Controller Area Network (CAN)

Controller Area Network (CAN bus) is a standard serial communication protocol, meaning that its support of distributed real-time control and multiplexing allows for the interchange of information among the different components of a vehicle. The Classical CAN frame format allows bit rates up to 1 Mbit/s and payloads up to 8 byte per frame, but a newly introduced format, the CAN Flexible Data Rate Frame format, allows bit rates higher than and payloads higher and longer than these conventional values. While the CAN protocol was designed for and is still used primarily in road vehicles, the vehicle bus format has been incorporated into aircraft, aerospace, and railway systems.

CAN was developed in 1985 for in-vehicle networks as a replacement for the increasingly troublesome point-to-point wiring systems that were being used by automotive manufacturers to connect electronic vehicle components. Prior to this time, manufacturers had been incorporating more and more electronics into vehicles, resulting in bulky wire harnesses that proved to be both heavy and expensive. As an in-vehicle network, CAN quickly became a highly advantageous alternative, as it was not only high-integrity but also reduced wiring cost, complexity, and weight. After its adoption by the automotive industry, CAN became the focus of the ISO 11898 international standard in 1993.

CAN is a multi-master peer-to-peer network, in that each node (“assembly, linked to a communication network, capable of communicating across the network according to a communication protocol specification”) in the system is able to temporarily control the action of other nodes. When a CAN node is ready to transmit data, it checks to see if the bus is busy and then simply writes a CAN frame onto the network, giving bus access to the node with the greatest priority.

Read more at the ANSI Blog: https://blog.ansi.org/?p=7030

Learn more about The American National Standards Institute (ANSI) following this link.