OPC Foundation Extends OPC UA with Standardized REST-Interface

Summary

April 17, 2023 - The OPC Foundation, a global organization dedicated to the interoperability in industrial automation and the Internet of Things (IoT), has announced that it expands the OPC UA standard with a RESTful interface to allow access from anywhere in the world to information made available by implementations of over 90 standardized information models by IT-applications.
 
This extension was requested by IT companies to ensure efficient and standardized access to important information: IT-applications need the ability to utilize the data from OT to use it in concepts like Data Spaces, Digital Twins and the Metaverse. These solutions often share information between multiple companies. In many cases, they exchange the necessary information via proprietary HTTP REST-Interfaces.
 
OPC UA is already equipped with many building blocks, such as session-less services and security features. Those building blocks already cover many aspects required to provide standardized information via RESTful interfaces. With the addition of HTTP REST, applications outside of the OPC UA ecosystem can now access this information. The OPC UA specification includes the transfer of meta-information such as server timestamp, source timestamp, value and quality of the individual information. Direct access via OPC UA allows these pieces of information to be shared up to the cloud and used in applications like the digital twin.
 
The expansion of OPC UA with REST is less likely to be adopted at the field level, but in gateways and cloud services. Cloud companies can now access standardized information and use it efficiently to optimize the business processes of their customers and unlock new use cases.
 
"This extension of OPC UA with a standardized mapping to a RESTful interface is a significant step forward in ensuring the interoperability of industrial automation and IoT systems," said Stefan Hoppe, president and executive director of the OPC Foundation. "By enabling access to information provided by implementations of over 90 OPC UA domain specific information models through standardized RESTful APIs, we are making it easier for developers to create OPC UA-enabled applications that can communicate with other web-based systems and applications such as Digital Twins and the Metaverse."
 
“When volunteering to chair this working group to cover the requirements of our projects, I didn’t expect such a big industry interest from others. With more than 50 companies participating, I’m sure the resulting extensions will be of great value for the entire industry,” said Erich Barnstedt, chief architect standards, Consortia and Industrial IoT, Azure Edge and Platform, Microsoft Corporation.

The REST group, as a sub-group of the OPC Foundation UA Working Group, will discuss use cases for OPC UA in Edge and Cloud computing environments using the proposed HTTP REST interface.
Non-exclusive examples for work items are:

• Generic REST interface definition for common OPC UA services (Read, Write, Call, …)
• Standardized mapping of OPC UA service parameters to datatypes commonly used in RESTful APIs
• How the existing session-less OPC UA service can be used with a REST interface.
• Define a concept to provide REST interfaces for Companion Specification use cases.
• Define requirements for security.
• Building prototypes and a demonstration.
• Define an OpenAPI-compatible REST interface using Swagger.

 About the OPC Foundation

The OPC Foundation has been promoting the development and adoption of the OPC information exchange standard since 1996. As an advocate and steward of these specifications, the OPC Foundation's mission is to help vendors, end users and software developers achieve interoperability of their manufacturing and automation resources. The OPC Foundation's mission is to provide the best specifications, technologies, processes and certification to ensure interoperability between different vendors and different platforms securely and reliably from embedded systems to the enterprise cloud. The Foundation supports over 920 members from around the world in industrial automation, IT, IoT, IIoT, M2M, Industry 4.0, building automation, machine tools, pharmaceuticals, petrochemical and smart energy in achieving this goal.