Laboratory testing machine
Source: CAN Newsletter March 2005
Medical testing laboratories must automate their test procedures in order to stay competitive and keep costs at bay. Drug and biotech companies do the same to speed up their development cycles. Automated material handling and storge systems for medical laboratories have become available to do just that. They contain trays for storing chemicals and test materials in temperature-controlled environments and handling systems for moving the trays to test areas where materials can be mixed automatically. The resulting mix is placed in test tubes or plates and is then either stored or transferred.
Necessary for such a system are two main parts: a database that provides information on where the materials are stored and that keeps a history of each individual test tube or plate, and a computer that controls all activities and movements.
Previously TekCel used a proprietary distributed servo controller with a multi-drop RS-485 network. The drive they chose for this solution provided a similar package size with more current capability, more robust CAN communication, and an operating temperature to suit the application. The CANopen network is used to control pneumatic valves and I/O modules that also use the CAN protocol. The drives are networked at a bit-rate of 500 kbit/s. The company decided to use CANopen because of its real-time capability. The drive implements the CANopen application layer (CiA 301) and the device profile for drives and motion control (CiA 402). One CANopen interface is installed along with one RS-232 interface. The drive is fully programmable with the company’s programming language. The drive provides 32 KiB memory. Using the company’s setup tool, users can perform drive setup, configuration, tuning, analysis and drive programming.
