Ensure OPC-UA interfaces for digital plug-and-produce

Experiences in industry has illustrated that ""Open Platform Communications Unified Architecture"" (OPC-UA) as upcoming de-facto standard for Industry 4.0 requires interoperability tests to support a digital plug-and-produce. Existing tools to validate OPC-UA implementations need to be applicable for such validations. Within the German national ""Internet of Things Test"" (IoT-T) project, we developed concepts and software for the validation of interoperability between different cyber physical systems using OPC-UA. The paper focuses on this part of the work and provides insights in the results. The results consists of industrial use cases, requirements, concepts and open source software. It also includes the comparison of the developments in the IoT-T project with the Compliance Test Tools (CTT) provided by the OPC Foundation (OPCF), which checks the conformity of the OPC-UA servers and clients against the OPC-UA specification.