The Development Of Building Automation System Programmable Logic Controller Based On Ethernet

Programmable Logic Controller is based on microprocessor, integrates computer technology, automation technology, and communication technology. It is a kind of universal industrial automatic control equipment. It has already become one of three biggest supports of modern industrial control. PLC'market is very large in China, but the factory in our country which has its own Intellectual Property is very few, and unable to meet domestic market's demands. To the question that the programmable controller exists while studying, combine the project of " programmable controller of control system of intellectual building based on Ethernet " of one company in Beijing, develop a set of programmable controllers of Ethernet in order to realize the integrating effectively of each control point of intellectual building. The dissertation adopts RCM3000 core module and designs hardware of PLC from structure and operation principle of the programmable controller at first. On this basis, utilize C language to develop a set of explanation subprograms corresponding to every command; users can realize corresponding operation according to existing PLC programming way. Then the dissertation studies the real-time character, determinacy, bus supplying power and inter-operating character when Ethernet is applied to the fields of fieldbus. Finally, establish real-time database, WEB service module and integrate interpreter, real-time database and WEB service together through XML language. Through experiment, we can execute program and send message to real-time database and up computer successfully.