OPC-based architecture of embedded web server

Abstract

This paper combines OPC (OLE for Process Control) standard to EWS (Embedded Web Server) in order to distribute an integrated service for accessing real-time and history data from control networks. A layer of OPC XML-DA (Data Access) service is added between web services interfaces and embedded operation system in OPC-EWS. Architecture of DCS (Distributed Control System) with OPC-EWS is described too. This OPC-EWS applies such technologies as OPC, Java and XML and links to Internet through TCP/IP. Therefore, accesses to all kinds of embedded devices and data share in the heterogeneous Internet/Intranet environment are implemented. At last real-time performance and security of OPC-EWS are analyzed. The experiments and application have demonstrated that the architecture has good performance and is feasible for real-time operation in DCS. © Springer-Verlag Berlin Heidelberg 2005.