You might have missed seeing the family of Anybus-IC devices from HMS Industrial Networks. The company's modules give designers a simple way to connect equipment to several industrial-level communication networks or buses that include DeviceNet, Profibus, EtherNet/IP, Modbus-TCP, and Profinet. The company's latest module provides CANopen communications. The CANopen protocol runs on top of the basic Controller Area Network (CAN) protocol and helps ensure compatibility between industrial equipment from many manufacturers. For more information on CANopen, visit: www.can-cia.org/.

The Anybus-IC module contains a microprocessor, an integrated CAN controller, and a CANopen slave software stack. The 32-pin plug-in module (0.6-inch-wide DIP socket) includes all the needed analog and digital components, and isolated connections to the bus of choice. Engineering time costs money and a plug-in module that fits into a socket makes sense because you can interchange modules for different networks. The software drivers remain the same. You just add a different connector. The price for a single module is approximately $US 125.

The module acts like as a standard CANopen slave and supports Version 4 of the DS 301 profile. Nonmembers of the CAN in Automation organization can request a free download of the document, "CiA 301 DS V4.0.2 – CANopen application layer and communication profile," on the can-cia.org Web site noted above. The interface permits as many as 144 bytes of input data and 144 bytes of output data.

If you plan to use an Anybus-IC module or chip in a microcontroller-based design, you can connect the MCU to the module via a fast serial-TTL interface. The IC handles the entire CANopen protocol and offloads the microprocessor from all time-critical communication tasks. When designed into simple automation devices, developers can use an internal shift register to communicate with an Anybus-IC module.

For more information about the CANopen Anybus-IC module, visit: www.anybus.com/products/products.asp?PID=408&ProductType=Anybus-IC. From that page you can move on to obtain documents such as the 86-page "Design Guide Anybus" and the 37-page "Fieldbus Appendix Anybus-IC CANopen." The Web site also provides sample code you can use to control a module.

If you want to get a module powered and running quickly, you'll probably want the company's evaluation board (part no. 017499), which eliminates the need to wire-wrap or create a prototype board, which adds its own uncertainty. Find information about international sales offices on the HMS Industrial Networks web site: www.anybus.com/.

--Jon Titus