CAN bus is one of the most widely used fieldbuses in the world. It was first introduced by the German Bosch company for the data communication protocol between the measurement and execution parts inside the car.
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The application of CAN bus ranges from high-speed network to low-cost multi-line network, and is widely used in the data communication between various detection and actuator in the control system. In the field of fieldbus, CAN bus has been widely supported by computer chip manufacturers, and they have launched microprocessor (MCU) chips directly with CAN interface. CAN is a multi-master mode serial communication bus, the basic design specification requires a high bit rate, high anti-electromagnetic interference, and can detect any errors. CAN network has the following characteristics:
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Any node on the network can actively send information to other nodes on the network at any time, regardless of master and slave. Using non-destructive bus arbitration technology, when two nodes transmit information to the network at the same time, the node with low priority stops the data transmission actively, while the node with high priority continues to transmit data without being affected.
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It has the function of point-to-point, point-to-multipoint and global broadcast transmission to receive data; Communication distance up to 10k(5kbps), communication rate up to 1Mbps(40m), the number of network nodes can actually reach 110, the number of effective bytes per frame is up to 8, so the transmission time is short, low probability of interference; The communication medium can use cheap twisted pair wire, no special requirements; Each frame information has CRC check and other error detection measures, the data error rate is very low, high reliability; When the transmission information error is serious, the node can automatically cut off its connection with the bus, so that other operations on the bus are not affected