Automotive and process control environments aren't the only homes for controller-area networking (CAN) these days. It can be found in everything from printers to robots.
Topping out at 1 MHz, CAN uses a differential bus architecture (Fig. 1). Its packet data size is only 8 bytes, but this is often more than enough for embedded applications. In fact, the identifier is frequently used to indicate an event or value when there are no data bytes. Multiple packets can be used to transmit blocks larger than 8 bytes.
The key to CAN is the transceiver (Fig. 2). It's typically implemented using bipolar technology to handle 12-kV ESD and provide thermal, short-circuit, and transient protection. This robustness can be quite useful in non-automotive environments as well.
Protocols have been built on CAN, including CANOpen. Supported by CAN in Automation (CiA), CANOpen's device profiles describe how a node operates. It also lets designers build their own nodes that work with nodes from different vendors. The CANOpen protocol is much simpler than TCP/IP, but it's ideal for sensor and control applications. It might be the right protocol for your next project.
