OPC unified architecture - Part 14: PubSub

IEC 62541-14:2026 defines the PubSub communication model. It defines an OPC UA publish subscribe pattern which complements the client server pattern defined by the Services in IEC 62541-4. See IEC 62541-1 for an overview of the two models and their distinct uses.

PubSub allows the distribution of data and events from an OPC UA information source to interested observers inside a device network as well as in IT and analytics cloud systems.

This document consists of

？ a general introduction of the PubSub concepts,

？ a definition of the PubSub configuration parameters,

？ mapping of PubSub concepts and configuration parameters to messages and transport protocols,

？ and a PubSub configuration model.

This second edition cancels and replaces the first edition published in 2020. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

a) Addition of a “Quantity Model” which can be referenced from EngineeringUnit Properties. The model defines quantities and assigned units. In addition it provides alternative units and the conversion to them.

b) Addion of rules for ValuePrecision Property: