Design And Implementation Of Distributed Temperature Acquisition System Based On CAN Bus

The rapid development of industry intelligence and networking technologies，makinghigher requirements for temperature sensors data acquisition on Industrial field.Acquisitionsystem not only to complete the multi-channel, high-precision data acquisition, but also canbe able to recombine acquisition data of subsystems real-time, to achieve the integration ofdistributed acquisition and control.Therefore, the design of distributed temperature systemwith high precision acquisition and good real-time is important.Object of this paper is measurement and control networksystem consists of twoacquisition units, interface repeater and test equipment. Mainly with mission requirements, onthe basis of CAN2.0B protocol, developed a simple and flexible user application layerprotocol to ensure the normal communication between network members. The desigen ofCAN bus interface communication module based on C8051F can send and receive CAN busdata. After discussion of the system acquisition mode,the final decision is to set up Ping/Pong cache and A/D acquisition uncontrolled by the command to improve real-time dataexchange. Through the optimization of acquisition module hardware circuit and theachievement of oversampling mean filter algorithm improved the accuracy of the systemacquisition. In addition, the program design of interface repeater ensure the reliability ofcommunication networks. When an acquisition node is failure,it does not affect thecommunication between the master node and other acquisition nodes. It can able torecombinant data of acquisition nodes, and complement data exchange via RS422interfaceand test equipment. The network can also access the CAN bus monitor module to obtainaccurate data and then analysis Sub-channel on PC or draw Waveform.Finally, the functional modules of the system was tested, the test results show that thesystem acquires high precision,CAN bus communication network is running well. The entire measurement network system perform stability and achieve the desired design goals.