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SA-OPC-UA: Introducing Semantics to OPC-UA Application Methods

Badarinath Katti; Christiane Plociennik; Michael Schweitzer; Martin Ruskowski


Despite recent advances in Cloud manufacturingsuch as the introduction of Edge components, this applicationarea still suffers from inflexible production planning andstatic routing. In very dynamic scenarios such as high-speedmanufacturing, more autonomy of the Edge is desired inorder to enable it to react to unforeseen events. The conceptsof the Semantic Web, on the other hand, allow to connectmachines without human intervention. Semantic Web Services(SWS) have the potential to replace manual configurationof the control applications that connect and supervise thevarious manufacturing resources on the shop-floor. Severalspecifications exist to realize SWS; the concepts of one suchspecification, SAWSDL, can be rapidly incorporated into theOPC-UA specification due to the nature of the informationmodel of OPC-UA nodes. Our approach, called SemanticallyAnnotated OPC-UA (SA-OPC-UA), introduces the concepts ofSAWSDL to the OPC-UA protocol and in particular, to theapplication specific methods of OPC-UA. Consequently, SA-OPC-UA enables the creation of flexible orchestration plans ina manufacturing scenario controlled by cloud ManufacturingExecution Systems (MES).