An OPC UA client development for monitoring and control applications

Classic OPC, released by OPC Foundation, is well accepted and applied in industrial automation, which led to many OPC products on the market from a variety of companies. However, OPC technology was based on retiring Microsoft COM/DCOM. The OPC Unified Architecture was introduced as the new generation specification with the main goal of keeping all the functionality of Classic OPC and switching from COM/DCOM technology to state -of-the-art web services. The OPC Foundation has been also developing OPC UA Toolkit that provide a collection of libraries, classes, and interfaces which make developers and programmers easy to create and implement OPC UA components. However, this toolkit is insufficient for developers and programmers to implement real monitoring and control applications from industry due to the limitations of such a toolkit, the complexity of related decision tasks and information systems, etc. In this paper, an OPC UA (Unified Architecture) client framework is proposed and developed by using OPC UA specifications, Service Oriented Architecture (SOA), web services, XML, OPC UA SDK, etc. This framework minimizes the efforts of developers and programmers in learning new techniques and allows system arc hitects and designers to perform dependency analysis on the development of monitoring and control applications. The initial results from the system implemented by Visual Studio 2008 are also provided.