CiA® 443: CANopen profile for SIIS level-2 devices

The CiA 443 CANopen profile for SIIS level-2 devices covers all simple sensors, multi-functional meters, and valves used in so-called Christmas trees. The default physical layer is ISO 11898-3 compatible. The default bit-rate is 50 kbit/s. The CANopen node-ID is assigned by Layer Setting Services (LSS). The profile specifies a boot-loader mode, and the starting and stopping of application programs. Simple sensors include pressure, temperature, and position sensors as well as inclinometers. The profile also supports multi-phase flow, wet-gas, oil-in-water, and some other complex meters as well as dedicated detectors (e.g. PIG). There is no mapping defined for the four default TPDOs and RPDOs. The PDO communication parameters are pre-defined.

Offshore platforms are linked to subsea trees (nicknamed Christmas trees) comprising redundant controllers, different sensors, valves, and other equipment. These devices are on the ocean ground in depths up to several hundreds meter. They are connected by means of CANopen networks. The devices (also known as SIIS level-2 devices) comply to the CiA 443 profile, which was developed and is maintained in cooperation with this SIIS (Subsea Instrumentation Interface Standardization) group. SIIS level-1 specifies discrete analog interfaces and SIIS level-3 defines Ethernet interfaces.

The CiA 443 profile comprises interface specifications for simple pressure and temperature sensors as well as complex multi-purpose instruments such as multiphase flow meters. Subsea actuators defined in CiA 443 include simple valves and valve controller units. Support for Layer Setting Services as defined in CiA 305 is mandatory. It is recommended to support the optional LSS identify service.

After power-on, SIIS level-2 devices enter the boot-loader mode; application programs are not started automatically. In this mode, Heartbeat functionality is not switched on. The device waits for the start command given by the application manager. When an application program is started, the device first performs a local NMT reset node service. In this operation mode, Heartbeat functionality is mandatory. If all application programs are stopped, the device performs a local NMT reset node service and it falls back into boot-loader mode.

The specification of the SIIS level-2 application manager is not covered by this device profile. Often, two manager entities are integrated into the network providing NMT “flying” manager functionality as specified in CiA 302-2.

CANopen network linking several SIIS level-2 devices to the subsea control system, which communicates via CiA 309 with the off-shore platform control system

The CiA 443 profile includes several virtual devices, so that a SIIS level-2 device can provide a sub-layered network or serial links. It is so-to-speak a gateway and provides proxies for the connected functional elements (e.g. different sensors). This means, SIIS level-1 devices can be easily integrated into SIIS level-2 networks. Of course, the sub-layered network may also comply with CiA 443.

CANopen network linking several SIIS level-2 devices to the subsea control system, which communicates via CiA 309 with the off-shore platform control system

Two different physical layers are specified. Besides the low-power, fault-tolerant transceivers (compliant to ISO 11898-3) optionally high-speed transceivers (compliant to ISO 11898-2) are allowed. The default bit-rate is 50 kbit/s, a bit-rate of 125 kbit/s is required as well.

In CiA 443, the are following virtual devices specified:

  • Pressure sensors
  • Temperature sensors
  • Linear position sensors
  • Inclinometers
  • Multi-phase flow-meters
  • Wet-gas meters
  • Sand meters
  • Oil/gas meters
  • Single-phase meters
  • Water-cut meters
  • PIG detectors
  • Vibration monitors
  • Leakage detectors
  • Valve units
  • General analog inputs
  • Rotational position sensors
  • General digital inputs
  • General digital outputs
  • Corrosion/erosion sensors
  • Passive acoustic sensors
  • Chemical injection valve units

The SIIS group has organized SIIS level-2 plug fests, where the interoperability of CiA 443 compliant devices could be proven.

Title Details
CiA 443 version 4.0.0CANopen profile for SIIS level-2 devices
DescriptionThis document specifies the CANopen interface for SIIS level-2 devices. This includes instruments and actuators for subsea measurement systems. The specification of the SIIS level-2 application manager is not in the scope of this document.
DSP2.5 MiB2022-11-18Login