OPC UA Field eXchange (UAFX) Specifications Released by OPC Foundation

The OPC Foundation (OPCF) announced that its Field Level Communications (FLC) Initiative has released the first set of OPC UA Field eXchange (UAFX) specifications, which lay the groundwork for using OPC UA at the field level. Four years in the making, these UAFX specifications have passed in-depth OPCF member reviews and extensive prototyping to ensure their implementations maintain cross-vendor interoperability. Automation vendors can now start adopting UAFX functionality in their offerings, and end-users can look forward to the advantages UAFX-based field communications offer.

The released UAFX specifications consist of four parts focused on exchanging process and configuration data between automation components. The parts use OPC UA Client/Server and PubSub extensions in combination with peer-to-peer connections and basic diagnostics.

• Part 80 (OPC 10000-80) provides an overview and introduces the basic concepts of using OPC UA for field level communications.
• Part 81 (OPC 10000-81) specifies the base information model and the communication concepts to meet factory and process automation’s various use cases and requirements.
• Part 82 (OPC 10000-82) describes networking services, such as topology discovery and time synchronization.
• Part 84 (OPC 10000-84) defines the Controller Profile with details to fulfill conformance requirements.

This release lays the foundation for upcoming specification extensions, which will address Controller-to-Device (C2D) and Device-to-Device (D2D) use cases and development of application profiles for motion control devices, field instruments, and I/O peripherals.

At the 2022 SPS show in Nuremberg, the OPC Foundation showcased a multivendor UAFX-based interoperability demonstration comprised of automation components from twenty manufacturers, including ABB, Beckhoff, Bosch Rexroth, B&R, Emerson, Festo, Honeywell, Hirschmann/Belden, Huawei, Keba, Kuka, Mitsubishi, Moxa, Omron, Phoenix Contact, Rockwell Automation, Schneider Electric, Siemens, Unified Automation, Wago and Yokogawa.

The demonstration showcased horizontal communication between 3rd party controllers, i.e., controller-to-controller (C2C) communications. Utilizing the UAFX extensions, the controllers share process data using UAFX Connections and PubSub mechanisms via UDP/IP over wired Ethernet, Ethernet TSN, and 5G wireless connections. The UAFX Connections utilize UAFX Publisher and UAFX Subscriber functionality, and the controllers are configured and interconnected via built-in or stand-alone UAFX Connection Manager software. Siemens and Unified Automation implemented the UAFX Connection Managers used in the demonstration. The controllers in the demonstration were monitored in real time via a central dashboard, which visualized the status, selected process data, and other information from the UAFX asset information model for each automation component.