The Controller Area Network (CAN) is a robust serial communication bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. It was originally developed by Robert Bosch GmbH in the 1980s for in-vehicle networking in automobiles, but it has since become a popular standard in industrial automation, medical equipment, and other embedded systems.
The key features of CAN are its reliability and resilience to noise. It uses a differential signaling scheme on a twisted-pair cable, which makes it highly immune to the electromagnetic interference common in automotive and industrial environments. It is a message-based protocol, meaning messages are not sent from one specific node to another, but are broadcast onto the bus with an identifier. Each node on the network receives the message and decides whether it is relevant based on the identifier. This identifier also serves as the message's priority.
If two nodes try to transmit at the same time, the one with the higher priority (lower ID number) message automatically wins arbitration without any data being corrupted or lost. This non-destructive arbitration mechanism is crucial for real-time control systems where certain messages (like an emergency stop) must be processed immediately. For programmable power supplies used in automotive testing or industrial automation, a CAN interface allows for direct integration into the system's control network, enabling seamless communication with ECUs (Electronic Control Units) and PLCs (Programmable Logic Controllers).