Controller Area Network (CAN) - Electrical Engineering and ...

Controller area Network (CAN)EECS 461, Fall 2008 J. A. CookJ. S. Freudenberg1 IntroductionUp until now, we ve considered our embedded control system to be self-contained: an algorithm implementedin software resident on a single microprocessor, communicating with its environment through sensors andactuators via peripheral devices such as an analog-to-digital converter. In fact, many embedded systems aredistributed, consisting of multiple microprocessors communicating over one or more networks to accomplishshared tasks. For example, a modern automobile may have seventy or more microprocessors communicat-ing over several networks to manage entertainment and navigation functions, central locking mechanisms,lighting and other vehicle systems. Safety systems such as air bags employ dedicated high speed networkcommunication, as does powertrain control for communication between, for example, the engine and trans-mission controllers. Figure 1 illustrates some of the networks connecting automotive embedded systems[1, 2].

Node 1 loses arbitration Node 1 Node 3 Node 2 Node 2 loses arbitration Figure 3: CAN Arbitration: Node 3 has highest, and Node 1 the lowest, priority messages. Control and Data Fields The control field of the data frame consists of 6 bits (of which only the lower 4 are used) that indicate the amount of data in the message.

Tags:

  Controller, Network, Area, Done, Controller area network

Information

Related search queries