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OPC UA (Open Platform Communications Unified Architecture)

Connections to other Concepts

Short Description

  • OPC UA Logical Layers.svg

  • OPC UA is a platform-independent standard through which various kinds of systems and devices can communicate by sending messages between Clients and Servers or Publishers and Subscribers over various types of networks

  • OPC UA can be divided into an architecture consisting of several layers
  • as base functionalities related to communication, the OPC UA Standard describes protocol bindings and encodings (e.g. HTTPS and XML) as well as communication schemes for Client-Server and Pub-Sub communication
  • another base functionality are the rules and conventions for information access. These include e.g. what data representations shall look like
  • All OPC UA communication includes security options. This is true for the communication between different systems (encryption and authentication of services) and for the information access, that can be restricted if needed
  • The information models contain specific data representations - they specify what to communicate using the OPC UA base functionalities
  • Generic information models like the base information model and the Devices model contain general data representations that are applicable in a broad context and thus vague compared to the more specific data representations
  • Domain specific Companion Specifications contain such more specific data representations: using and refining the generic types, they clarify what to communicate within a domain
  • The OPC UA model allows for using and refining all information content, e.g. adding information that is relevant in special scenarios. Manufacturer specific extensions may thus add information, that is missing in the standards for their respective use case

Facts and Figures

  • 2006 Release of V1.00
  • Current version: 1.05.02 (April 2022)

Stakeholders

Responsible for OPC UA - OPC Foundation

Collaborations for Companion Specifications (incomplete list) - ISA (International Society of Automation) - NAMUR - PI (PROFIBUS & PROFINET International) - umati (universal machine technology interface) - VDMA (Verband Deutscher Maschinen- und Anlagenbau e.V.) - VDW (Verband Deutscher Werkzeugmaschinenfabriken e.V.) - ZVEI e.V. (Zentralverband Elektrotechnik- und Elektroindustrie) - MTConnect - AML (AutomationML) - BACnet

Standardization - OPC UA is published as IEC 62541 IEC (International Electrotechnical Commission)

Use Cases

Industry Sectors

  • Cross-sector communication standard

International Distribution

Sources