Implicit Templates for Conformance Units in OPC UA Companion Specifications

Abstract

Due to its importance in the Industry 4.0 movement, the usage of OPC UA has increased in recent years. More and more vendor-independent and domain-specific models are developed as so-called Companion Specifications. OPC UA Profiles allow to subdivide functionality within the Companion Specifications, and thus offer flexibility to the standards. An OPC UA Profile is a set of individually testable entities called Conformance Units, which are also defined within the Companion Specification. In this work, similarities between Conformance Units defined by different working groups are analyzed and grouped in CU classes by the scope of the Conformance Units. For the most prevalent CU classes, textual templates are suggested, based on the typical formulations in existing Companion Specifications. These templates are intended to ease the development of Companion Specifications and the Conformance Units therein. The CU classes identified in this work suggest the templates can be used for more than two-thirds of the Conformance Units in a Companion Specification. The CU classes and templates are also a step towards automation in the generation of OPC UA Companion Specification Documents and test cases for the Conformance Units.