Design And Development Of OPC Data Acquisition System Based On Wince Terminal

The development of computer and network technology has greatly improved the performance of different control systems in industrial fields. The OPC technology enables the different products to intercommunicate and integrate, which promotes the standardization of industrial fields. However, There still exists some problems in the application of the OPC Technology:(1) The OPC DA specification that most widely applied is based on the COM/DCOM technology, thus it can not get through the firewall, and its application is limited in local area network;(2) Most research of the OPC technology’s application is on the PC. Using PC as the platform of data acquisition will bring high cost to the entire monitoring network;To solve the above problems, this paper lucubrated two specification of the OPC technology, and combined the advantages of embedded system. The main contributions are as follows:(1) Analyzed the COM/DCOM and Web Service technology(the technical basis of the OPC DA and the OPC XML-DA specifications). summed up the advantages and disadvantages;(2) Considering the actual demand of the data acquisition, a data acquisition system that run on Wince terminal was designed by in combine with the advantages of two specifications,(3) The Windows CE system platform that meet the requirements was customized. The frame structure of the data acquisition system was detailed designed. The system is consisted of a data acquisition management software and a Web Service gateway software.(4) The data acquisition management software that based on the OPC DA specification was developed. The software deployed in different terminals within the local area network, it integrates the device for data acquisition by using dynamic link library technology, and gathers data to the Web Service gateway.(5) The Web Service gateway software that based on the OPC XML-DA specification was developed. The gateway manage the data acquisition software within the LAN, and cache the data gathered by using database. It also provide standard services to the client outsider of the LAN in the form of Web Service. the subscription function was highlight designed and developed.The system designed in this paper can ensure the real-time and high efficiency of data acquisition, support the cross network access, and reduce the cost of data acquisition. Further more, the system can be integrated with a third-party data acquisition software in order to construct a fully functional and high-performance data monitoring network, which has a certain industrial practical value.