Glossary · Industrial communication
OPC Unified Architecture (OPC UA)
Also known as: OPC UA, OPC Unified Architecture
German: OPC UA
In industrial communication, OPC Unified Architecture (OPC UA) is a platform-independent, service-oriented architecture of the OPC Foundation for secure data exchange, combining transport protocols, security, services and an extensible information model. It is published as the OPC 10000 series and as IEC 62541.
- Industrial communication
- Standards
In one sentence
OPC UA is the OPC Foundation's platform-independent architecture for secure industrial data exchange with an information model (IEC 62541).
Example
A machine's OPC UA server exposes its state, counters and alarms according to the OPC 40001 machinery companion specification, so the MES can read them without custom mapping.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
How it applies
- Engineering: OPC UA organizes data as nodes in an address space with types, references and methods. Companion specifications define industry-specific information models, for example for machinery, robotics or injection molding.
- Security: Application certificates, signed and encrypted communication and user authentication are built in, but must be configured. "Security mode None" is often left enabled after commissioning.
- Integration: Client-server communication suits request-response and subscriptions; OPC UA PubSub suits one-to-many distribution, over UDP or MQTT.
- Documentation: The documentation team documents the supported profiles, companion specifications, namespace, security policies and certificate handling. OPC UA information models are also a source for semantic documentation, similar to an Information model in iiRDS.
Protocol vs. data model
OPC UA is both: a set of protocols and services, and a framework for Data models. That is its main difference from MQTT or Modbus, which only transport data.