Research On The Application Of OPC To Intelligent Building System

A typical building integration management system needs the interlinkage between the subsystem and the field device. It implements the consolidate management of the whole building through the share of the resource and the integration of the information. But each subsystem may be provided by different manufacturers in the practical integration, and then the different structures may exist in the application procedure, communication protocol and the database. So the drivers of the equipments needed to be designed become more and more in the computer monitor system software. It badly reduces the opening and the interoperability of each subsystem, and then blocks the establishment and the implement of the whole building system integration precept.At the same time, the OPC provides a uniform interface standard based on COM/DCOM technique. And the interoperability between the software and the hardware can easily be realized among different vendors while just needs to follow the OPC standard. The OPC adopts the modes of CLIENT/SERVER: the manufacturer provides the driver of the equipment and the standard OPC server code; the software vendor accesses the server by the OPC standard and then the communication with the equipment can be easily realized.This paper first introduces the OPC technique, ATL and IDL language, and then lucubrates the OPC DA 2.05a specification. At last the detailed development flow of OPC server based on Visual C++6.0 and the client application based on Visual Basic is studied, at the same time the demo code has been written.The study indicates that the OPC based on CLIENT/SERVER mode separates the responsibility between the software and hardware manufacturers. The hardware manufacturer is more familiar with their equipments, so the driver written by them is more dependable. While the software manufacturer can take no care of the device driver, so they can just pay attention to the perfection of the subsystem function. As a result, the interoperability between each subsystem and device is further improved and then opening of each subsystem is also improved. So the system integration becomes very convenient.