| OPC (OLE for Process Control) is based on Microsoft's OLE (object linking and embedding)/COM (Component Object Model) technologies, which is an industry specification and standard generated to settle the communication problem between industry client computer and various equipment drivers. OPC technology specification is established by OPC foundation, which provides unitive data accessing software and hardware interface standard. OPC technology has been more and more areas of industrial control hardware and software manufacturers the recognition and support of industrial control software has become the accepted standard. Source text items semiconductor lighting project for the state 863 for the third generation of Xi'an University of Electronic Science and Technology production MOCVD(Metal Organic Chemical Vapor Deposition) system equipment, according to the technical requirements, carried out monitoring of MOCVD control system interface optimization and design.In this paper, Visual C + + 6.0 as a development platform, using OPC Data Access 2.05 specification development of the OPC client application to achieve the main interface and basic functions, and a deep understanding of OPC protocol specification based on the re-packaging of some common API (Application Programming Interface, Application Programming Interface) functions, the preparation of its own header file, used in the client program. The client program through the OPC custom interface to access OPC server, the method successfully realized the right hardware to read the data without having their own independent development and hardware communication program. The OPC client program developed after the success of achieving access to OPC server program code can also be applied to any other OPC server with a monitoring system, improve the program code reusability.Use of the OPC custom interface client programs applied to the MOCVD monitoring system, in the completion of OPC servers and hardware connection configuration, the use and development of client-side program, using OPC technologies asynchronous and subscription-based communication mechanism to successfully read the OPC server data, thus achieving control of the MOCVD system, the flow, pressure, control the volume and alarm signal monitoring, MOCVD monitoring system greatly improved the efficiency of data reading and writing to overcome the phenomenon of the screen update delays to optimize the monitoring system interface. At the same time, this paper work carried out after the OPC technology research and product development OPC also has a certain significance. |
