A Comparison of OPC UA & Semantic Web Languages for the purpose of Industrial Automation Applications

The emergence of the Internet of Things (IoT) and Cyber-Physical Systems (CPSs) has revolutionized the industrial sectors around the world. Industry 4.0, a digitalization endeavour by the government of Germany for the factories of the future, aims to create intelligent, self-organized, and self-optimized smart factories by combining the IoT, cloud computing and artificial intelligence together. Interoperability is one of the crucial aspects of Industry 4.0 which requires standardized information models and exchange mechanisms for heterogeneous platform integration. Despite the development of various industry standards, this still remains the biggest burden due to multiple protocols, technologies, and policies involved. A common understanding of data semantics can be helpful in mitigating such problem. This paper provides a detailed comparison between the modelling approaches of Open Platform Communication Unified Architecture (OPC UA) and Resource Description Framework (RDF) and its extension languages. The aim is to garner a common understanding between these two modelling frameworks in order to generate a standardized mapping between them for the purpose of interoperable industrial applications.