OPC Technology And Its Application In The SCADA System

OPC (OLE for Process Control), which is the application of Microsoft's OLE (Object Linking and Embedding) technology in process control system, provides a unified standard for Object-Oriental Design in industrial automation software. The aim of OPC is to provide a standard mechanism for communicating with numerous data sources, which are either from the field devices or from the databases.This paper described the newest software interconnecting standard in the industrial control field-OPC technology, introduced its background and development process. On the basis of detailed knowledge of OPC specification and COM/DCOM, combining with the real project?zhongliang mountain tunnel of chengyu highway, this paper analyzed the feasibility and practicality of OPC technology, instructing the research and development of tunnel monitor system.According to the OPC toolkit supplied by huafu company in Beijing, this paper developed an OPC data access server and alsodesigned an WinCC application with the WinCC software. After which, the two sections have been used in the SCADA system and industrial control network based on Internet respectively, every application can communicate through the standard OPC interface, greatly enhancing the extensibility and compatibility of the system. Meanwhile, it also increased the reliability and stability and the maintenance and update of the system.In this paper, the connecting process of WinCC application and OPC server are also discussed, the amalgamating method of control system and enterprise information system using OPC technology are also presented.OPC is the perfect combination of software technology and automation technology in foreign countries, it brings about a revolution for the integration of software and hardware of the industrial control field, it denotes the future trend of the communication standard of process control system.