Design Of Data Transport Module Based On CAN BUS

This thesis introduces the application of CAN Bus on the water level data acquisition and transport. The task comes from a real problem of water level controlled at Tang Gong Ta pump station, which is a water level controlling system for safe range between pool and electric moter. Can Bus is chosen here as a mean of data transport in this design because of cost and feature of Field-bus and it works well in practice now.The CAN module in central station which is mainly introduced will transmit instructions to other pump station based on received data from stations. User can input transmitted data and CAN node information from PC. The data information from PC's serial port will transport to single chip computer(SCC ) AT89C51 through MAX232 for electric level conversion. Firstly SCC needs to initialize CAN protocol chip SJA1000 correctly, then the data from SJA1000 will be output CAN Bus through driver 82C250. In receiving process, the node information concerned will be first transport to this node as above and then the data from this node will be sent back to host through CAN Bus. All the data is packed in a special way inside the SJA1000, and will be sent or received under pelican mode of CAN2.0B. The paper alsodescribes a method to realize the communication between PC and AT89C51 through Microsoft's MSComm. The serial port communication is programmed with DELPHI 7.0 and data transport with assemble language in the design.