Can Bus In The Industrial Air-conditioning Control System Realization

CAN (Controller Area Network)is one of popular fieldbus at present. It have many advantages such as multimaster, high transmission speed, long distance, automatic solving bus competition, automatic retransmission, strong correcting ability and so on. It has been applied into process control, machine industry, robot, medical equipment and so on.This paper first introduces the development of CAN and content of this research and structure of this paper. Then papers describe the CAN protocol , compare 485 bus with CAN, give us a detailed description of message filtering and information frame. In the end, paper introduces the CAN node based on the industrial air controlling system and node design of hardware and software.The paper design different CAN node which can communicate each other in several modes. The node can be applied in control network which is composed of many special sites or industrial workshops. It has no effect on bus to adding or removing a bus node. According to customers' request, nodes can communicate in point-to-point mode, one-point-to-many mode, broadcast mode. The design of CAN node has reference value for common air conditioner design. The system can be monitored through personal computer which connected the CAN bus through special CAN device.