupling the micro controller from the harsh signals or high voltage spikes which can occur on the bus lines.

This article compares CAN with TTCAN (Time Triggered CAN) by hand of their abil- ity to react to asynchronous external events. For the evaluation the method ’Distinct- ness of Reaction’ is utilized which is based on an orthogonal Walsh correlation. The method measures the average latency response time and the jitter when reacting to asyn- chronous external events. Furthermore, the measuring procedure yields the ’frequency response’ of the communication system which allows the detection of its characteristic properties. Based on the results, a discussion is carried out which enables the derivation of interesting clues in order to plan and optimize time triggered systems.

Besides the well established event triggered bus protocols (such as, for instance, the CAN bus protocol) recently the demand for time triggered communication systems has intensified. In order to accommodate demand, an extension of the CAN bus protocol to TTCAN (Time Triggered CAN) has been specified in ISO 11898-4. In the meantime also a silicon implementation of TTCAN is available. Since there are no TTCAN compliant sensors and ECUs so far, for an initial examination an intelligent CAN/TTCAN gateway has been developed. In this way a laboratory style migration of a distributed control system which actually was developed around the CAN bus to its time triggered version TTCAN easily succeed. This migration is carried out here exemplarily by means of a vehicle dynamics control concept. Furthermore, the article gives some remarks concerning the synchronization of the sensors and the task management with the bus cycle.

The Controller Area Network is widely used as fieldbus in many distributed control systems. In addition to control information, a voice communication running on the same bus may have several advantages. This paper deals with an efficient implementation of a voice channel over an already designed CAN network. In particular, the solutions to minimize the band occupation and to cope with the large variability of the time taken to transmit a CAN message are described. A proof-of-concept demonstrator, consisting of two CAN stations provided with audio capabilities, has been realized and tested in an existing distributed control system designed and installed in a high-end motorcycle. Finally, in order to fully demonstrate the feasibility and effectiveness of our approach, the system performance under several bus load conditions has been characterized.

"""In citric fruits conservation and maturation systems it is very important to have faithful information about certain parameters that indicate the fruit state, and that allow to take the appropriate proofreaders actions in order to achieve an optimum controlled fruit maturation. In front of the rudimentary control systems that are being used at the present time, the Fault Tolerant Systems Group of the Polytechnic University of Valencia together with POLARIS TECHNOLOGY S.L company, have developed a new distributed control system based on CAN and Internet networks that allows a remote pursuit and control in real time of these processes. In each cold store, there are a strategically distributed set of sensors and actuators that are interconnected by means of a CAN network. One node centralizes the information, so that after its filtrate and storage is overturned on a backbone CAN network that interconnects all cold stores with a PC in charge of carrying out a second treatment and storage of the information and its diffusion to Internet. Finally, each user (authenticated by means of a security system) can be connected to his installation via an Internet connection or using a GPRS or WAP mobile telephone, to see the process evolution or to modify the parameters of each cold store. This system is completely operative and it has been already installed in different companies of several countries, obtaining very interesting results."""

Due to the increasing replacement of mechanical components by mechatronic modules and the demand of cross-linked sensor and control elements the effort of cabling and networking of individual components in MPVís is also increasing.

Powerline communications (PLC) stands for integrated transmission of energy and information using supply lines. The advantages of PLC are reduction of wiring, resulting in reduced costs, weight and use of space; reduction of complexity (of harness) providing a better handling capability. Further advantages are easy retrofitting/ retrofit procedure (aftermarket systems), possibility of parallel transmission of several services (e.g. diagnosis) and protocols and the possible usage as a redundant system for safety related applications. The transmission onto the powerline is based on carrier transmission technique in general.

Due to this advantages PLC is of high interest for an application as a CAN/ TTCAN physical layer. Some specifications and limitations are necessary for the use of PLC based on CAN. Caused by the CAN-specific access technique and the error detection/ recovery procedure usable transmission technique based on carrier frequency transmission technique is restricted. The core of the developed transceiver is the synchronization set to achieve the essential synchronization of each carrier. Using a developed algorithm the îsynchronizer-transceiverì can be determined in the "power on modus". CAN-PLC is a 100% CAN-compatible PLC-system. Only the physical layer has been changed (-> changing the transceiver). In the first step it is used for low speed CAN-applications (≤ 125 kbaud).

"""Although the intention of the new CIA-standard DSP 307 - “A framework for maritime electronics” - was to facilitate the interoperability of electronic equipment in maritime systems and to support the features required by these systems, the developed stan- dard is also of great interest for any application where highly reliable communication is required. In the paper, the required extensions of the CANopen standard such as redundant communication, flying master capability and maritime multiplexed PDOs will be ex- plained."""

The upcoming ISO11783 standard will be the preferred tractor Implement interface in the agricultural industry. Therefore the ISO11783 standard becomes a strategically important interface that has to be supported. The major tractor manufacturers as well as Implement suppliers already support ISO11783. Serial products will be available in the year 2004. So it is time to publish what the ISO11783 group worked out in a period of more than 10 years.

"""Electronic Data Sheets (EDS) do not always match the current specifications. The user of a CAN device has to check the EDS for syntax and for his application specific requirements. It can be a nuisance to do this manually, especially when the EDS changes often. Therefore, we implemented an automatic EDS Checker to perform this task and ensure the conformance of the EDS with standards and intern policies. In this paper we present this kind of software, an automatic EDS Checker. The program translates the EDS to an XML representation conforming to the Device Management Markup Language (DeMML). This is also the language for Device Investigator, our device monitoring tool. The actual checking is performed on this XML document. During the checking process corrections to the EDS, like creating unique parameters, can be applied. The individual tests are described in another XML document based on ComputeML. Predefined functions for comparison of strings and standard data types exist. Furthermore, basic tests can be aggregated to more complex ones. The defined tests are shown and a subset can be selected during an EDS check. We present a program which is on one hand easy to use with already defined tests and on the other hand tailor able to special needs."""

"""CANopen applications are often used inside machine solutions. This applications includes more and more control applications with time critical requirements. With this requirements real time OS are often the only way to fulfill this process requirements. Due to the fact that most of the readers know CANopen, this article is more focused to real time requirements. This article first provides a summary of the definition and requirements of real time OS and shows, based on a real project, how this features are used in the context with CANopen communication. The goal of this article is to give developers of CANopen some background based on an example how he can use this interesting features in his own projects"""

"""The paper presents different methods for observing, monitoring, parameterising and directly controlling CAN-based automation equipment using Internet technologies. Examples that are described are: a commercial industrial robot, a cartesian handling system, a workpiece separation unit and other CAN devices. Furthermore generic interfaces are presented to access CAN systems via the internet on CAN layer 2 and to access CANopen modules using the CANopen object dictionary / electronic data sheet. Since industrial equipment tend to be located behind firewalls, a method was developed and is described to get access to CAN even through firewalls and proxies. For demonstration purposes the described systems are online 7 days / 24 hours and can be accessed by everyone from all over the world."""

"""The CANopen application protocol is widely used in industrial machines. There are several companies providing source code that implements the protocol according to standards of the CiA and ISO EN 50325-4. The first steps into a new technology are very time consuming, especially when developing directly on the target hardware . Graphical tools can support development engineers during the creation of the object dictionary and produce the source definition in a programming language for the CANopen library as well as the EDS file and an HTML documentation. Star ting implementation on a desktop operating system like Windows or Linux, instead of starting directly on the target system is efficient because there is no need for flashing or downloading the firmware and debugging is easier. Por ting the application from the OS to the target hardware is done by only exchanging drivers and new compilation. The article shows that using a tool for defining the communication behaviour and object dictionary content at a high description level leads to dramatically reduced implementation effor t for CANopen devices."""

Simulation is useful on designing industrial communication systems and also a powerful teaching support tool. This work presents a CAN simulator system built on educational DSP hardware kits. Its design allows the study of network temporal behavior and its performance under a message workload. This is done by checking on the bus hardware several variable values for different bus parameter configurations. A CAN extension for time-triggered communication, the TTCAN bus, can also be simulated through a firmware upload on the simulator. The bus message set, the individual message specification and its timing requirements are downloaded to the hardware simulator through a PC connection. A software tool running on this PC records all timing information collected directly from the bus, on a bit time basis. This information can be used to evaluate specific message scheduling policies and network configurations for a message set. Results validation compares simulation values with those computed from an analytical model. Examples of simulations considering different bus window assignments and their effects over the message set schedulability are presented and discussed.

This presentation will describe the various development stages of the interface between the truck and the superstructure within the last two decades. Current problems with this interface will be explained and the requirements for an “ideal interface” will be defined. The requirements with respect to flexibility and real-time capability recommend the use of a field bus system. Reasons for choosing CANopen will be explained. This will be followed by information about the structuring of that CANopen Gateway standard, explaining also default communications and safety concept. In addition, the integration of the interface into the entire system of truck and trailer will be highlighted, special objects and mechanisms for superstructure manufacturers as well as the remaining open items. So it still needs to be clarified, which Truck manufacturers will support CANopen. They will commonly agree the mandatory objects, that will enable superstructures to develop their core functionality and modular extensions.

MultiCAN is a new CAN module, which is building up a bridge between TTCAN level 1 & 2 and normal CAN network. On one hand it has advanced features to mould the system matrix within the build-in scheduler on the other hand it has an improved list feature, a hardware gateway and additional features for CAN diagnostics. This paper compares and shows the improvement between the TwinCAN implementation and the new MultiCAN implementation. Finally it shows how to build up the system matrix and how to use the alternative message, in case the information for exclusive time windows is not ready.

With Layer Setting Services (LSS) it is possible to change the baudrate in CANopen networks. However, this mechanism fails in certain situations. This paper discusses an approach for an automatic baudrate detection in CANopen networks. As introduction the possible solutions to detect an unknown baudrate for CAN controllers (Software / Hardware) are presented. The paper will focus on situations where an automatic baudrate detection can fail (no traffic on the bus, error frames) and how to avoid these dead-locks.

"""Business buildings use doors with several electronic and electromechanical safety and security devices. These doors are for safety (escape route doors), doors for security areas, door interlock systems and automatic doors for convenience. The connection of various devices is today a challenge having as result the right door functionality. Some devices are also dependent from others, so the general function of the door depends also from the right coordination and control of those devices. Another problem is the wiring, some devices needs at least ten wires and if some of them are mounted on the door leaf, the problem is to carry the cable to the door frame. For those reasons, a door device bus network is necessary. In building automation (e.g. access control), the door can be seen as a black box with defined functionality. The configuration and extension of those devices to the door functionality will become to be easy and flexible using a bus network."""

A fault-tolerant clock synchronisation technique is presented. In a distributed system the discrepancy between a node’s view of current time and the rest of a system can cause critical deadlines to be missed. It may also be the cause of many unknown system errors. In fact, many real-time applications, such as redundancy management, synchronous data acquisition and simultaneous triggering of actuators at several nodes, are impossible without such a global reference time. DRTS Ltd have developed and have protected a software-based fault-tolerant clock synchronisation technique for broadcast networks such as CAN. It provides a predictable and reliable service that enables networked system synchronisation to micro-second precision using negligible network bandwidth.

Knorr-Bremse SfS GmbH is using CAN communication networks within railway applications: within trams, metros, locos or high speed trains. Typical components used within projects designed by Knorr-Bremse SfS GmbH are as follows: - Brake equipment (including brake handle, pneumatic panel, air supply) - Anti skid / anti slip system - Air conditioning system - Door control - Toilet control - Passenger information system. When starting the development of the CAN based electronic control system – ESRA (Electronic System for Railway Application) - a central electronic microprocessor system was used. The most significant advantages of the CAN based system are to decrease the costs for complex harness, to get more flexibility and to reach a higher EMI immunity. Up to now about 250 different projects have been equipped with ESRA technology, over all more than 100.000 boards with CAN interface are in service. Within the new CAN based system a well defined set of different standard board types has been defined, communicating by CAN communication. According to the project specific requirements a set of standard boards can be chosen to fulfil the project specification. Different control system architectures exist, all based on CAN. First steps in development have been to realise a “central” multi controller system using CAN for communication. All boards are physically placed inside a rack. Next steps were to connect two racks by an external CAN communication and to connect a remote MMI by CAN to the control system. Actual systems are designed to have a decentralised architecture. Knorr-Bremse SfS GmbH is using a proprietary CAN protocol, but similar to CANopen standard. In the CAN network Knorr-Bremse SfS GmbH is using the 11 bit identifier only, the bus rate is 250 kbit/s. In typical project environment a high electromagnetic influence exist. Due to this fact and according to required norms and standards a high level EMC qualification is done with all electronic equipment. The ESRA control system is able to interface communication systems based on CANopen standard by a gateway. Future concepts will strongly continue the development to more decentralisation. New steps of development will define decentralised functions combining mechanics and electronics to be mounted in the place the function is needed (next to bogie, etc.).

There are numerous applications of CAN carrying real time data. However CAN is still not become popular for carrying voice streams data. This paper delves on the possibility of transmitting voice streams over CAN. A detail analysis of various CODEC algorithms such as G.726, G.729 and G.711 shows how effectively CAN bandwidth can be used for voice transmission. The solution is realized with a specially suited proprietary protocol for Voice data. This paper gives the findings on following: CODEC suitable for voice communication over CAN, MIPS and memory requirements, effective CAN bus lengths, CAN bus loads and bandwidth calculations, buffer management, Quality of Service (QoS), assignment of CAN message identifiers.

Safety networks have emerged, which allow control system developers to replace hardwired safety chains with communication networks. Typically using industry standard networks for the base services, these safety networks add additional services to transport data with high integrity. Unfortunately the user must change their approach when going from one network or media to another. This paper presents a scalable, network independent approach to safety network design, where the safety services are described in a well defined layer, allowing the network to be changed without impacting the user’s approach to safety. This approach also enables the routing of safety data, allowing the user to create end to end safety chains across multiple links without being forced to difficult to manage gateways.

"""Prioritizing tasks in Hard-Real-Time Systems is a problem belonging to NP-hard class. Scheduling and resource allocation in real-time systems are difficult problems due to the timing constraints of the tasks involved. Scheduling policies in hard real-time systems need to ensure that tasks will meet their deadlines under all circumstances, even in the presence of faults. This work presents techniques to enhance the fault tolerance capability of multiprocessor hard real-time systems, in the presence of transient and permanent faults. As a special case, in the present paper we propose a new method to obtain a high level of fault-tolerance in the CAN bus by incorporating time redundancy and task schedulability tests, which may be used concurrently with processor redundancy and any other hardware redundancy."""

"""The growing acceptance of opportunity charging batteries while they remain in the electric vehicle made the development of a standard means of communicating the battery’s characteristics to the charger increasingly important. This paper gives some background information on why such a standard is desirable, and how CANopen provides the necessary framework for the standard. This paper also presents an implementation of the CANopen battery profile highlighting the battery module as well as the charger module."""

This paper presents a general purpose CPU with CAN bus controller designed to work in space and hostile environments where the effects of ionizing particles are relevant. Special design techniques and redundancy protect the internal registers and the memory cells - both internal and external - from Single Event Upset, with minimal impact on the performances and without using a radiation hardness technologic process for the chip. Moreover, an embedded In Circuit Emulator helps to develop and debug the software applications.

"""In the last years Ethernet has found widespread use and acceptance in office communications. Today it is readily available in almost every single personal computer for very low cost. With the growth of Ethernet based networks within offices the desire to connect to the field bus dominated production floor has grown as well. There are many different motivations for this desire, e.g. to monitor production flow and machines over short and medium distances or to enable the use of readily available hard- and software to name a few. The following paper will describe CANeye, a low cost embedded web server that is able to connect to CAN. CANeyes position and abilities within the network and an introduction to its hard- and software structure will be covered."""

"""PROFInet is an international standard for Ethernet-based industrial communication systems. It considers the integration of fieldbus systems, such as CANopen, which is well established in the field level of industrial automation. In the paper the different concepts of the PROFInet model are introduced. In particular the so called migration concept is explained, which deals with the possibility to integrate fieldbus systems into the PROFInet environment using a so called Proxy device. For CANopen the architecture of such a Proxy is described and the relation to the CANopen model elements is discussed. Finally an implementation concept of a CANopen Proxy with static CANopen device assignment is presented."""

"""Unlike most other fieldbus systems, CANopen provides many degrees of freedom to configure the communication behaviour of the network. Product manuals rarely describe simple paths to achieve the optimal configuration. Network analysis tools generate a lot of data that has to be interpreted by CANopen experts. Most CANopen users have difficulties to configure their network smartly and quickly and end up with sub-optimal setups. The paper first briefly explains the various configuration possibilities and shows the optimisation targets, depending on the application requirements. The influence of the parameters on reaction time, determinism and bus load is shown. Then a configuration guideline for CANopen networks is introduced, which allows one to optimize the network step by step using simple indicators."""

"""There are applications, where both maximum available bandwidth and reliability are needed. In those applications many issues - like effects of harsh environment, power supply, network length, available bandwidth, bus load, bus topology - must be taken into account to meet the requirements. There are different solutions to build CAN-networks and every solution has it's own benefits and drawbacks. The packet structure of CAN frames causes most of the limitations, when compared i.e. with Ethernet. Especially with high bit rates, up to 1 Mb/s, those limitations force to very careful network design. This paper will present, that in all selections of networking solutions must be done by taking into account the requirements of the application. Bus, star and tree topologies are examined with active and passive HUBs, repeaters and switches and many pitfalls are found and analyzed. In high speed CAN-networks, inter-segment routing has been found to be one of the most reliable implementation in complex systems. Based on the comparisons can be stated, that the most general solution for combining high-speed CAN-segments, which also meets standards, is to use switches with fully isolated CAN-interfaces. Those systems are electrically reliable, easy to assemble and terminate and maintain over system's life cycle."""

The current EDSs in use for DeviceNet are very versatile tools to configure slave de- vices, but they have certain shortcomings when modular devices are to be configured, specifically when it comes to determining the I/O sizes of the device to be configured and working with parameters in the modular section of the device. Using modular EDSs as already defined in the CIP common spec [1] in conjunction with a suitable software configuration tool opens up a whole scope of new capabilities. This paper describes several enhancements for EDSs including the concept of modular EDSs in a step by step approach, explaining the required and optional keywords in the set of EDSs required to describe a modular device and how these keywords interact. First, the concept of an assembly is introduced and it is shown how this assembly can be used in EDSs. In the next section, a set of minimum functionality modular EDSs (I/O only) is explained while the following section expands their functionality by adding configurable parameters in the modular parts of the device. Present and future capa- bilities of this concept are then discussed and how they can be applied to modular devices and even to devices that at first do not appear to be modular. Furthermore, the paper details the object and functionality enhancements required in a device to benefit from this concept. It also presents several sample EDSs and how they are used by the configuration tool.

This article describes the properties and possible applications of the „CANopen Safety Chip (CSC)“ in safety related devices. The object being described is a chip, partially certified by TU?V, which has met all the requirements of the IEC61508 standard up to SIL3 (safety integrity level). With the implementation of the CSC in safety related systems, a considerable reduction in costs for development and certification is achieved. Time to market is reduced noticeably. The structures of the CSC and the safety related permanent firmware are described here as well. Examples are shown to demonstrate possible applications. For example, the CSC assumes all control and monitoring functions in simple fail safe sensor/actuator systems. In complex devices (such as safety light curtains, drives) it can be integrated as a communication interface. There is a function and data interface available to serve as an interface to the application. This allows the user to access the CANopen functions, safety relevant data and the Object Dictionary. The user-oriented programmability of the CSC facilitates flexible implementation in various application environments.

New applications require more complex and sophisticated sensors to be connected to modern robot controls. Some tasks even need sensor based online generation or manipulation of robot motion in realtime. Increasingly personal computers are used for processing sensor signals and calculating control algorithms. This paper shows the design and implementation of a universal CAN based connection between a personal computer and a robot control, which was given the name SpeedFace. The link is very flexible and operates in synchrony with the interpolation cycle of the robot. It was developed as a basis and toolkit for experts to program new sensor supported robot applications.

IEEE 1451 specifies smart sensor function and connectivity to networks. This marks an evolution from central system control by a master processor with “dumb” nodes to distributed control networks of “smart” sensors. Controller Area Network (CAN) is a multi-master protocol designed for communications in real-time, distributed control systems. Therefore, it is logical that CAN be used to network smart sensors in these systems. The move to IEEE 1451 smart sensor nodes in distributed control systems with CAN connectivity increases the complexity and therefore size and cost per node. To address these size and cost issues, mixed-signal microcontrollers are now offered that integrate a CAN controller, non-volatile memory, and quality analog data converters. Such devices can offer integration of IEEE 1451 functions for smart sensor “plug and play” connectivity to controller area networks. Integration makes distributed control networks feasible.

This paper aims to give a general description of a Bridge designed to transparently interconnect a cloud of MilCAN [1] segments using a high-speed backbone such as Ethernet. MilCAN is a protocol developed under the auspices of the International High Speed Data Bus User’s group in order to cover the requirements for military Vetronics systems, providing deterministic and redundant communication between MilCAN nodes. With the constant increase of embedded devices within a vehicle the need for interconnection clashes with the speed limits of available backbone protocols. The VSI-Bridge is a software-based Bridge with routing capabilities (BRouter) developed to connect a MilCAN segment to high-speed complex protocols used as backbones. The target was to offload non-critical traffic from the embedded network to the backbone, thus reducing the load.

There is a need to control some discrete outputs and monitor status inputs on each RF Switch module, in a network of up to 3000 such modules, using low-cost CAN based solution.

Since 1996 NEC provides CAN interfaces. The DCAN is a single channel interface and the FCAN offers up to 5 independent channels with a focus on supporting gateway applications. These are well-established macros used in all areas of the automotive field. The successor macro AFCAN (advanced FullCAN) is designated to replace all existing CAN macros of NEC on all CPU platforms in order to provide a single architecture for the customer. It will help reduce the cost for maintaining many different S/W drivers. This has been recognised as a strong request from car manufacturers. Along with this strategic concept, NEC introduces new technical features while keeping the highly accepted features of the current FCAN. The frequent tasks like receiving and transmitting messages are now supported by separate “History Lists” that speed up these processes and provide to keep track on the sequence of messages without any CPU burden. Further the AFCAN features an “Automatic Block Transfer” mode with programmable delay in between those transmitted messages. The AFCAN carries 32 buffers per channel (available since b/o 2003). First products with 48 buffers and 16 buffers per channel are scheduled for e/o 2003. A derivative of the 48-buffer version features an integrated listen only channel in order to support monitoring of other CAN channels for diagnostic purposes.

Modern vehicles for public transport, manufactured by Vossloh Kiepe, formerly KIEPE Elektrik, have comprised CAN-based networks for control purposes since 1995. The CANopen protocol for can-based networks was introduced at Vossloh Kiepe six years ago. As a first step only the network-management and the process data objects were used. All vehicle control commands are transmitted via these objects. The master supervises the presence of all slaves by using the node-guarding mechanism. A special Process Data Object announces the state of the network. This interaction between master and slaves guarantees the detection of a faulty control unit within a time less than 1.5s. Important signals are additionally protected by a combination of time-outs, checksums and hard-wired signals, respectively. Service Data Objects have been implemented in the most recent vehicles for diagnostic and maintenance purposes. Energy consumption and event records, for example, are transmitted via Service Data Objects within the vehicle.

In order to standardize network system applications independently of the device im- plementation it is necessary to introduce the concept of virtual device interfaces. Sev- eral CANopen application profiles using the concept of virtual devices will be intro- duced briefly. In particular, there are methods how to define virtual device interfaces and how to describe a default PDO communication scheme allowing peer-to-peer data transmission. Hints are given on how to overcome the limitations regarding the num- ber PDOs and object dictionary entries.

"""Distributed control systems are widely used in today's even more complex technologies. Usually they are built on networks basis, where the nodes belongs to heterogeneous networks. Due to their specific advantages, CAN and LonWorks networks became de facto standard in different, often overlapping areas in industry, science and many others. The common operation of CAN and LonWorks devices involves however sustained high speed communication, transferring data in differing formats, with different data rates and using network's specific communication medias. These particular conditions require an appropriate protocol and physical link converter - a CAN-to-LonWorks gateway, in order to satisfy the requirements of both networks and to combine additional functions to control the direction and the amount of the transferred data, information updating, data integrity etc. A powerful gateway proposed in this paper is designed using In Application reprogrammables PSD components, poviding for flexible functionality, small size, low power consumption and low cost - all the qualities of prime importance. It is structured as two independent CAN and LonWorks nodes, each one running in its own network on peer-to-peer basis. Internally, they communicate via high speed Dual Port RAM, used as postbox, without need of any kind of software or hardware synchronization."""

As Tele-robotics continuously receives industrial attention, an embedded CANopen Master Stack, accessible via the Internet, is proposed. A configurable real-time operating system permits multi-threaded development whilst PLD technology ensures system evolution. The impact thread prioritization has on system performance is investigated, whilst initial design considerations are also presented.

Both CAN- and Ethernet-based networks are widely deployed in millions of nodes and applications world-wide. CAN was initialy developed for automotive and is nowadays very popular in the automation industry, too. For many years, Ethernet based networks are used in automation on higher levels. Due to newly developed real-time protocol extensions, this IT network technology becomes more and more popular on sensor and actuator level as well. CANopen is one of the most extensive selection of industrially applied device and application profiles. So far it was only used on CAN bus systems. With the growing demand for Ethernet on machine level, it was logical to integrate CANopen with Ethernet protocols in general and real-time Ethernet in particular

Distributed embedded systems that require real-time performance need a network capable of deterministic access delay. CAN is one such network that became widespread in recent years due to its electrical robustness, low price, and priority- based access control. However, its use in safety-critical applications has been controversial mainly due to dependability limitations that arise from its bus topology, e.g. the existence of many possible points of failure. In this paper we propose and present a star topology that exhibits improved fault diagnosis and isolation mechanisms with respect to other commercially available hubs. Our hub1 is fully compatible with existing CAN controllers but requires double links. The paper presents a prototype implementation configurable with 4 to 16 ports, describes its architecture and presents some performance results.

"""In this paper we propose a Hardware-in-the-Loop (HIL) approach to implement a preliminary architecture for force-feedback control in steer-by-wire (SBW) applications. A brushless DC motor (BLDC) is used as force feedback actuator. The determination of the position of the BLDC rotor plays a key role in the control algorithm. To obtain a reliable rotor position a classic triple static redundancy (TMR) is implemented. The position signals from the encoder integrated on the motor are computed in three different ways: using a 8-bit microcontroller, a 16-bit microcontroller, and, last, using the software module integrated in a virtual hardware development tool. The virtual hardware platform operates as voter, too. The position is the output of the voting algorithm and it is sent to the 16-bit platform that controls the motor and provides the correct output PWM signals. The communication between virtual hardware and real hardware uses CAN bus. The bus is monitored by a dedicated development tool. Steer-by-wire is a safety critical application and therefore requires time-triggered protocols. In this preliminary architecture a dedicated network has been implemented and therefore the disadvantages of the event-triggered protocol are considerably reduced. Experiments at different baudrates confirm that the voting algorithm produces correct results also in case of failure in one of the modules of the TMR architecture and it is not conditioned by bus loads. This means that the torque control algorithm of the BLDC motor can generate on the steering wheel (directly connected to the motor) a drive feeling like the one produced by a traditional steering system also in this fail- mode."""

A new communications system based on CAN is presented in this work. This system has been implemented to interconnect the different devices that compose a mobile robot, able to operate in environments with elevated electromagnetic noise, being even tolerant to sabotages provoked by means of high electromagnetic fields. The system is based on a shielded communications hub, that interconnects diverse nodes by means of CAN. On the other hand, the point to point communication between each node and the hub is carried out by means of economic optical fiber. With this approach all robot devices are connected by means of CAN, although a optical fiber arrives to each device. In this manner, the total immunity to the electromagnetic noise that the optical fiber transmission presents has been added to all the advantages of a system interconnected by means of CAN. The communications system has been installed in the mobile robot obtaining highly satisfactory experimental results.

The approach to both the architecture and the underlying technologies of a highly distributed systems platform for home and building automation is presented here. This concept is based on the capability to integrate a number of deeply embedded devices that share information among themselves and act as a single system, extracting knowledge from the data collected at the various locations and using this information to intelligently react to events and circumstances in the surrounding area, so as to economically provide comfort, safety and security to people working or living in that controlled environment. Special emphasis is put on the human interfacing to technology, by lifting up the traditional focus from the level of applications to that of services, therefore aiming at serving user's needs, but relieving them from low-level platform concerns. Middleware is used to address the issue of development barriers for services, firstly by providing means for graphical programming in order to rapidly create in-house living scenarios (i.e., complex applications, involving different, interacting variables and conditions) by simply drawing a block diagram that, with recourse to a library of pre-constructed models, addresses the various scattered units and invokes the respective local actions. Units in the system are of two different kinds, as they fit in electrical switchboards (where are concentrated the protective devices to power circuits) or, alternatively, are dispersed throughout the buildings, in relatively larger quantities. The former being integrated over CANbus, and the latter over a wireless cluster tree network based on IEEE 802.15.4 (ZigBee) technology, a unified approach to high-level remote procedure calls was attempted, thus encompassing both wired and wireless networks, which, being based on CANopen high-level protocol, allows a more effective co-operating service-computing platform.

This paper aims at defining an interface for the CAN data-link layer that both fits in well with the IEEE Std 1003.1 socket paradigm, and allows the user to access the full range of capabilities implemented by CAN interface controllers. At the same time, this paper also attempts to set up a set of specifications and guidelines for the actual implemen- tation of the proposed interface.

This paper will discuss the experiences and challenges with the implementation of up- integrated CAN transceivers found on system-basis chips (SBCs) for the automotive market segment. These SBCs exist in an extremely harsh environment, factors such as system interoperatibility, enhanced electrostatic protection, and electromagnetic interference need to be understood and designed in the integrated component to help reduce issues at system level. This is further complicated as the needs for up- integration forces a less than idea silicon process selection to maintain cost goals for the SBC. Detailed discussion of lessons learned include the silicon process development of ESD robust structures at the device level using a lateral-DMOS silicon controller reticifier; the addition of clamp structures to protect the device during short circuit conditions when a CAN choke is used; the influence of fault protection structures on the robustness of the receiver to electromagnetic interference during direct power injection testing; the future market trends for system-on-a-chip development and the impact of process selection to ensure the feasibility of an up- integrated transceiver; and system power up/down issues to minimize bus distrubances. The paper will conclude with future challenges related to up-integrated CAN transceivers.

Interoperability between CANopen devices is universally desired by most CANopen device integrators and other users. To this end, the CiA has defined a CANopen Conformance Test which checks EDS files and the devices for adherence to CiA specifications. However, these checks are against static requirements, implying that 2 devices which pass the Conformance Test may still not be able to actually interoperate. The CANopen protocol deliberately does not prescribe the dynamic timing parameters needed for true device interoperability, as different applications have differing requirements. Recognizing this fact, this paper does not set out to prescribe such specifications. Instead, building on TR 308, this paper describes a standard set of time value measurement definitions and a means for sharing these dynamic values between CANopen devices which provides a user with a means of quickly assessing interoperability & compatibility.

"""The Office of Research and Development of the Federal Railroad Administration (FRA) is sponsoring a revenue service demonstration of Advanced Train Systems featuring new technologies for improving safety and efficiency in freight train operations. The project, which commenced in 1999, is part of the Rolling Stock Program Element in FRA’s Five-Year Strategic Plan for Railroad Research, Development and Demonstrations. The demonstration system, referred to as the On-Board Monitoring and Control System (OBMCS), features an integrated package of sensors and actuators for monitoring and controlling mechanical components on freight trains. The OBMCS includes sensors to monitor bearings, wheels, brakes and trucks and actuators (referred to as advanced components) for remotely controlling parking brakes, angle cocks, cut levers and a cushion unit lockout system to eliminate slack. The demonstration of the OBMCS with advanced components will commence in 2005. An open system architecture based on CAN technology provides the framework for integration and control of the advanced components. The CAN bus network is also employed to monitor bearing temperatures and the status of brake piston travel sensors. A communication protocol based on a subset of CANopen Draft Standards DS301 and DS401 has been developed to provide a standard architecture for integration of sensors and actuators into the OBMCS."""

Development and verification of in-vehicle networks include multiple design layers. These layers include the logical layer represented by the software application, the associated data link layer, and the physical connection layer containing bus interfaces, wires, and termination. Verification of these systems in the early stages of the design process (before a physical network is available for testing) has become a critical need. As a result, the need to simulate these designs at all their levels of complexity has become critically important. In-vehicle networks can be simulated on many different abstraction levels using various model levels and modeling technologies. Early in the development process, analyses can be performed without having available any detailed models from the chip manufacturer or component supplier. Later in the development process, more accurate models can be integrated into the simulation process, including those provided by suppliers and chip manufacturers. This paper demonstrates a portion of the development and verification process of the physical layer of an in-vehicle CAN Bus at Volkswagen using the Saber simulation environment. This paper also demonstrates integrating portions of the logical layer into the simulation so both logical and physical layers can be simulated together.

"""In-system programming (ISP) of flash memory in an embedded microcontroller is the state-of- the-art method for updating program code and application parameters This paper gives some background information on why a standard method for reprogramming via CAN bus is desirable, and how CANopen provides the necessary framework for it. This paper also presents an existing implementation of a CANopen bootloader. The CANopen bootloader is compatible with CiA standard DSP-302 which means that any master node or an SDO client or CANopen configuration tool running on a PC can update the firmware of such a node, using SDO write access to an Object Dictionary domain entry."""

Current problems with the interface between the truck and the superstructure will be explained and the requirements for an “ideal interface” will be defined. The requirements with respect to flexibility and real-time capability recommend the use of a field bus system. Reasons for choosing CANopen protocol will be explained. This will be followed by information about the structuring of the CANopen Truck Gateway standard, explaining also default communication and safety concept. In addition, the integration of the interface into the entire system of truck and trailer will be highlighted as well as special objects and mechanisms for superstructure manufacturers. Finally current activities with application specific associations are mentioned. Their focus is to ensure an application specific interface setup in an plug & play manner offering significant rationalisation.

Time-triggered CAN (TTCAN) combines the advantages of event- and time-triggered communication in order to fulfil the requirements of distributed real-time systems. Of crucial importance is thereby the generation of the communication schedule which should consider the demands of the time-triggered system on the one hand, while maintaining a good real-time performance for the event-triggered part of the system on the other. This paper deals with heuristic scheduling concepts for TTCAN networks and carries out a comparison by means of the above mentioned criteria. The suitability of the concepts is evaluated by laboratory measurements. The results enable the derivation of important clues in order to schedule TTCAN networks.

The media problem is one of the major causes of DeviceNet node failure in factory floor application; and one survey in a typical industrial application shows that a great percentage of DeviceNet system failure is caused by media problem. This paper presents an approach of designing DeviceNet media redundancy; this approach will improve the reliability of DeviceNet system; meanwhile, it is a simple and low cost solution that does not change current DeviceNet hardware and firmware.

The method of signal propagation analysis in the transmission lines of CAN-buses has been presented in the paper. Its aim is to determine and/or verify of the CAN controllers configuration parameters from the point of view of realistic conditions in the designed network which are often omitted in the standard calculation procedure. The adequate computer programs, to solve the transmission line equations in the area of assumptions, were elaborated. It allows to obtain the practically useful parameters like: characteristic line impedance, signal propagation times, voltage drops and ground potentials, etc, which, in turn, are selection base of right CAN controller sets. This paper contains the review of applied assumptions and examples resulted from the conducted investigations.

"""This paper proposes extending the high performance Network Processor (NP) architecture to meet cost/performance requirements of new emerging high speed and higher cost networks for the automation and automotive industries. The use of NP architectures for implementation of IDB-1394, MOST and Power Ethernet networks, which commonly embed CAN bus control elements, is proposed. The paper describes the implementation of a CAN enabled NP, incorporating a CAN co-processor within an Intel IXP NP hardware emulation system, and supporting the CANopen protocol. The proposed NP would enable packet transfer between CAN-bus and a range of existing NP communication protocols, including Ethernet, HSS, USB, PCI and UART."""

This paper presents a novel architecture and verification model of the CAN protocol controller for ASIC implementation. The key features of the proposed CAN controller are flexibility in terms of interfacing with host processors and smaller chip size. Also, the architecture is efficient for Intellectual Property (IP) reuse because of its flexibility and synthesis efficiency. For verification of the designed controller, we developed a verification model for fast verification during the design phase. The gate counts of the core logics in the proposed CAN controller are 3189 gates which are much smaller than other controllers. After successful verification, the CAN controller was fabricated by using 0.35_CMOS process.

CAN system designers are being challenged to meet stringent Electromagnetic Interference (EMI) and Electrostatic Discharge (ESD) standards while increasing reliability and reducing the size and cost of their products. To solve this dilemma, noise reduction techniques and bus protection devices can be implemented without significantly adding to the cost and complexity of the transceiver circuit.

"""This paper presents a cost effective CANopen implementation of a system to be de- ployed in an extreme environment exceeding MIL-STD operating temperature range of -55C to 125C. Applications such as Deep Oil Field exploration tools require robust electronic systems that can operate at 200C and beyond which very often results in the miniaturization of the electronics. To operate in this severe and noisy environ- ment, a CANopen network for inter-module communication was chosen. Contrary to a standard implementation, a CPU-less approach was selected where the entire CANopen stack is implemented in a Field Programmable Gate Array (FPGA). The FPGA is a System-on-Chip (SOC) integration where the CANopen stack is coupled with a CAN controller and peripheral logic for analog and digital I/Os. This CPU-less approach meets the size, cost, reliability, and power consumption requirements."""

"""Developing and testing of distributed embedded real-time control- systems is known to be very challenging due to the difficulties of de- bugging these systems in a target environment (e.g. due to weak moni- toring capabilities and lack of powerful debugging tools). The simulation technology described in this industrial experience paper is a toolbox aimed to improve the development and testing of distributed, CAN-based, embedded real-time control-systems. When using our technology, a complete control-system can be developed and tested without, or with only partial, access to target hardware. This is achieved by replacing target hardware dependent operations (e.g. device driver and operating system calls) with simulated equivalences that allow execution in a regular PC environment using regular PC pro- gramming tools. Thus, powerful PC tools for debugging, automated testing, fault injections, and dynamic modelling of the target machine, are made available for the embedded systems engineer. Complex dy- namic behaviours can be studied in the simulated environment, with- out access to the target hardware, e.g. allowing single stepping through scenarios. Simulating the complete system also facilitates customer tests and end-user evaluation of the system in an early phase of system devel- opment. It also shortens the turn around time for change, test, and evaluation, because development can be performed on a single PC in- stead of a full target system."""

The bit-stuffing mechanism utilised by CAN causes the message transmission time to become (in part) a complex function of the contents of the data fields. This variation in transmission times makes it difficult to predict the precise behaviour of real-time systems implemented using CAN. Previous work in our laboratory has led to the development of a software-based compensation method which significantly reduces the impact of CAN bit stuffing on message transmission times. In the present paper, we focus on the impact of bit stuffing on a system implemented using a “Shared- Clock” scheduling method. We use a detailed Hardware-in-the-Loop (HIL) testbed to explore the behaviour of an Adaptive Cruise Control (ACC) system for use in a passenger car. Through the use of the testbed, we present quantitative results which demonstrate the impact of variations in the message transmission times on the performance of the ACC system. We go on to demonstrate the improvement in performance which results when the previously-mentioned compensation technique is employed. Finally, the memory and CPU resources required to implement this compensation are discussed.

The CLAN intellectual property core is a CAN 2.0B controller developed at the Electronics and Telecommunications Department of the University of Aveiro, for research and educational purposes and in particular with the aim of providing the adequate hardware support to implement and validate higher layer protocols such as TTCAN or FTT-CAN. It was modeled at RTL level using the VHDL hardware description language, synthesized, implemented and tested on Xilinx FPGAs. However, the model is technology independent and can be synthesized for different implementation technologies from FPGAs to ASICs. The CLAN IP core fully implements the CAN 2.0B specification and it includes also a synchronous parallel microprocessor interface, interrupt generation logic and some advanced features, such as message filtering, single shot transmission and extended error logs and statistics. The data bus width can be 8, 16 or 32 bits wide. For applications where microprocessor interface is not needed or a different interface is required, the core internal module that implements the protocol can be used separately. The CLAN controller with microprocessor interface logic occupies about 30% of a Xilinx Spartan-IIE XC2S300E FPGA, corresponding to 100,000 equivalent logic gates, approximately. It was tested with other commercial controllers within a bus operating at 1Mbit/seg.

"""One of the challenges in today’s communication applications is that more and more different network technologies need to be interfaced to another. A machine might use an RS-485 or other general serial network and also requires access to a higher control level via networks such as CANopen. The interfacing between those networks is especially challenging if not only different communication technologies but also completely different network protocols are used. Gateways interfacing such different networks need to process data through all protocol layers – in each direction in and out of the gateway – making this a higher-end application in terms of MCU performance, memory requirements and software development. Interfacing between networks would greatly be simplified if the same network protocol would be used on the various communication technologies as illustrated by figure 1. Instead of complex gateways, simpler bridges could be used requiring far less resources and development work. ?One of the few network protocols truly open to multiple communication technologies and applications is CANopen. It was originally developed to operate on CAN, however it was always kept open enough to be used on multiple communication technologies and with any application. This paper and class examines the core features of CANopen and how they can be adopted to other communication technologies"""

"""This paper details the first implementation of MilCAN on a UK military vehicle. The UK Challenger 2 (CR2) Main Battle Tank manufactured by BAE Systems Land Systems has been updated to include improved Commander’s Situational Awareness (SA) with new technologies communicating over MilCAN. Situational Awareness is critical to any fighting force allowing Battlefield Commanders to make better tactical decisions in a reduced timeframe, whilst providing the Commander with mission planning capabilities such as generation and monitoring of orders, reports, overlays etc. Currently, command and control on the battlefield is based largely on manual processes for the monitoring and planning of operations. The introduction of the Platform Battlefield Information System Application (PBISA) System for CR2 interfaces with both new and legacy vehicle sub-systems and allows automation of many of the currently manual tasks. The MilCAN data bus provides the communication between several processing resources on the vehicle and presents the vehicle Commander with essential information. The MilCAN data bus also distributes accurate and up to date position data to both Commander and Driver at their respective displays in a simple and easy to read format."""

"""The Controller Area Network (CAN) has seen enormous success in automotive body and powertrain control systems, and in industrial automation systems using higher layer protocols such as DeviceNet and CANopen. Now, the CAN standard ISO11898 are being extended to Time Triggered CAN (TTCAN) to address the safety critical needs of first generation drive-by-wire systems. However, their successful development depends upon the availability of silicon and software support, and appropriate development & analysis tools. This paper outlines some of the exciting developments at Warwick Control Technologies which includes:- a) An implementation that can run deterministically at 60% bus loading at 1Mbit/s and 70% at 500Kbit/s (almost twice that of traditional automotive CAN systems), b) Interoperability testing with the Bosch c) Rapid control prototyping for a TTCAN Embedded Node, and d) TTCAN transmitter/fault injector tool."""

"""During the current development of a modular drivers desk for trains a major factor that has to be considered is the input and wiring of the control signals. There are up to about 45 controls situated over the complete desk. The CAN (open) Bus system was selected for this purpose in order to maintain a flexible approach with a minimum of costs . When considering railway applications it is very important that all the standards and specifications (EN50155 etc.) are complied with and that the system guarantees an extremely competent method of control signal transfer. The controls must provide a high availability so that failures very rarely cause a break down. The paper describes the principles behind a 2 channel CAN System with control input backup via the display terminals of the dashboard in the cab. The aim is to maintain control over the main important input functions despite failures."""

In every day R&D work employing network technologies like e.g. CAN proper shielding often is impossible as frequent adjustments and new configurations have to be applied to the systems and therefore the outer system surface has to be kept open. Therefore EMI problems are commonplace. This leads to the problem that a lot of effort is distracted from the development of the circuit itself and spent on dealing with the resulting CAN errors. A very cost efficient way to avoid such problems is to use a low-cost optical CAN. For this only the physical layer has to be changed and these changes are such that existing electrical CAN segments can be merged with the optical segments. In such a configuration the hub or switch which is needed for these star topologies must be suited for real-time error detection in optical segments to avoid the breakdown of the whole network. Also the hub or switch should be able to support real-time connection or disconnection of the node when CAN nodes are connected or disconnected to the network, to avoid bus conflicts with the other network sharing units. We have developed a low-cost optical CAN network and have successfully implemented it in a hybrid drivetrain testbed. The previous problems of destroyed CAN messages due to heavy EMI resulting from power electronics like DC/DC converters were solved. Electric network segments were merged with optical segments.

"""CANopen is a well proven, well established and very versatile Fieldbus technology, implemented in a large variety of devices. CAN unquestionably has distinct advan- tages just as low connection costs per device, true multi-master capability and out- standing error detection and handling features. However, for demanding applications like motion control or applications which require large network extension CAN is in- creasingly challenged by the upcoming industrial Ethernet technologies. It is shown that there is an Ethernet technology that retains CANopen to such a large extend, that even most of the CANopen communication protocol stack can be re-used. CANopen over EtherCAT features PDOs and SDOs as well as an Object Dictionary, the CANopen state machine and fully supports all CANopen device profiles. It is shown that EtherCAT provides a smooth migration path for CANopen devices towards the brave new world of Industrial Ethernet."""

"""Single-bus CANopen systems have not been enough for large systems, where CANopen allows use of existing tools and good selection of standardized components. Still CANopen documentation is single-bus oriented, but does not limit the systems into single bus level. Many things, like signal oriented communications model, support more complex systems. Typically there are more than enough maximum supported amount of nodes and COB-Ids but not enough transmission bandwidth to carry all signals of the system in the desired time windows. This paper presents one solution, where every bus is still 100% CANopen conformant. Dividing a large system into smaller subsystems makes it easier to schedule signals into PDOs, to monitor buses by keeping subsystem specific signals local to appropriate subsystem and to decrease the coverage of fatal bus errors. Special gateways are introduced for signals, SDO- and EMCY-protocol. Also protocols and services restricted into one hierarchy level and reasons for the restriction are explained. The biggest challenges are found in EMCY-protocol and signal scheduling over multiple independent bus segments. In those issues there are also the biggest risk for application dependencies. Hopefully this paper is a trigger for official documentation and advanced development of multilevel CANopen networking."""

"""The routing of messages across CIPTM1 networks (CIP = Common Industrial Protocol) is one of the most interesting features of CIP since it allows seamless transition of messages (connected and unconnected) between a DeviceNetTM2 network and other networks of the CIP family, a feature that is not found in any other industrial communication networks. This contribution explains the following details of the mechanics of the routing process for both connected and unconnected messages: • Explanation of the general principle of the routing process • The port object and port segments • Details of unconnected message routing • Details of connected message routing • Execution of the routing • Object addressing and object visibility within routers as seen from multiple networks • Route browsing through multiple networks • Details of the routing within DeviceNet • Route representation with Electronic Data Sheets (EDS) • Bridging into non-CIP networks (last hop) • Real-world example: Full details of a trace of explicit messaging The advantage of the described method is the fact that there is only one routing method within all CIP networks (DeviceNet, ControlNetTM3, EtherNet/IPTM4) and therefore, only minimal translation of messages is required."""

"""A UML based framework for the simulation of distributed systems of embedded control units (ECUs) has been developed by proTime. This framework generates at its runtime an executable model of a system, described by an editable system description. Thereby this simulated system can be used for tests and analysis. A basis for this UML based framework are executable models of different field busses. Currently models exists for CAN and FlexRay, Wakeup Line and a real-time control bus for simulation control purposes. These field bus models will be used (even simultaneously) to connect the modeled ECUs while the modeled system is under simulation. This UML based framework allows both the simulation of communication processes, and the simulation of functionality depending on these communication processes all with the correct timing. The main advantage of this UML based framework is the testability of communication dependant functionality like gateways, control loops and network management without an expensive test environment. The principal theme of this speech will be the CAN bus model, its integration into the runtime-created system model and the resulting (almost boundless) possibilities. Currently automotive systems are the focus of our modeling and simulation, but the applicability of this UML based framework is not restricted to these tasks."""

"""Bus architectures with up to five independent CAN channels are used in today's auto- motive and industrial control systems. Caused by the rising numbers of sensors, actu- ators and electronic control units over the last years, modern control concepts demand devices supporting cross-linking of these channels. This interconnection is realized with a CAN gateway that connects several CAN buses between sub networks at differ- ent speeds. Current gateway implementations are based on one of two concepts. The one concept is an application-specific multi-channel CAN controller with shared message object memory. This concept is inflexible regarding the gateway structure, especially the number of CAN channels, but it enables the transfer of messages between the net- works without causing a high load on the host CPU. The other concept is a set of single channel CAN controllers served by a message handling software on the host CPU. This implementation is more flexible regarding the gateway structure, but the load on the CPU depends on the combined bus traffic of all connected CAN networks. Starting from these two solutions, a new concept has been developed, combining the advan- tages of a flexible structure with a low CPU load. In this paper, the three concepts are compared and advantages/disadvantages are shown. In addition, problems in the design of gateways are discussed."""

"""Electronic network-centric devices are being widely used in military vehicles. The environments they operate are demanding and performance delivery is crucial under harsh conditions. Dictated by application needs, customised levels of configurability control and analysis are essential. The objectives of the work presented in this paper are to provide intelligent means of connectivity for integrating diverse network technologies, and tools for configuring and monitoring military vehicle electronic systems. Our investigation introduces the use of smart bridges that allow access to custom tools for reconfiguration and network information from the system. The target is to enhance the means of configuring these bridges, and to acquire customised diagnostics that potentially provide enhanced performance solutions. Experimental investigations utilizing MilCAN and Ethernet are being conducted, using a variety of different network topologies and configuration sets, to interconnect multiple MilCAN segments over an Ethernet backbone."""

In the past, CANopen networks were used mainly as stand-alone networks embedded in machines and deeply embedded in sub-systems. If required, non-standardized gateway devices realized the connection to higher-level Ethernet-based networks. In future applications, Ethernet-based networks also may be connected to higher-level CANopen integration networks. Besides hierarchical network architectures, there may be required non-hierarchical network architectures, too. The paper presents the cur- rent status of standardized CANopen gateways to Ethernet-based networks, and dis- cusses the requirements on further standardization activities.

This paper presents a sample design and implementation of a CAN/WLAN/CAN interworking system using Wireless Interworking Units (WIU) that are capable of connecting remote CAN 2.0A nodes over IEEE 802.11b WLAN. This provides a straightforward solution to extend the size of distributed area of CAN networks and enables the CAN networks to communicate with other LANs utilising a low cost technology with high data rates.

Use of embedded controls units is still increasing in embedded systems like automotive, trucks... The industry trend is to develop distributed architecture, using embedded networks like CAN bus technology to link all together more and more parts as Electronic Control Units and functions. At the same time, there is the need to connect more and more extra consumer electronics products (telematics and infotainment systems, fleet management systems, Pay As You Drive equipment, black box for insurance...) to the original distributed electronic architecture of these embedded systems. By this way, electronic devices can get access to a lot of information from the car and offer more powerful added value functionality’s within always limited costs. Unfortunately, systems makers don’t allow intrusive solutions for safety, reliability reasons and for maintaining integrity of their entire systems. So, at this moment, there is no reliable and no legal way to integrate consumer electronics devices without compromising the integrity of the vehicle’s electronic system in an existing platform in aftermarket. NSI offers one way to do it thanks to it’s CAN contactless technology. Such interface acts as a 100% spy and neutral solution. It extracts data’s from the embedded networks (such CAN bus or other) without any electrical contact to networks medium. In this way, it’s compliant to system makers requirements, waranty the original integrity of their electronic architecture. There are plenty of applications for such contacless interfacing technology: fleet management system, CAN spy analyser and tools, insurance spy equipments and other after market equipments. This paper presents the main characteristics of an innovative CAN contactless solution: Technical presentation of the CAN Contactless interface, Reliability of the solution and Examples of application.

At first glance all CAN modules are very similar, the only difference being the number of message buffers which are included in the implementation. Depending on the number of buffers the module is often referred to as FullCAN or BasicCAN. A FullCAN implementation normally has an array of message buffers that can be configured as Transmit (Tx) or Receive (Rx) whereas BasicCAN has a limited amount of Tx buffers and an Rx FIFO(s). However, there are several other key requirements for a CAN module that are important in the selection of the most suitable module for an application, as they can have a big impact on the efficiency of the software. This paper discusses the main functional requirements of a CAN module for the automotive market and explores different implementations of the key requirements. Specifically, it compares implementing the requirements within a standalone module with the alternative approach of using a simpler CAN macro in conjunction with other standard MCU resources, such as system RAM, co-processor and DMA, which are not dedicated to CAN.

The paper describes the work developing a service tool to be used together with CANopen-based system. It presents the thoughts and requirements before and during the development process. The service tool has the purpose to handle design, production and service/maintenance functions in an electrical vehicle. This includes functions like diagnostics, parameter setup, reports and software download. A presentation how it has been implemented to enable all the function for both advanced users and as a user-friendly tool for non-experienced CANopen-users is also included.

The protocol stack supporting CAN (which encapsulates the overlying layers in the OSI 7 – layer abstraction model) is commonly implemented in software possibly within an OS or a task scheduler framework. Implementation of the protocol stack in software imposes memory overheads and constrains message handling when the bus is heavily loaded. Attempts to improve message handling capacity often culminate in esoteric, ROM – intensive filtering mechanisms. This paper discusses implementation of the protocol stack in an FPGA/ CPLD based platform using examples based on J1939. This results in cleaner isolation of reusable IP for the protocol stack, preserves provisions to tailor it without being limited by resources on the micro, and obviates the need of a CAN interface on the micro. Also, the paper identifies the challenges and tradeoffs involved in having this kind of a hybrid system with the user application executing off a micro, and the protocol stack realized in hardware, focusing on three key areas – time to market, rework in migrating from proven software based protocol stacks, and cost implications.

The implementation of an efficient real time networking with Controller Area Network (CAN) for distributed real time control in Hybrid Electric Vehicle (HEV) is presented. HEVs are the present potential choice for environmental friendly public transportation systems. Their safety and functionality can be improved and many value added features can be easily incorporated with CAN based distributed control. In HEV different electrical systems are functionally interconnected, requiring exchange of information accurately in real time within defined communication latency. The CAN controller reduces communications burden on the host CPU, thus allows to run its algorithms for better real time power train control. The differential physical layer improves data exchange integrity under EMI from power switching systems in this application. The implementation methodologies for TI TMS320F2406 Digital Signal Processor and PIC18F4480 Micro controller based hardware with inbuilt CAN controllers are highlighted. An efficient mailbox filter configuration and message distribution scheme in different control modules in HEV as well as state machine for minimum boot-up process for CANopen protocol in master and slave nodes are detailed.

CANopen continues to gain acceptance as a robust protocol for use in a variety of industries and applications. As this expansion occurs into new applications, the general-purpose I/O devices required by these applications are starting to push up against the limits of the CANopen Device Profile that describes them – CiA 401. In this paper, the author proposes some improvements to this venerable standard which will allow for a whole new generation of I/O devices to take full advantage of the CANopen protocol, without being unduly constrained by vestiges of the first generation which may no longer be needed. Changes to default PDO mapping, harmonizing the current behavior differences between analog and digital devices, and making sense of the Device Type object are all examined.

Communication protocols have traditionally been classified as time-triggered or event- triggered. A lot of efforts have been made to develop new protocols for control systems, e.g., LIN, TTP, TTCAN and FlexRay. The focus has rather been on the communication than on the system leading to systems designed for the communication. A system needs different types of communication in different situations. The communication has to handle time scheduled as well as sequence scheduled and event triggered messages simultaneously in an efficient controller system. CAN is the almost perfect protocol for this task. The Start of Frame ( S O F ) is well suited for synchronizing applications. Synchronized applications produce synchronized messages. By moving the timing from the communication layer to the application layer (where it belongs), CAN turns into the preferable protocol for time-triggered systems as it provides not only a robust communication during normal conditions but also during emergency situations. Unscheduable events as well as global clock failures can be handled in a predictable way.

The use of CAN with J1939 or CANopen based higher layers leads to cost efficient and flexible solutions, but together with a high increase of the electronics’ complexity. An additional complication is the typical approach of distributed development between OEMs and several suppliers. The consequence has to be a systematic improvement of the development process. Project risks are to be reduced by taking testability as a design requirement and by performing the appropriate tests in the very early project phases. This paper discusses concepts combining system prototyping with test case generation along the V-model.

Classic architectures of aircraft systems contain equipments using interfaces with digital, analogue or discrete signals. The electrical network to interface the equipments varies between the applications. Some equipment requires a dedicated power supply and provides information on an analogue current loop, while others use proprietary digital busses or discrete I/Os for information exchange. CAN initially was developed for use in the automotive industry, but is nowadays being used in an increasing number of applications. One of these areas is aviation, where CAN in the past 5 years has grown from being an exotic newcomer to an established and widely accepted solution. Within the Fire Protection System on an Airbus, smoke detectors are installed in various areas overall in the pressurized zones of the aircraft like lavatories, equipment bays and cargo compartments. As the CAN bus defines only layers 1 and 2 of the OSI communication model, additional higher layer features are necessary to achieve the level of operational assurance required for a safety critical application, namely fire protection on an aircraft. This paper is particularly focused on the development of a safety critical CAN bus network with strict configuration control of smoke detectors in the scope of an aircraft application. International airworthiness authorities in 2003 approved the application in the frame of the Airbus A318 Type certification.

Testing CAN applications requires complex test systems. Several interfaces are tested simultaneously in real-time conditions. Some components might not yet be available leertaste anzeigen and must be simulated. The simulation must be as straightforward as possible – otherwise, precious time is lost in testing the simulation rather than the real system. While specialized hardware test tools exist that cover some of these requirements, they usually do not support persistent archiving and test management. .faust is a fully configurable automatic software test system that combines aspects of quality assurance (version management, audit trails, user management,...) with requirements for real-time tests of multiple interfaces and/or components. Its kernel contains basic functions to test standard hardware protocols (CAN Bus, CANopen, LIN, Ethernet etc.), which are completed by a set of parameters describing the particularities of the component under test. A powerful scripting language offers the possibility to send, receive and process complex data or events to test diverse software interfaces and/or CAN-Bus protocols. Error situations and missing components can be simulated. Test data and results are stored in an Oracle database. In this paper we will present this tool that has been specifically designed for tests of embedded software in highly complex, safety-critical environment.

Usually gateway configurations have been based on non-standardized description formats. Unfortunately data exchange between different formats is inherently error prone and time consuming. A common description format was necessary and is found in the Field Bus Exchange Format. FIBEX is an XML-based file format, the upcoming standard for network configurations, which combines information about every aspect of a complete in-car network including controllers, channels, frames and signals. FIBEX is also the first standard to describe gateway configurations. Gateway implementations have proprietary internal formats in which they store their configuration data. Some routing information are stored as linked lists, while others are stored as executable code. An optimal gateway tool chain should be based on the FIBEX configuration data of all connected networks and translate the routing information directly into the internal format of the target implementation. The development of the tool chain at Bosch followed the development of a hardware-accelerated multi-protocol gateway. Currently the gateway connects FlexRay with CAN networks. Support for other protocols, like LIN and MOST, are planned. This paper describes the gateway hardware, gateway related enhancements to the FIBEX standard and the implementation of the tool chain to generate configuration images for the developed gateway.

AUTOSAR (AUTomotive Open System ARchitecture) aims to standardize interfaces between software application functions and further between application functions and basic software modules in ECUs (Electronic Control Unit). Independence from underlying hardware and this modular software design allows exchangeability of software functionalities amongst ECUs. The integration of functions from different suppliers is established through a virtual function bus. The mapping to a certain network topology (or to ECUs) is carried out after that step. In this paper configuration of a CAN stack and related basic software modules in system architecture development according to AUTOSAR is shown.

The paper deals with the several topics related to the development and production of the ultra low-floor tramcar, type TMK2200, for the city of Zagreb. During the development many electronic control units have been specified, designed and integrated into the vehicle. The communication between these control units is mostly based on CANopen. The reasons for selecting CANbus and CANopen application layer are discussed. Furthermore, several proprietary hardware and software solutions have been developed for this project. These solutions, among other, include redundant main vehicle control unit. The concept of this unit is presented, along with some details that increase vehicle reliability and availability. Finally, some experience facts and possible future improvements are also pointed out.

The development of simple CANopen devices up to complex systems requires exact planning and preparation. Planning and concrete realization depend each other to the extent that the selection of communication services has an effect on the performance of the assigned hardware and vice versa. The use of a prototype system enables early recognition and avoidance of bottlenecks or errors in the system. This leads to shorter development times by avoiding erroneous development and undiscovered problems in the network design. This article shows different approaches to construction, use and feasibility of prototype systems. Attention is drawn to to the scalability of the system and reuse of code from the prototypes for the target platform. In particular the codevelopment of Master/Slave applications are taken into consideration.

Time triggered network technologies are now entering into automotive electronic architecture designs. At the same time the number of ECUs integrated within a vehicle is growing, mostly integrated using CAN technology. Control applications on the next generation of vehicles will utilise LIN, CAN and FlexRay network technologies. A signal representing a real world physical quantity such as engine speed may traverse across several of these different networks. This paper investigates future requirements for the design of a vehicle’s electrical architecture. Particular attention is given to the mapping of CAN to time triggered protocols for efficient gateway design, Object Oriented Design and the XML expression of a vehicle electronic control system, and the optimisation of the electronics architecture in terms of cost and network utilisation.

A reliable communication of electrical fieldbus systems in EMI critical environments requires to precisely keep the specifications of the physical layer. Within R&D it is useful to change the topology of the connected nodes by demand and therefor fast. It is a key technology to use rapid prototyping systems to save development resources. Changes in the fieldbus topology should therefor prevent the developer of wasting time by arising communication problems. One solution for this problem could be the use of optical CAN networks. Unfortunately all components have to be prepared to be used in optical CAN networks. If only several nodes disturb the network communication by EMI problems electrical and optical mixed networks could provide a faster and cheaper solution. This paper focuses on optical and electrical mixed topologies for the CAN network. Changing the physical layer from an electrical to an optical layer means changing the topology from a bus to a star. A hub or switch becomes necessary and the support of point-2-point connections which could lead to a wire length amplification. To minimize the amount of wires a Switch, a Minibridge and a Multiplexer are proposed in this paper. The Switch supports point-2-point connections for optical nodes as well as an electrical uplink. The Minibridge connects electrical sub-segments to optical segments and supports bitwise arbitration. With the Minibridge and the Switch electrical and optical mixed bus-star-bus-topologies can be created for wire length reduction and easy connection of only electrical nodes to an optical network. The Multiplexer is necessary to merge different optical nodes to one optical network link which also leads to a wire length reduction. All proposed components support bitwise arbitration and are fully compatible to the CAN specification which is necessary for supporting electrical and optical mixed network topologies.

Research around CAN HUBs has been active, but presented solutions have not been compatible with standard high-speed physical layer. This paper introduces active HUB supporting ISO 11898-2 high-speed CAN physical layer and containing interface disable inputs for disconnection/reintegration logic introduced in recent publications. HUBs enable use of star topology, which can better fit into system’s physical structure, help avoiding uncontrolled ground currents and increase reliability. For HUB design and simulation, state-diagram based method is introduced with state- machine based behavioral CAN-bus simulation model. Timing constraints are introduced and transceiver loop-delay has found to be the most limiting parameter. Performance test computations has been verified with a prototype. The HUB supporting ISO 11898-2 physical layer can operate at any baud rate, but in real systems the HUB can operate at baud rates up to 800kbps. In addition to the interface- specific diagnostics features, HUB-based CAN-buses can ease systems designers by enabling star topology with improved tolerance against physical layer failures and without breaking the ISO 11898-2 physical layer standard.

In Automation Control Equipment, CANopen is more and more emerging because of its flexibility and openness. For larger systems one single CANopen network seems to be too restrictive. Multiple networks are the standard way of implementing such large networks, where CANopen takes the field oriented or machine oriented part. For communication over network borders, gateway functionality has already been defined in CiA309, in CiA400 and CiA446. This paper gives an overview on such functionality used in an I/O system and shows possible further evolution of gateway technology.

We present the novel concept CANopen.NET – In this concept we integrate Windows GUI-programming in .NET and control-applications based on CANopen. The integration is automated, thus no programming is needed. An increasing number of CANopen-based systems are equipped with Windows-based graphical user-interfaces (GUIs). Today, the .NET framework provides the most attractive solutions for design of GUIs both for Windows and WindowsCE based nodes. However, transferring information between the CANopen-domain (which is typically unmanaged code) and the .NET-domain (managed code) is non trivial. Traditional methods require handwritten pieces of code both in the managed and unmanaged domain for each signal (object-dictionary entry). Also, binding data values to graphical controls require hand written code. This means that adding or modifying signals to the system becomes tedious, error-prone and expensive.

Distributed embedded control systems for safety-critical applications require a high level of dependability. Despite the existence of communication protocols such as TTP or FlexRay specifically developed to provide that level of dependability, there has also been an increasing interest in CAN, given its low-cost, electrical robustness, good real-time properties and widespread use. However, the use of CAN in these applications has been controversial due to dependability limitations. To overcome some of those limitations, namely those arising from its non-redundant bus topology, we have proposed a replicated star topology, ReCANcentrate, which is transparent for any CAN-based application and protocol, and whose hubs incorporate the necessary fault-treatment and fault tolerance mechanisms. In this document we focus on how each node of ReCANcentrate manages the transmissions and the receptions on the replicated star, as well as how it tolerates faults.

Prototype level evaluation and verification of communication networks in various configurations over all possible corners, temperature ranges, etc. is a time consuming and expensive task. Moreover only certain corners coming from tolerances of all network parts (cables, common mode chokes, ESD protections) can be evaluated by measurements. Proper behavioral modeling of all network components including relevant corners conditions, allows handy verifications by simulation in early development stages and brings significant improvement in terms of cost and time to market for network designers. Modeling of a full network prior to prototyping can also serve as input for e.g. semiconductor manufactures to develop new transceivers based on simulation results. The paper deals with behavioral models of CAN bus transceivers. To allow various kinds of verification simulations in a reasonable CPU time starting from basic verifications up to detailed signal integrity analysis, thermal behavior, etc. a set of three behavioral models of a commercial CAN bus transceiver has been developed. The models were developed in VHDL AMS language with accuracy, speed and convergence trade-off being addressed. A network of CAN transceivers was simulated in various operating conditions and the results prove the effectiveness of chosen approach.

This paper describes CAN application in a modular robot system. RobMAT is made up of modules that form a new structure called molecule when they are joined together. Every molecule has a master module, which is in charge of receiving external message and retransmitting to the rest of the modules by CAN bus. The message contains all related information about movement control references, sensor data and module synchronization. CAN features allow faster transmission of up to 1Mbit/s. It is also flexible to connecting another CAN device. Such features make CAN appropriate for this application. Task performance using modular robots requires flawless communication among modulest herefore, synchronization is a key factor to take into account where in CAN plays an important role. The importance of synchronization requires a dedicated mailbox to manage it among the modules. Each module comes with a clock in order to process information by itself and correspondingly synchronize. Among the modules, one module has the master clock pulse that has to be transmitted to the rest of the modules of the molecule for readjustment of time. The experiments highlight the excellent performance of synchronization in crucial task.

The adoption of the CANOPEN fault tolerant standard by the Subsea Instrumentation Interface Standardisation (SIIS) Joint Industry Project was agreed by the SIIS panel in November 2005 . This paper presents the aims and background to the SIIS working groups decision to adopt CAN as an interface standard. For those with limited knowledge of subsea controls technology used in the offshore oil industry, the paper also provides an overview of the history and challenges of the application. The paper will then go on to discuss in more detail how CAN is being used in SIIS applications, it concludes by looking forward at planned future SIIS milestones.

The objective of this study was to develop an intelligent control system for hydraulic booms and other heavy machinery. An object oriented open source software development environment was utilized and the system was implemented using an embedded device with Linux as the operating system. The software was written in C and C++. Open standards and libraries, mainly the GNU C and C++ libraries, the POSIX standards and the CANopen communication protocol, were used. The CANopen protocol was modeled with C++ classes and presented by Unified Modeling Language (UML). A Domain-Specific Modeling language, specifically targeted at hydraulic booms, enables the initialization of the control software to different kinds of hydraulic booms and enables the modification of the control software using the concepts of the domain. By utilizing the scheduling features of the 2.6.-series Linux kernel, the control system achieved soft real-time behavior. The results were validated using both a simulated environment and a full-scale hydraulic boom.

During the last 10 years, CANopen became one of the most popular higher layer protocols for CAN-based networks. Compared with other higher layer protocols, the essential benefits of CANopen are its simplicity and flexibility which enables its use in a wide range of application areas. The versatility of CANopen is also reflected by the large number of available device, interface and application profiles. However, due to the increasing requirements of enlarging applications and systems, the maximum extension of CAN systems and the available data band width become serious limitations for the usage of CANopen in these applications. One of the most promising approaches to overcome these limitations is given by ETHERNET Powerlink, which conserves all the well appreciated CANopen mechanisms and profiles. Ethernet Powerlink is based on standard Ethernet but provides very high communication bandwith and hard real-time features. From the application point of view, there is no difference between CANopen and ETHERNET Powerlink concerning data representation, the object dictionary and the provided services. Therefore a migration becomes easy. Using gateways, CANopen and ETHERNET Powerlink systems can be interconnected smoothly.

Controller Area Network (CAN) is a popular and very well-known bus system, both in academia and in industry, initially targeted to automotive applications as a single digital bus to replace the wiring that were growing complexity, weight and cost with the advent of new automotive appliances. However, requirements have evolved and CAN’s dependability and bandwidth limitations led to the emergence of alternative networks such as FlexRay and TTP/C. Nevertheless, we believe that it is possible to improve CAN so it could fulfill contemporary requirements. This paper proposes the use of Flexible Time-Triggered CAN (FTT-CAN) to increase the available bandwidth while providing fault tolerance in CAN based systems with multiple buses. The architecture and flexibility of FTT based systems enables a tight yet flexible control of redundancy and bandwidth usage without increasing the complexity of the nodes. In this novel solution, a FTT-CAN Master controls the dispatching of messages among a set of independent buses. The Master can react online to bus failures switching the transmission of critical messages to a non-faulty bus, always keeping a pre- determined redundancy level.

TITAN©, TROJAN© & TERRIER© vehicles are the latest generation of Engineering Vehicles entering service with the British Army. TITAN© and TROJAN© are both based on the heavily armoured Challenger 2 hull having a large degree of commonality with their forebear and leant heavily on existing sub-assembly designs. CANBus was integrated into the vehicles’ electronic architecture to facilitate the trials programme. TERRIER© is an entirely new design and with it came the opportunity to integrate the latest technologies into a versatile, lightly armoured, highly manoeuvrable, tracked engineering vehicle. TERRIER© has a completely new and unique chassis and integrates COTS components over a wide range of functions. From the initial design CANBus was selected as the control bus architecture, with MilCAN as the preferred protocol. TERRIER© utilises multiple CANBus segments functionally segregated for Power Management, Command & Control, Special-to-Role and Automotive related operations. As an additional robustness measure, dual-redundant CANBus segments have been integrated in key areas.

This paper describes the B-Live® system targetted to automate house appliances for severely impaired people, in particular quadriplegic. This system has been developed at Micro I/O for enhancing the quality of life and the independence of its potential users. The envisaged application is the retrofitting of common dwellings. The B-Live system is described and details on its software, hardware and CAN-based communications architecture are provided. A survey of the supported appliances and interfaces is presented as well as a description of the B-live configuration and operation procedures. The adequacy of the B-Live system to improve the autonomy of the envisaged users was informally evaluated by C5 and C6 patients at a demonstration house located in the CMRRC Rovisco Pais, a rehabilitation center near Aveiro, in Portugal. The conclusion is that the system has a short learning curve and can cope with the requirements of its potential users. The use of CAN in this application opens the possibility to include safety critical real-time systems in the B- Live system. This is the case of the monitoring of the ventilator used for quadriplegic people that require breath assistance.

The new XML device descriptions for CANopen devices (CiA 311) substitute the existing electronic data sheets (EDS) and provide considerably more possibilities to describe CANopen devices with its application and its communication part in detail. This paper gives an overview of the XML device descriptions (XDD), illustrates the new possibilities in comparison to the EDS files according to CiA 306 and focuses on use cases and its advantages for CANopen device manufactures and system integrators e.g. for specification or testing of CANopen devices. Possible solutions for future trends like the description of finite state machines and dynamic behavior with constraints are discussed as well.

A personnel interlock system is a safety critical part in an accelerator. It switches off all relevant radiation sources in case of danger, e.g. klystrons, magnets and particle sources. The personnel interlock system at DESY is a logical circuit made up of relays that are hardwired to emergency off switches, access doors, safety key boxes, beam shutters and other dry contacts. The interlock software monitors each relay with a current monitor (optocoupler) and a bottom contact. To operate an accelerator, a warning procedure with optical and acoustical warnings is required. The interlock software controls the warning procedure by influencing the current path in the relay circuit. If any of the signals going into the relay circuit is missing, beam operation is denied or withdrawn. All safety critical paths are realized with the relays only, the interlock software must not have any safety critical tasks. Besides the safety critical aspect, personnel interlock systems must provide high availability to ensure long operation times. This applies especially to the interlock software and its components. CANopen based modules are used by the personnel interlock system to monitor the relays with a current monitor and a bottom contact. The personnel interlock software had to be overhauled from ground up. The new system had to be integrated into the existing interlock hardware infrastructure and makes use of standard CANopen means for configuration of CANopen modules (CiA-302-2) and process image processing (CiA-405). This paper discusses the used system architecture and aspects of integrating CANopen to Java.

The Gran Telescopio Canarias (GTC) is the most powerful ground telescope ever built. The segmented primary mirror has the largest collecting surface equivalent to one circular mirror of 10.4 meters. The control system (GCS) includes the hardware and software to control all the telescope subsystems, from the real time applications to the astronomer interfaces. Most of the real time GCS subsystems use CAN as the main control bus or to perform support functions. The main CAN application is the control of the primary mirror which is composed of 36 hexagonal segments. The GCS is responsible for making the 36 segments behave like a monolithic mirror. Three positioners per segment (total 108) will move it in tip/tilt and piston. Two position sensowrs (total 168) between adjacent segments will measure their relative displacement. This loop controls the positioners and reads the sensors at 200Hz over CAN buses. The figure of each segment is also actively controlled thanks to 6 actuators (total 216) that act on three whiffletrees attached to the back of a segment. This actuation is made at very low frequency. Finally, the temperature of each segment is measured in six points (total 216). Specific CANopen protocols where developed to control the positioners and read the edge sensors. CAN bus and CANopen protocols are also used to control and monitor several other subsystems of the GTC: tertiary mirror, dynamic counterweights, optics and filter wheels, temperature and humidity control loops, start up and stop systems, calibration lamps, etc.rimary Mirror Active Optic System.

Safety standards oblige to know the presence of people inside an escalator and moving walkways before changing its operation state. A photoelectric curtain based on emitter/receiver photocells is a good low cost solution. As a pair of emitter/receiver must be positioned every 30 cm along the escalator, the number of detectors increases greatly in long type conveyors and also increases the assembly and wiring cost. This paper shows a solution based in a CAN slave node network distributed along both balustrades of the conveyor (Figure 1). Every CAN slave node is based on a low cost CAN Input/Output Expander chip and controls a set of detectors (emitters or receivers). There is also a master CAN node based on a PIC microcontroller that treats all messages information received from the slave CAN nodes and controls a safety relay that informs to the motor drive controller.

To accentuate the growth of DeviceNet in the market place, a new media option has been released for DeviceNet. This low cost media provides a whole new approach to installing DeviceNet networks saving both time and money through Insulation Displacement Contact (IDC) technology. This paper will describe the technical merits of the media including topologies and connectorization options. In addition this paper will provide time studies on installation time savings over the traditional DeviceNet media options. Being that DeviceNet is based on CAN physical layer, this media can also apply to other powered CAN based networks using 4 or 5 conductors.

Tecnalia Automocion is working on an ECG sensor integrated into the steering wheel as one of several concepts following Ambient Intelligence (AmI) principles. This work is related to a previously developed prototype of a sensorized active headrest which was designed to maintain desired horizontal and vertical safety distances from the head. A networked solution, with smart sensors and actuators integrating the IEEE 1451 standard group, is being designed to be applied to the active headrest prototype and this ECG sensor. Following this standard, Tecnalia-Automocion has selected CANopen high level protocol to network this ECG sensor and obtain data about the car-driver, adding the plug & play feature with the mentioned IEEE 1451 standard.

The operational environment and physical conditions can affect significant embedded control networks to the point of failure. Fault tolerant systems usually require customized platforms which makes them not as flexible to use when only determinism is required rather than safety critical operation. In this paper, a Fault Tolerance layer is introduced that is designed as an add-on to the MilCAN standard, which offers an option to use off-the-self equipment achieving determinism and redundancy.

This paper introduces the new LSS Fastscan method that implements a generic and efficient scan cycle for non-configured devices. The LSS Fastscan was conceived for the CiA Application Profile 447 “car add-on devices” to simplify plug-and-play in the environment of taxis and other special vehicles. It was added to the CiA Document 305 “Layer Setting Services” and can thus be used by any CANopen implementation. Furthermore, the method is generic enough to also be used in CAN based systems using another higher-layer protocol.

This paper presents preliminary findings from research into a methodology for ascertaining nodal cost from the number of nodes and signal information. An estimation of nodal cost is useful in Design to Cost processes and can therefore be used to help partition CAN based systems using cost based decisions and help decide the number of networks and nodes. Published costing work and methodologies are reviewed. Then work on the estimation of microcontroller ROM and RAM requirements from the number of nodes and signals is presented and it is shown how this relates to nodal cost. The paper closes with a discussion on how this may fit into a Design to Cost process for distributed automotive electrical architecture design. This is shown for CAN and LIN based systems which are popular automotive networking technologies. However, the process discussed may also be useful for non-automotive distributed control systems.

CAN is the dominating network technology in automotive applications. Enhanced by the higher layer protocol CANopen it is a well established Fieldbus technology, im- plemented in a large variety of devices and systems. EtherCAT is an Industrial Ethernet technology which provides high end communication performance, flexible topology options and low system costs. In many applications, the distinct advantages of both networks have to be combined. With CAN/CANopen to EtherCAT gateways, this can be done efficiently, if certain design rules are followed. This paper discusses the requirements on such gateways from the application and from the device vendor point of view. Besides CANopen gateways, the special re- quirements of generic CAN to EtherCAT gateways as used e.g. in automotive test bed applications are considered. It is shown that CANopen protocols can be used to con- figure the gateway also from the EtherCAT side. Example implementations and their representation in software tools are shown as well as application examples. It is also shown that such gateways enable a smooth migration path from CANopen devices towards Industrial Ethernet.

Distributed control systems are ubiquitous nowadays, with applications ranging from vehicle to shop-floor control. With the increased penetration of control systems in all application, the need for reliable communication among the members of the system is more crucial than ever. Standard CAN bus networks already have embedded a mechanism to guarantee the provision of service in face of a one-wire fault in a two-wire differential cabling infrastructure. However there is no mechanism to guarantee continuity of service in the event of a two-wire fault. To achieve this, one needs spatial redundancy for the cabling infrastructure. However, the design and implementation of such kind of solutions places problems with a non-trivial solution, despite the end result is quite simple. This paper addresses how a FPGA-based solution may be used to enhance CAN network availability through the management of the several physical media which support a single, logical medium.

Perishable food products such as vegetables, fruit, meat or fish require refrigerated transports. As a consequence effective cold management is fundamental for maintaining the quality of these products along the supply chain. The use of standardized CAN technology can improve monitoring transports, ensuring the inter-operability of the system. A variety of sensors and actuators can be integrated in the CAN. Information provided by sensors has to be processed in order to check the adequate status of settings. In case of anomaly data, alarms should be triggered. Also actual devices for fleet management, such as Global Positioning System (GPS), tachograph and satellite communications, can be a part of whole system. And, in near future, more emergent technologies like Wireless Sensor Networks (WSN) or Radio-Frequency Identification (RFID) will be ready to implement in an on-line monitoring environment. Thus, the challenge today is interconnecting these heterogeneous systems and the harmonization of the different interfaces.

Complex machines use today control-systems consisting of multiple buses because any single bus can not support enough nodes. Moreover, any fatal failure in a single bus system will stop the whole system. With CAN, requirement of linear topology limits efficient networking in some systems. CAN-switch has successfully been used to solve those challenges. Benefits of a switch have been proved in real systems during last four years. This paper presents latest improvements in CAN-switch technology. Most significant improvement has been made in forwarding. A new state-of-the-art TX-buffering scheme has been adopted from Ethernet and ATM-switches. With the new buffering packet loss no more exists at full 1Mbps bit rate in 4-port switch. According to the measurements, forwarding delay remains constant for all CAN-IDs due to table-based forwarding rules. The forwarding delay of the switch has been significantly reduced from the delay of the first prototype. Another significant improvement is CANopen-based management interface. It enables seamless integration of CAN-switch into CANopen networks by offering object- dictionary based managing. Fault monitoring exceptions are provided as EMCY- objects and heartbeat producer enables existence monitoring of a switch. Support of existing CANopen design flow and network design tools has made use of a switch as easy as any other CANopen node.

In a standard DeviceNet system, reconnecting an existing slave device to a master can take between 2 and 10 seconds due to certain minimum wait times specified for the Master/Slave Connection Set. These wait times and the consequent safeguarding are acceptable for most DeviceNet systems where device replacement in a running system only occurs when a defective device needs to be replaced. However, such a long wait time is by far too much for highly dynamic systems with frequent device changes such as robots with exchangeable tools that contain active devices. To overcome this issue, the DeviceNet Quick Connect mechanism was invented. This mechanism bypasses the long wait times of standard devices and thus results in reconnect times of well under 1 second. This paper will discuss the standard wait times, explain the Quick Connect mechanisms and demonstrate the improvement in real applications.

The growing complexity of today’s system architectures is associated with an increase in the effort that must be invested in test specification, test creation and test execution during the development of such systems and system components. Test specifications should be available in early phases of the development process, e.g. after the system architecture has been created or during component design. This makes it possible to detect errors early and correct them cost-effectively. Device descriptions can be prepared for CANopen systems as early as after definition of the component architecture. Together with the system definition, the device descriptions form the basis for creating test specifications. They can be used to derive executable test sequences, which in turn can be executed in a suitable runtime environment.

CiA DS-405 defines a way to publish variables of IEC 61131-3 programmables CANOpen nodes through their Object Dictionary, using Dynamic Index Assignment defined in DS-302. Correspondence between IEC 61131-3 variables and Object Dictionary entries is let to the responsibility of the PLC manufacturer. IEC 61131-3 defines some Directly Represented Variables, specifying direction, size, and location of physical variables. In this representation, location is an arbitrary count of integers separated by dots. Again, correspondence between location of IEC 61131-3 and physical variables is manufacturer-specified. As a consequence, and despite of the standardization efforts of PLCopen and CiA, there is still no real interchangeability of PLC nodes in a CANopen network. This paper proposes a method for the PLC application writer to explicitly publish and subscribe to CanOpen remote variables with Directly Represented Variables location. As a complement to DS-405, it could suppress most network reconfiguration steps when moving PLC programs from one brand to another. Presented concepts and algorithms are already implemented in the Beremiz and CanFestival open source projects, and are publicly available.

Embedded systems are now-a-days complex distributed systems (e.g. automobiles, elevators, building climate control systems, and aircrafts) with various demands on networking capabilities. These Networked Control Systems are Distributed Control Systems (DCS) where controllers, sensors, actuators and other system components communicate over a network. It is easy to imagine that according to the high complexity of the networked electronic systems, the risk of failures of the system is increasing. So there is a need to provide high levels of reliability within the network. To accomplish this task a network management system is used. CANopen protocol is a networking system based on CAN serial bus. It has been widely applied into networked control systems. The CANopen networking functionality is implemented in one of the CAN nodes. This node is responsible for conducting networking functionality such as mode control, error control and configuration control. The network is vulnerable if this node fails. This paper presents a fault tolerant system, which deals with failure of so called Network Manager and sorting out this situation by providing a redundant node. The redundant node is provided with optional functionality of Network Management along with its original functionality of Slave Node.

The Stewart Platform is a well known and studied parallel robot. It is composed by an upper ring and six linear actuators. The actuators can be hydraulic, pneumatic or electrical, being the last used on applications where moderated forces and moments are required. In this paper a control of a Stewart Platform with electrical motors is described, the motors are regulated by CANopen based controllers. A CAN network is built to communicate and synchronize the motion of the six motors. A PC104 board and a Real Time Operating System (RTOS) are selected to create a fast and reliable CANopen master. The software running in the PC104 is developed from scratch however some basic features are ported from open-source software. The PC104 board is connected to a desktop PC through an Ethernet network, allowing a remote controlled system. The Stewart platform control is running on the desktop PC due to its high computational requirements.

Light electric vehicles (LEV) driven by battery-powered motors require embedded communication networks. In order to standardize the communication between the different devices, some suppliers and some vehicle manufacturers have selected the CANopen application layer. The paper discusses the technical and market requirements and the possible CANopen profile solutions.

Most standalone CAN controllers available today are connected to the host system by eight or sixteen bit wide parallel buses. Write and especially read accesses to such peripheral devices are very slow compared with the cycle time of modern CPU's. This paper discusses the resulting performance bottleneck and shows a solution, using a CAN controller implemented in an FPGA, that can use bus master DMA.

Different governments around the world are calling for massive reductions of CO2 emission. In the EU by the year 2020, the average CO2 emissions per passenger car should fall to 95 g/km. Hard measures and challenging technological advances are required. The imposed EU limits are not achievable only with the optimization of conventional technologies. New methods dealing with an efficient and flexible power management are an urgent need. Partial networking is one of these methods. It is intended to make it possible for a node or a sub-network to be woken individually by means of dedicated and predefined messages. When its tasks are not required it is in selective sleep mode. With this approach, a saving of almost one gram CO2 per km is a realistic estimation for a middle-range car. Since the beginning of 2010 a working group called SWITCH has been working to make partial networking for CAN bus systems an environmental and commercial success. The outcomes documents specified in the framework of this working group are currently in the ISO process. Different concepts for partial networking as well as the achievements and standardization activities taken over by the SWITCH group will be presented in this speech.

This paper describes the design, manufacturing and installation of a CAN bus Lamp control system that eventually consisted of 765 nodes running a customized protocol updating nodes at 24Hz. A second network, with 6 nodes running the CANopen protocol, was used for diagnostics and bus configuration. Each LED Lamp node has a single processor that controls 36 Red, Green, Blue and White LEDs. The application software, written in Delphi and running on a PC sends messages via USB to a control computer containing 5 CAN bus channels. The 5 CAN bus channels were further broken into 3 sets of 50 nodes using a CAN Bridge. Additionally, with a USB to CAN controller the CAN open link into the Bridges was used to monitor the status of each of the 15 groups of 50 CAN nodes.What made this project unique was the time frame from concept to the design, construction and installation of this one of a kind product. Some of the problems, included rainy weather, component and cable failures are discussed.

A steering control system based on CAN-bus technology was developed in accordance to safe operations for vessels on sea. With CAN-bus technology we reduced the efforts of cabling with highest reliability on sea. The paper describes the steering and navigation system of vessels with respect to automatic control. All data (reference values, measured values, alarm handling, configuration values) of a steering system with certain devices (e.g. Rudder, Feedback Unit, Gyro, Autopilot, etc.) are transmitted via CAN-Bus in real time. A short introduction explains the problems of steering vessels. A central component of the steering system is the autopilot. Its main task is to keep the ship on heading given by the helmsman or an Electronic Chart Display information system (ECDIS). The main part describes the design of the required controller. Closing the paper with measurement results of the autopilot demonstrate exemplary the safe operations.

CAN is one of the most successful wired serial data communication protocols both in terms of volumes and in terms of acceptance across industry branches considering the past twenty years. It is the predominant bus protocol in today’s and upcoming vehicles. This paper outlines protocol success factors, CAN protocol usage at GM/Opel, CAN benefits, and protocol improvement needs from an automaker point of view.

Motion control includes drives technologies and control systems with integrated software platforms. Currently, the drives are represented by pneumatic and electric technologies. A challenge for the suppliers of Motion Control solutions is to propose the common platform (hardware/software) which allows the easy use of pneumatic and electric drives. Example of this platform could be hybrid valve terminal where the coexistence of these two technologies was possible thanks to: - CAN bus used as the embedded backbone for communication with all elements of Motion Control system - Common Data Profile for pneumatic and electric drives

Since Linux 2.6.25 (issued 2008-04-17) the Linux mainline kernel supports the network protocol family PF_CAN providing standardized programming interfaces for CAN users and CAN driver developers. This paper provides an overview of the implemented technologies and challenges to integrate the Controller Area Network into a non-real-time multiuser/multitasking operating system. Due to the standardized network driver model for CAN hardware a wide range of different CAN controllers and System-on-Chip CAN IP cores are supported by Linux out-of-the-box. In opposite to usual embedded CAN ECUs the Linux networking system is designed to handle multiple CAN applications using multiple CAN busses at the same time. The integration of the CAN infrastructure into the networking stack allows to implement CAN-specific transport protocols like ISO 15765-2 or high-performance CAN frame gateways inside the operating system context. Finally the paper discusses solutions for expected prioritization issues when executing multiple CAN applications and summarizes requirements for Linux-preferred CAN controller concepts.

Ever increasing bandwidth requirements in automotive networks impede the applica- bility of CAN due to its bit rate limitation to 1 MBit/s. To close the gap between CAN and other protocols, we improve CAN in two ways: (i) support of bit rates > 1 MBit/s and (ii) support of payloads > 8 byte per frame. We achieve this with a new frame for- mat where we can switch inside the frame to a faster bit rate for (i) and use a different data length coding for (ii). This new protocol is called “CAN with Flexible Data-Rate” or CAN FD. CAN FD protocol controllers are also able to perform standard CAN com- munication. This allows to use CAN FD in specific operation modes, e.g. software- download at end-of-line programming, while other controllers that do not support CAN FD are kept in standby. This paper presents the CAN FD frame format with additional bits in the control field to enable the new options and the new CRC sequence to secure longer frames with the same Hamming distance as in the existing CAN protocol. The configuration options for the two bit rates are explained in detail. We provide measurements of the upper limits for the bit rate, using the first hardware implementation of a CAN FD protocol controller and standard CAN transceivers.

During recent years, the discussion about power saving had and has different aspects. One of them has been to save power in CAN applications. The mechanisms, which can be used either on physical layer or on the microcontroller, will be discussed within the article.

In this article, we present a new method for describing CANopen network topology. A new format using GraphML, an XML-based graph format, is introduced. By using a subset of GraphML along with CANopen-specific new elements and attributes, topology of single as well as multiple CANopen networks can be captured in a well established graph format with existing tool support. The new format is specified in a manner that allows CANopen design applications to adopt it while providing a mechanism for fallback in unsupported software. Methods for extending the format to contain other CAN- and CANopen-specific data as well as transforming the GraphML- based network structure to other formats are described. Finally, the implications of the introduced method and format are discussed.

During recent years, not only CAN and UART communication have been important for microcontrollers, also Ethernet was gaining importance. Therefore, microcontrollers for industrial application do not only need an intelligent CAN module, they also need smart ways of connecting to other protocol engines. This article shows one solution to do so.

One intriguing aspect of networked nodes is the option to allow their firmware to be remotely updated in the field. Some CANopen Device Profiles have even made this a requirement. The updating process in the target is handled by a dedicated piece of firmware, the CANopen bootloader. A failure of the bootloader can have severe consequences, from necessary power cycles over direct mechanical interaction with the device up to having to replace the node. For deeply embedded nodes that are out of reach, for example in deep-sea applications, such a failure can even be catastrophic. Therefore, in this crucial piece of software, security and reliability of operation deserves special consideration. Combined with resource constraints common in bootloaders, these unique requirements ask for a dedicated rather than a common off-the-shelf CANopen implementation. This paper discusses the security aspects of such an implementation in regards to software engineering, safe coding practices and operation flow.

SocketCAN, the official CAN API of the Linux kernel, has been included in the kernel more than 3 years ago. Meanwhile, the official Linux repository has device drivers for all major CAN chipsets used in various architectures and bus types. SocketCAN offers the user a multiuser capable as well as hardware independent socket-based API for CAN based communication and configuration. In this paper we will at first focus on motivating the socket based approach used in SocketCAN and continue with a discussion about its supporting and opposing arguments and current limitations especially in comparison with other available Linux CAN stacks. We proceed with a close look at the structure and duties of a generic CAN driver. The usage of the most widespread userspace protocol for sending and receiving raw CAN frames (SOCK_RAW) is illustrated with a small program. The paper concludes with some remarks on the outlook of upcoming contributions and enhancements such as an isotp and a J1939 protocol implementation.

This paper describes the development of a family of sub-fractional horse-power electric motors with integrated CANopen interface. The integration of motor and control unit makes elegant and compact drive solutions for numerous industrial applications possible. The drives decrease wiring effort in the system and space requirement in the electronics cabinet. Additionally, the integrated bus interface of these motors enables an efficient automatic final test in the motor production line without the need for cost intensive test stands.

In August, ETAS and Robert Bosch Engineering and Business Solutions (RBEI) jointly published BUSMASTER, a free open source PC software for the design, monitoring, analysis, and simulation of CAN bus systems. The software can be downloaded from rbei-etas.github.com/busmaster/. The current BUSMASTER version is based on the preceding software tool CANvas, conceptualized, designed and developed by RBEI. It offers import filters for network description files and simulation programs compliant with standard industry formats. For CAN connections, hardware from different vendors is supported. The BUSMASTER software project, sponsored by RBEI and ETAS, is open to contributions from research and industry. The software can be developed and managed with free software tools. Thanks to the modular architecture, third-party software developers can easily add new functions to the software. The license also permits the provision of proprietary add-ons, which can be dynamically linked to the open source core. The openness of the project managed by the sponsors provides for flexible modification and extensions regarding bus systems, protocols, and hardware interfaces. In addition, it will facilitate short cycles in the solution’s onward development.

This paper addresses the analysis of control performance for vehicle active suspension via Controller Area Network (CAN) based on full vehicle model. The dynamic model of the system is developed based on four sets of suspension which constitutes 14 state variables communicated through six CAN nodes. The Linear Quadratic Regulator (LQR) technique is used to reduce heave, pitch and roll variation to achieve desired performance of active suspension. The simulation work is performed by using Matlab/Simulink with TrueTime toolbox. Various system performances are analyzed by varying CAN data speed, CAN loss probability, nodes sampling time, clock drift and scheduling techniques. Based on the analysis, the setup of the proposed CAN network for the system meet the system requirements.

Use of Linux in embedded systems has become vastly popular. On hardware platforms, the ARM processor cores have a strong foothold. To address the needs of Linux-based embedded automation systems, Wapice has implemented custom high- performance CAN driver architecture. The Wapice Custom Can Driver (WCCD) is targeted for embedded Linux and optimized for ARM-based platforms. In this paper, we present our findings made during the development process and methods we used to optimize the driver performance. Performance measurements, comparing the effects of optimizations, are also presented. We discuss how CAN message buffering algorithms affect the bus performance, show how Linux kernel version affects the interrupt latencies, and present challenges related to SPI-based CAN transceiver chip usage. To evaluate our design, we present the performance of Wapice Custom CAN driver (CPU load, CANmsg/s) and compare it against SocketCAN and LinCAN implementations. We also show results of a brief study on porting WCCD to other processor platform. Based on the results, we conclude that WCCD is an extremely high-performance embedded Linux CAN driver which can match or outperform the compared existing implementations.

"The demands on the availability of data in the cabin and cockpit have been increasing in recent years. Right there is the application of new field bus systems. These must be suitable for the harsh environment in aircraft and therefore shown to be sufficiently robust. In the area of network based aircraft systems, the CAN-bus has emerged as a future technology. Through standardization, industrialization of that technology is now ahead for the aviation industry. In the Technical Working Group ARINC 825, in- dustry partners of the aircraft industry, led by the two largest aircraft manufacturers Airbus and Boeing, developed a standard that will change the interconnection of sys- tems in aircraft further. The standard describes guidelines and ""best practice"" to be observed by the system developers and the aircraft manufacturer for seamless inte- gration into the aircraft and smooth interaction of the equipment."

Nowadays we discover a changing focus at car development. To handle the growing system- and testing complexity, simulation comes to the fore. This process is supported by innumerable tools and methodologies with the goal to speed-up and simplify the development of new automobiles and technology. The tools are mostly highly specialized and dedicated only to a tiny area of the development process or on the other hand are such generic that they cannot be used without customization. In the area of subjects of C&S group and its customers it occurs very often, that the validation of real and simulation-based networks and components must be integrated into the development processes of the customer. The experience of C&S group in collaboration with its customers has shown, that the validation of simulation-based network descriptions gains more and more acceptance. Therefore C&S group has developed a new automation tool to validate network topologies, like they are used in automotive, avionics and industry areas, with the aid of a new model-based testing methodology. This paper shall present the new automation tool and shall generally enlighten the model-based testing methodology with practical examples.

TREPEL, the leading manufacturer in the cargo high loader market, introduced a new product line, the Challenger tractor. These new vehicles are able to handle pushback, maintenance towing and repositioning of any commercial aircraft, up to the new Airbus A380, and almost every military airplane. The Challenger fleet is designed to perform under tough working conditions as well as extreme climatic conditions. The ballasted version of Challenger 700 can handle weights up to 600 tons. Instead of usual controls and instruments, the dashboard is equipped with a Janz Tec panel-PC. This is the main control center of the tractor and the display of all relevant data provided by the internal CAN bus.

There is today more than 20 years of experience in automotive CAN applications, and CAN has certainly proven very successful as a robust, cost effective and all-around network technology. But the use of CAN in vehicles is evolving, in particular because of more complex and heterogeneous architectures with FlexRay or Ethernet networks, and because of recent needs like hybrid, electric propulsion or driver assistance that involves more stringent real-time constraints. Besides, there are other new requirements on CAN: more fine-grained ECU mode management for energy savings, multi-ECU splitted functions and huge software downloads. In parallel, safety issues request more and more mechanisms to protect against potential failures and provide end-to-end integrity. The development process is also evolving with the advent of multi- domain cooperation, Autosar, ISO2626-2 and the always shorter time-to-market requirements. In this landscape, CAN has now to be used at much higher bus load level than in the past, and there is less margin for error. What does it imply in terms of verification and validation? What are the characteristics of the communication stacks that should be paid attention to? This article is intended to shed some light and share our views on these issues.

Shortly after the Controller Area Network developed by Bosch was introduced in cars, it started to be used in industrial communication networks. The most successful Higher Layer Protocol which is based on CAN is still CANopen. CANopen tried as good as possible to use the technical parameters given by the underlying CAN chips. Now, after decades, Bosch has extended the CAN protocol to be much more faster. It seems to be possible to overcome the most criticized parameter in CANopen - bus speed and available bandwidth. The paper discusses the new opportunities for CANopen given by the »CAN with Flexible Data-Rate«.