Design Of Fieldbus System Instrument Based On ModBus Protocol

With developing and appearing of micro-electronics technology, Fieldbus technology has already attracted attention of instrument industry at home and abroad. ModBus 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 repid-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.The field control system base on fieldbus technology is developmental tideway,compared with the old control system,A maximal strongpoint is opened to other factories.This paper analyze and discuss capability and characteristic of fieldbus technology, and input instrument based on ModBus field bus is discussed in detail.By running of instrument, it is proved that stability and real time and precision of instrument based on ModBus fieldbus are better than traditional instrument. The error-delaing and data-switching and system-managing and anti-jamming of control system based on ModBus fieldbus instruments are better than the system based on traditional instruments.