The Application And Study Of OPC For Industrial Control System

With the development of computer technology, more and more softwares and hardwares are used in industry control field and system integration becomes harder than before. So it is very necessary to use the same standard to communication for both user and vendor.Combined with standards like OLE for Process Control (OPC), TCP/IP, Internet, and Windows software, industrial networks based on the Ethernet standard is attractive to use for openness and interoperability among factory automation, process control, and business applications.There are some problems in existing solutions like Ethernet-fieldbus system, enven total Ethernet control system. Also, with different Ethernet communications protocols being defined by various fieldbus organizations,it is more difficult to achieve interoperability among the different industrial networks.OPC Data Access (DA) primarily provides vertical data integration and interoperability between measurement and automation systems on the manufacturing floor and client application. OPC client applications can communicate with one or more OPC servers from different suppliers. OPC Data eXchange(DX) makes it possible by defining a set of interfaces that provides interoperability and allows data exchange among devices and controllers connected to Ethernet networks using different fieldbus protocols. This paper provides a solution leveaging OPC DA and OPC DX standard for the total integration of industrial Ethernet control system, for enhancing the openness of the syetem, and this paper focus on the research of the realzation mechanisam of system's vertical and horizontal data transfer using OPC DA and OPC DX.First, OPC inner mechanism based on COM/DCOM and the interaction of Client/Server system components are analyzed. At the same time OPC DA Client/Server application scheme is designed and implemented. The development consists of two parts: the design and its realization of OPC Client;the developmentapproach and its practice of OPC Server. Several difficulties such as OPC interfaces' realization and multi-view displays are overcome during both OPC Client and Server's development. The interaction testes among the developed Client and Server, also some other Client and Server are finished, by which proves the applicant openness because of OPC DA technology.An OPC DX Server constructure model is builded in this paper after discussing some existing solutions of horizontal data integration. This paper researches some critical problems of this horizontal data exchange communication mechanism with OPC DX universal configuration tool in the end.