A group of leading automation suppliers have joined forces to back what they believe will become the unifying communication system for linking industrial controls to each other and to the cloud. Tony Sacks reports on their hopes for the technology known as Time Sensitive Networking.
Industrial automation systems have traditionally relied on incompatible and non-interoperable standards to communicate between devices and to perform closed-loop control. As a result, users have often found themselves locked into proprietary systems and have not been able to optimise their automation installations. At the same time, some equipment vendors have had to develop several versions of essentially identical products to support the different communications ecosystems, limiting their scope for innovation.
The use of proprietary or air-gapped (disconnected) networks has also made devices and data hard to access and created technical barriers that hamper the need of the IIoT (Industrial Internet of Things) to be able to consume data anywhere in an infrastructure.
In an effort to solve these problems, a group of leading automation manufacturers have joined forces to back a technology known as OPC UA over Time Sensitive Networking (OPC UA TSN). This technology, based on open standards, which will allow devices from different vendors to interoperate fully with each other.
The group – which includes ABB, Bosch Rexroth, B&R Automation, Cisco, General Electric, Kuka, National Instruments (NI), Parker Hannifin, Schneider Electric, SEW-Eurodrive and TTTech – announced their backing for the standard at the SPS IPC Drives automation exhibition that took place in Nuremberg, Germany, last November. They said that they intend to support OPC UA TSN in their future products.
The group regards OPC UA TSN as a unifying standard for industrial automation and for IIoT connections. It combines an enhanced OPC UA Publisher/Subscriber (Pub/Sub) technology with the TSN Ethernet standards drawn up by the IEEE. The backers say that it provides all of the open, standard building blocks that will be needed to unify automation communications, and predict that OPC UA TSN will lead to the convergence of information technology (IT) and operational technology (OT) that is needed to achieve the IIoT and Industry 4.0.
TSN’s value is derived from unlocking the critical data needed to achieve the IIoT’s promise of improved operations driven by big data analytics and enabling new business models based on smart connected systems and machines.
TSN’s proponents believe that it will open up critical control applications such as robot and drive controls and vision systems to the Industrial Internet. This will make it easier to access data from these systems and to implement preventative maintenance and optimisation routines.
Several of TSN’s backers – including Bosch Rexroth, B&R, Cisco, Intel, Kuka, NI, Schneider Electric, Sick and TTTech – have already begun an open technical collaboration under the umbrella of the Industrial Internet Consortium (IIC) and the OPC Foundation. They hope that this “testbed” will help to create an open, unified, standards-based and interoperable IIoT system that will be suitable for deterministic and real-time peer-to-peer communications between industrial controllers and to the cloud.
The IIC testbed (see box) incorporates prototypes of future products that will support OPC UA TSN. The aim is to show compatible controller-to-controller communications between devices from different vendors using OPC UA TSN running over a standard IT infrastructure.
The testbed will:
• combine various critical traffic flows on a single network based on the IEEE 802.1 Time Sensitive Networking specification;
• demonstrate the real-time capability and vendor interoperability using standard, converged Ethernet;
• evaluate the security value of TSN and provide feedback on the secure-ability of initial TSN functions;
• show the IIoT’s ability to incorporate high-performance and latency-sensitive applications; and
• provide integration points for smart edge-cloud control systems into IIoT infrastructure and application.
There were some notable absentees from the group that announced their backing for OPC UA over Time Sensitive Networking at the SPS IPC Drives show. These include Siemens, Beckhoff, Rockwell Automation and the major Japanese automation suppliers. The backers say that other companies that share their vision of unified communications between industrial controllers and to cloud are welcome to join and to contribute to their collaborative effort.
Putting TSN to the test
The aim of the IIC’s TSN testbed is to demonstrate the value of the IEEE’s 802.1 Time Sensitive Networking standard in manufacturing applications. TSN powers a standard, open network infrastructure that supports multivendor interoperability and integration with guaranteed performance and delivery.
The technology can support real-time control and synchronisation ¬– for example, between motion applications and robots – over a single Ethernet network. At the same time, it can support other common traffic found in manufacturing applications, driving the convergence between IT and operational technologies.
The IIC testbed combines different critical control traffic (such as OPC UA) and best-effort traffic flows on a single, resilient network based on the IEEE’s 802.1 TSN standards. It is also designed to demonstrate TSN’s real-time capabilities and vendor interoperability using standard, converged Ethernet.
This testbed is an early implementation of TSN. It will show the value of the technology, as well as some of the challenges that vendors are facing in implementing the technology. Not only will it document the value of the TSN technology, but also provide feedback to the relevant standards organisations on areas of further clarification or improvement.
“Testbeds are a major focus and activity of the IIC and its members,” explains IIC executive director, Dr Richard Soley. “Our testbeds are where the innovation and opportunities of the industrial Internet – new technologies, new applications, new products, new services and new processes – can be initiated, thought through and rigorously tested to ascertain their usefulness and viability before coming to market.”
The testbed is being hosted by National Instruments. “TSNs are a critical attribute of a standard Internet model that enables the convergence of real-time control applications and devices onto open, interconnected networks,” says Eric Starkloff, NI’s executive vice-president of global sales and marketing. “This technology is necessary for the future of the IIoT and the IIC is providing a community, as well as enabling real-world testbeds, where industry leaders can collaborate to make this a reality.”
“Standardised and open communication is a key feature in our drive and control automation solutions,” adds said Ralf Koeppe, Bosch Rexroth vice-president in charge of engineering and manufacturing of electric drives and controls. “We regard the IIC TSN testbed to be a very important contribution for further improvement of vendor interoperability and of exchanging data in an IIoT infrastructure.”
The insights and concepts proven in the TSN testbed may be replicated in other testbeds in the future.
To learn more about the IIC testbed, visit http://www.iiconsortium.org/time-sensitive-networks.htm