Design Of Fieldbus Instrument Based On CAN Protocol

With developing and appearing of micro-electronics technology,Fieldbus technology has already attracted attention of instrument industry at home and abroad. CAN fieldbus is a technology which efficiently supports distributed real-time with a very high level of security,It attracted attention with a very high level of capability and a very high level of security and a very better of anti-jamming and a very fast of communication speed and a very low of maintenance cost and a particular design,It was regarded a fieldbus with expansibility. With rapid-developing of fieldbus technology,the traditional instrument will be affected,and it will be replaced with the instrument based on fieldbus. It is realistic meaning to research and develop instrument based on fieldbus.This paper analyzes and discusses capability and characteristic of fieldbus technology,and analyze and research CAN protocol of CAN fieldbus. The design of communication module and input instrument and output control instrument based on CAN field bus is discussed in detail.The circuit design of the CAN communication module based on SJA1000 CAN controller and double-port RAM IDT7007 is completed,and the circuit design of data processing instrument based on SJA1000 CAN controller and 20-bit multi-range A/D converter is done,and the circuit design of output control instrument based on SJA1000 CAN controller and TLC5616 D/A converter is completed.The software has realized that PC computer manage and watch and control and configures and proof the instrument based on CAN fieldbus using the CAN communication module,and realized data processing and CAN communication through CAN data processing instrument,and realized output control and CAN communication through CAN output instrument.By running of instrument,it is proved that stability and real-time and precision of instrument based on CAN fieldbus are better than traditional instrument. The error-delaying and data-switching and system-managing and anti-jamming of control system based on CAN fieldbus instruments are better than the system based on traditional instruments.