Applying Fieldbus Technology In Distributed Control System

Fieldbus specially designed to connect field devices and a control system is an open digital bidirectional communication network with multiple branches. As a fruit of the application of electronic technology, instruments and meters, control technology, computer technology and network technology, fieldbus technology meets the demand of industry automation which is growing more and more distributed and intelligent. With the huge benefit for terminal users, fieldbus technology has been resulting in a great change of automation instruments, Distributed Control System and Programmable Logic Controller in structure and function.However, regardless of domestic or overseas, DCS is still accepted as mainstream devices of process control, the socalled Fieldbus Control System can't take place of DCS right away. Then a question how to take full advantage of both fieldbus technology and DCS is being put into the schedule. There is a quite many means to integrate fieldbus technology into DCS, while this design emphasizes particularly on providing communication ability between Operator Station and field instruments, the same time reserving the advanced control and monitor function of the original DCS.In this paper, the author gives a detailed introduction of an interface circuit board and a support software both based on HART Communication Protocol and Serial Interface Communication Protocol. The hardware and software together play a key role in the communication between Operator Station and field instruments. In other words, they act as a HART Master which is responsible for adjusting parameters of the Slave, changing the Slave's running mode, diagnosing the Slave's faults and asking response with special information.The finished interface circuit board and support software with the unfinished Instruments Management Software running in Operator Station make up of the socalled Remote Management System of Field Instruments which will enhance the ability of DCS, improve the synthesized automation level of the whole system and competition capacity of enterprises.