OPC UA Publish/Subscribe Extension

The OPC UA Publish/Subscribe communication extension was first released by OPC Foundation in OPC UA Specification Part 14 in February 2018. For our existing OPC UA Client Server SDKs we made available the UA PubSub AddOn (UA PubSub-Stack and integration code into the respective SDK) as a new combined bundle package. The architecture is generally identical in all SDK, however the implementation depth of the features may differ in each SDK. Please check the UA Profiles listed for the PubSub-AddOn for details.

OPC UA PubSub Stack

The most important new component is the OPC UA Pub/Sub-Stack. The stack itself contains different functionalities, mainly the protocol adoption (which currently is UDP only) and second the UA Binary Encoder/Decoder (currently no JSON endocer), and additionally the UA Pub/Sub Stack has interface for configuration which support the configuratoin structures as defned by the OPC Foundation. For external high precision clock the stack has an external timer interface.

The UA PubSub-Stack provides two possibilities for data integration:

  • Default data integration, via SDK
  • Custom data integration, directly

DEFAULT data integration uses the PubSub-Module for integration of data. The PubSub Module acts as internal Client to the Server SDK. The existing Data Provider remains unchanged and the data used for PubSub is just configured. All configuration parameters required for PubSub communication are passed to the PubSub Module.

CUSTOM data integration is optional. The data can directly be provided to the PubSub-Stack for encoding/decoding. By this the SDK is bypassed. The configuration information is still provided by the PubSub module, status information can be monitored. Such direct custom data integration is used for deterministic real time solution, such as TSN. 

C++ Based OPC UA Client & Server and PubSub SDK (Bundle)

The PubSub SDK & Toolkit includes precompiled libraries and header files, documentation, and samples for all compilers supported by the selected platform. This SDK supports multithreaded compilation only.

  • PubSub SDK & Toolkit for the UADP
  • supports online and offline configuration
  • includes Client SDK
  • includes Server SDK
  • designed for PC platforms and enhanced embedded Systems
  • portable C++ class library
  • implements all common UA functionality as reference implementation
  • provides sample implementations for Windows and Linux

The C++ based OPC UA Client & Server and PubSub SDK is available as source code license only. Upgrade packages for Client/Server license holders available.

ANSI C Based OPC UA Client & Server and PubSub SDK (Bundle)

The PubSub SDK & Toolkit includes precompiled libraries and header files, documentation, and samples for all compilers supported by the selected platform. This SDK supports single thread compilation only.

  • PubSub SDK & Toolkit for the UADP
  • supports offline configuration only
  • includes Client SDK
  • includes Server SDK
  • designed for PLC platforms and embedded Controllers
  • provides sample implementations for Windows and Linux

The ANSI C based OPC UA Client & Server and PubSub SDK is available as source code license only.