The Research And Realization Of OPC Data Access Rapid Client Development Library

The mission that this article want to solve is how to develop the OPC Rapid Client Development Library . First the article introduces the producing background, main characteristics and development condition of OPC technique, then analyzes its core COM/DCOM technique. In order to decrease the difficulty of OPC Client's development, and also to obtain more functions, it's necessary to realize a current OPC Rapid Development Library.This paper explains how to Create a Frame to develop the Library,and introduces how to develop a OPC client application with the Rapid Client Development Library (DLL), and describes how to use the functions that the DLL exports to connect a OPC server, to browse data in OPC server, to create a group object and a item object in detail. It's mentioned that using the callback functions to read, write and subscribe the data in OPC server. Finally it's necessary to test the Rapid Client Development Library by writing a client application, and the result of the test indicates that the Development Library has good flexibility and security for OPC Client.