Since 2006, the OPC Unified Architecture (OPC UA) has provided a multivendor, multiplatform information modeling and communications architecture for industrial networks. The machine-to-machine (M2M) abstract layer is responsible for connecting thousands of disparate industrial automation devices and applications, regardless of the underlying fieldbus network.

Since that time, the ubiquitous Ethernet communications protocol has also made inroads into the industrial sector, thanks in large part to work in the IEEE 802.1 Time-Sensitive Networking (TSN) task group. Although originally developed for audio/video applications within vehicles, the hard real-time, non-negotiable latencies of Ethernet TSN is a perfect fit for Industrial IoT deployments down to fieldbus networks.

The OPC Foundation recently launched a new taskforce with the goal of integrating OPC UA and TSN to join the industrial enterprise with operational devices in the field.

“Simply said, OPC UA was used by the fieldbus organizations to have their data transferred to the cloud-based applications,” said Thomas Burke, Strategic Marketing Officer, OPC Foundation.

“I see significant value where OPC UA over TSN can be put into a field device augmenting the capability of the field device’s connection already in the standard fieldbus network,” Burke stated. “The ability to publish data from a field device and have this information integration [of] the deterministic view delivered in a high-speed fashion to other disparate applications and devices is invaluable.”

OPC UA + TSN-IA in Industrial IoT deployments

Combining OPC UA and TSN down to the field level is significant because it enables devices on separate fieldbus networks to exchange data. As Industrial IoT deployments grow in size and diversity, such transparency is a major advantage for organizations in the industrial automation sector.

“The [new OPC UA] working groups will closely align with the TSN Profile for Industrial Automation (TSN-IA-Profile), which will be standardized by the IEC/IEEE 60802 standardization group,” Burke explained. “This will help ensure that a single, converged TSN network approach is maintained so that OPC UA can share one common multi-vendor TSN network infrastructure together with other applications."

The OPC Foundation’s TSN-IA-Profile initiative will deliver an open, cohesive approach to implementing different TSN-based technologies within OPC UA. Its goal is to provide vendor independent end-to-end interoperability down to field-level devices through working groups that will identify, manage, and standardize various TSN-based application profiles within the OPC UA standard. 

Activities of the TSN-IA-Profile initiative include:

• Mapping OPC UA application profiles related to real-time operations on Ethernet networks, including TSN
• Harmonization and standardization of application profiles such as I/O, Motion Control, Safety, and System Redundancy
• Standardization of OPC UA information models for field-level devices, including device descriptions and diagnostics for online and offline devices leveraging TSN
• Definition of certification procedures

“We will definitely focus on standardizing information models for both offline and online field level devices leveraging the TSN capability,” said Burke. “The whole focus is to be able to provide device description and diagnostics as well as runtime data in a seamless fashion from the field level devices.”

OPC Foundation and TSN: Moving forward

The OPC Foundation’s information architecture is key in the OPC UA over TSN strategy, allowing rich data information models to be seamlessly published and consumed by subscribers. The Foundation is also currently outlining the certification process for OPC UA + TSN-compliance.

“Certification is one of the key benefits of the OPC foundation infrastructure. We plan to make sure and focus on defining all of the certification procedures necessary so that we can have OPC UA over TSN certified for interoperability and information integration,” Burke added. “We will partner with the necessary organizations to deliver the highest quality certification process.”

For more information, visit https://opcfoundation.org.