OPC Foundation releases OPC UA Field eXchange specifications

Nov. 18, 2022
Specifications lay the groundwork for using OPC UA at the field level

The OPC Foundation's (OPCF) Field Level Communications (FLC) Initiative 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. As such, 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 the Controller-to-Device (C2D) and Device-to-Device (D2D) use cases and the development of application profiles for motion control devices, field instruments and I/O peripherals.

Also read: OPC Foundation, FieldComm Group to collaborate on OPC UA Field eXchange

At the 2022 SPS show in Nuremberg, the OPC Foundation will be showcasing a multivendor UAFX-based interoperability demonstration comprised of automation components from 20 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 will showcase horizontal communication between third-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 that will be used in the demonstration. The controllers in this demonstration will be monitored in real time via a central dashboard, which visualizes the status, selected process data and other information from the UAFX asset information model for each automation component.

Peter Lutz, director Field Level Communications of the OPC Foundation, said: "We are happy about the progress that our working groups have made over the last months. The publication of the first UAFX specification release and an impressive multivendor live demo are major achievements because the specifications are now mature so that real products can be implemented and conformance tests can put into place."

Since the start of the Field Level Communications Initiative in November 2018, more than 320 experts from over 65 OPC Foundation member companies have contributed to generating the technical concepts and elaborating the specification contents for extending the OPC UA framework for field level communications, including Determinism, Motion, Instrumentation and Functional Safety. 

Thomas Brandl from Bosch Rexroth, who chairs the Field Level Communications Initiative Steering Committee, said: "It is remarkable how many companies - including all major automation suppliers and key technology providers from all over the world – have been contributing to our initiative and how constructively all the experts have been working together to advance the common goal of bringing OPC UA to the field level."

Stefan Hoppe, president OPC Foundation, added: "Big congratulations to all involved in these specifications. OPC UA already serves as a communication backbone in several process and factory automation initiatives due to its versatility, security and vendor independence. As a first step, the UAFX extensions close the gap of standardized horizontal controller-to-controller communication and will be referenced by many other organizations as a base technology foundation."