OPC UA Service Discovery and Binding in a Service-Oriented Architecture

The OPC UA (Open Platform Communications Unified Architecture) technology is found in many industrial applications as it addresses many of Industry 4.0's requirements. One of its appeals is its service-oriented architecture. Nonetheless, it requires engineering efforts during deployment and maintenance to bind or associate the correct services to a client or consumer system. We propose the integration of OPC UA with the Eclipse Arrowhead Framework (EAF) to enable automatic service discovery and binding at runtime, reducing delays, costs, and errors. The integration also enables the client system to get the service endpoints by querying the service attributes or metadata. Moreover, this forms a bridge to other industrial communication technologies such as Modbus TCP (Transmission Control Protocol) as the framework is not limited to a specific protocol. To demonstrate the idea, an indexed line with an industrial PLC (programmable logic controller) with an OPC UA server is used to show that the desired services endpoints are revealed at runtime when querying their descriptive attributes or metadata through the EAF's Orchestrator system.