Distributed Control System Based On Lonworks Technology

With the development of microelectronics technology and computer networkcommunication technology, the automation control meter has developed on the basis ofdistributed fieldbus technology rather than single control meter. The fieldbus is now thehotspot of application in automation field. In the application of fieldbus technology, somefeatures, such as reliability, expansibility and transfer speed of communication areimportant. And the LonWorks, based on LonWorks technology, with its completeprotocols, diversity of net topology structure and strong ability in network communication,excels in the fieldbus field. So developing software and hardware product with LonWorksfieldbus technology and applying them into control projects is one of the key researchdirections for automatic control meters.In this thesis, a liquid-level control system is developed with LonWorks technologyof Echelon Company and the design method of distributed control system is also discussed.In the system, the architecture is divided into two parts: the level of position machinemonitor and control and field control. Firstly, the windows-oriented LNS technology ofLonWorks is used in position machine, and dynamic data exchange technology andLonTalk protocol are used in the real-time communication between position machine andfield intelligent control nodes. Then Network Configuration Software—Intouch, GraphicProgramming Software—Onion and Network Management Tool—Visual Lon are applied inthe development of intelligent distributed control system software. Finally, four functionsare realized to monitor, control, manage and maintain the liquid-level.