Research Of Building Automation System Based On Lonworks Technology

With the development of economy, it is highly required for the Intelligent Building to function well and more and more Intelligent Buildings have been applied in our lives. Thus the objects which need to be supervised and controled are being diversification and complicacy. It is much necessary to build a kind of system which is provided with the uniform criterion, high reliability, agile establishment, good expansibility, convenient maintenance, good founction and low price. As an important part of the intelligent building, the development of the BAS has much important meaning.In this paper, LonWorks technique, which is a kind of new-style fieldbus, is recommended. Furthermore, based on this technique, a set of BAS is built. It introduces the constitution, the function, the hardware circuits, the design of all kinds of nodes, the software and the circuits agaist interferrences of the BAS. It includes temperature measure system, illumination control subsystem, fire alarm subsystem, garage safety alarm subsystem, TV supervise and control system and variational distribution or electicity subsystem. Through the operation interface which is supplied by the computer of the central control system, the whole building's running may be managed uniformly.LNS technique that is developed recently by Echelon Company is adopted by the central control system, which makes the personal computer used for supervise networks complete the function of networks installation, maintenance, superbvise and control. The program of the person-machine operation interface is wholly compiled through VB language. PC is connected with LonWorks networks by a LonTalk protocol adapter. MC143150 Neuron chip is adopted as the CPU of every function node and the programs of them are compiled by Neuron C language. Because only a few nodes were used in the BAS and the nodes were distributed nearly (The building is 6 layer and no more than 500m), one subnet is surficient.The system adopts twisted-pair as its transfer media, and the nodes communicats each other without router.