Study And Appilication Of Fieldbus In Valve Controller

Valve is a kind of normal device for many fields, valve electric actuating equipments are widely used to operate and regulate valves in modern control system. Valve is controlled with valve electric actuating equipment, and the valve electric controller is a main section of the valve electric actuating equipment. Industrial fieldbus technology is nowdays a hot point in the area of industrial automation. It integrates a lot of technology including digital communication technology, computer technology, automation technology, Internet technology and intelligent instrument technology, and makes up of a digital, intelligent communication and controlling system. This thesis brings up a new valve controller based on fieldbus, and this may make valve controller walk further on remote control.This thesis reseaches on realized slave interface on valve controller which is based on which is based on microchip and DSP technology, makes some useful research work on slave protocol of Modbus and Profibus-DP, and puts forward the design of slave interface with Modbus and Profibus-DP which will provide a great way in fieldbus applicating. The author finds out the situation about valve controller and fieldbus technology in and out, analyzes the application of fieldbus technology especially its advanced appicating in valve controller, briefly introduces the hardware construction and software design of the bi-chip controlling structure based on TMS320LF2407A and ATmega64, following describes in details the protocol contents of Modbus and Profibus-DP, duscusses their interface technology, designs and realizes interface module with Modbus and Profibus-DP on valve controller, consequently achieving remote control by data communication.This thesis also makes a detailed introduction of hardware design of Modbus which based on RS-485 criterion, plans program of fieldbus slave following data-transfer protocol of Modbus and Profibus-DP. In the end, the thesis point out the future work and the prospect in this field.Now the study achieves the original goal, and successfully applicating Modbus and Profibus-DP on intelligent valve controller. The research achievement of this thesis has been successfully applied into the valve controller, and the system is successfully put into use. The application of the research in this thesis has made a great promotion to realizing the intelligentized, digital and distributing valve control system and application of fieldbus in industrial equipments. And I think it is of some referable points for the future reseach in this field.