OPC Historical Data Access

Abstract: In 1996, a new standard was announced that should serve as a software interface to exchange process data and to solve the problem to exchange process data using different industrial protocols and communication systems. A successful story started since then with few additional standards like the Alarm and Event standard using the OPC approach and some revisions and new editions. Ten years later a new approach was created that unified all existing standards and was also concerned with e.g. interoperability, security and web-based systems. This paper details the different OPC standards, tries to answer the question why this standard is important for industries and academia and where current research and development utilising those standards.

Abstract: OPC Unified architectures (OPC UA) is a new software interface specification and application framework based on web service for plant automation systems which communicate with each other over the internet. The security issue holds the key to its development for technology feature based on web service. In this paper, the OPC UA security issues are discussed from the two views of network environment security and communication security in OPC UA applications. The network security deployment solution based on distributed firewall was proposed to ensure the host of OPC UA server and client against the different attacks. Sequentially the improved OPC UA security model based on the existing model was presented. A security strategy management module was added into the model, by configuring the module, the security characteristic of OPC UA applications system can adapt to the different security level. At last the information model of the security model is designed. By the above means, the OPC UA communication security and communication efficiency can be balanced better, and it provides the guideline for the development of OPC UA server and the OPC UA applications.