The Analysis and Research of OPC XML-DA Server

The technical defect of the OPC (OLE for Process Control) DA (Data Access) server which is based upon the technology of COM (Component Object Model) has appeared prominently while transmitting the message in the internet. So it's important to bring forward the technical advantage and necessity of OPC XML-DA server based on the web service technology. The transmission of the plant message across the internet have been facilitated, in the meanwhile, the data fusion between MIS (Management Information System) and FCS (Field Control System) have been promoted. This paper presents the scheme of the middleware server which is realized by mean of “gSoap” development kit. The interface of the DA server based on the COM could be connected with web service interface based on the XML (Extensive Makeup Language) / SOAP (Simple Object Access Protocol). The experiment justifies high efficiency and feasibility of OPC XML-DA server in the internet communications.