The Controller Area Network (CAN) is a multi system capable network. This implies that data messages transmitted from any node on a CAN bus does not contain addresses of either the transmitting node, or of any intended receiving node. In a CAN network many short messages are broadcast to the entire network, which allows for data consistency in every node of the system.CAN can theoretically link up to 2032 devices (assuming one node with one identifier) on a single network. It offers high-speed communication, which allows real-time control. In addition, the error confinement and the error detection feature make it more reliable in noise critical environment.The content of the message is labeled by an identifier that is unique through out the network. All other nodes on the network receive the message and each performs an test on the identifier to determine if the message, and thus its content, is relevant to that particular node. If the message is relevant, it will be processed; otherwise it is ignored.
The CAN was optimized for systems that need to transmit and receive relatively small amounts of information (as compared to Ethernet or USB, which are designed to move much larger blocks of data) reliably to any or all other nodes on the network. Since the protocol is message-based, not address based, all messages on the bus receive every message and acknowledge every message, regardless of whether in needs the data or not. This allows the bus to operate in node-to-node or multicast messaging formats without having to send different types of messages.Fast, robust message transmission with fault confinement is also a big plus for CAN because faulty nodes will automatically drop off the bus not allowing any one node from bringing a network down. This effectively guarantees that bandwidth will always be available for critical messages to be transmitted. With all of these benefits built into the CAN protocol and its momentum will make other markets will begin to see and implement CAN into their systems.
