Posted to News on 20th Apr 2018, 10:22
The state of Time-Sensitive Networking in the IIoT
Recent market reports recognise the Industrial Internet of Things as a burgeoning opportunity and game changer for the industrial automation equipment market. A 2017 report from IHS forecasts the industrial sector as being one-third of the total connected IoT devices by 2020 (Source: IoT Trend Watch).
Industrial and transportation companies will demand the same high levels of reliability, security and safety for their control systems within the IoT as is provided today by a multitude of specialised but often proprietary and segregated communication technologies; but these requirements with regards to reliability and security must be addressed in a much more connected and open infrastructure, leading to challenges in deployment and diagnosis not seen before in this type of system. With more operations seeking streamlined processes that save money and time, network infrastructure improvements are a key step in the development of systems. This means that there will be an increasing need for interoperability, efficiency and determinism on the network as new automation capabilities arise. Enter: Deterministic Ethernet-based networking.
In 2016, Avnu Alliance member National Instruments shared a piece in MachineBuilding.net on the IIoT and the need for Time Sensitive Networking (TSN) in these increasingly connected networks. Since then, Avnu Alliance and members have worked on several major initiatives to drive TSN to the forefront of IIoT systems and network infrastructure.
The Industrial Internet Consortium TSN Testbed
As the world's first testbed for TSN, the IIC's TSN for Flexible Manufacturing testbed was developed with two major goals: to show TSN's readiness to accelerate the marketplace and to highlight the business value of adopting open, interoperable standards in automation networks. It stands as a showcase of the value that TSN standards and the ecosystem of manufacturing applications bring to the market, including the ability for IIoT to incorporate high-performance and latency-sensitive applications. IIC member participants include key industry leaders - such as Analog Devices, Belden/Hirschmann, Bosch Rexroth, B&R, Cisco, Hilscher, Intel, Kuka, National Instruments, OPC Foundation, Renesas Electronics, Schneider Electric, Sick, TTTech and Xilinx - many of which are also Avnu Alliance members. The work coming out of the TSN Testbed already has a direct impact on many suppliers and manufacturers who see the technology as a value add for their system structure.
The benefit of the testbed is that it demonstrates real-world industrial-use cases leveraging TSN. One such envisioned use case is a setup of two separate large-scale robot and automation control suppliers who are seeking to implement TSN technology to increase interoperable communication between their devices and systems. They will co-ordinate and manage controllers and the monitoring of the sensor data between robots and the controllers. This co-ordination requires a combination of receiving highly time-sensitive, synchronised information from sensors and then passing control commands back into the environment to other types of devices on the network. Without TSN, these companies would have to perform this communication with separate proprietary, non-standardised networking technologies that may not talk to each other on an IoT network.
Interoperability testing via the IIC TSN Testbed is rapidly progressing, with eight hands-on plugfests taking place in the USA and Europe over the past 18 months. As a key collaborator of the IIC's TSN Testbed and sponsor of NI's IIoT Lab, Avnu Alliance has a special interest in ensuring the continued enhancements to Ethernet that TSN brings. Avnu is the third-party independent organisation providing conformance testing for interoperability of TSN and related standards, giving industrial vendors the ability to respond to market demand.
Conformance testing and Avnu Alliance's role in events driving the future of TSN
Expanding industry education is a key goal of the Avnu Alliance and its members. Cultivating conversations that lead to the greater participation and implementation of TSN begins at the member and organisation level, with members taking an industry leadership approach to education around the benefits of TSN for IIoT networking. In October 2017, Avnu Alliance and Industrial Internet Consortium (IIC) held an Interoperability Workshop with more than 20 industrial companies across silicon, infrastructure and automation to demonstrate interoperability of TSN devices. This week-long face-to-face workshop focused on vetting the usage of TSN for flexible manufacturing and working on configuration for these systems. The lessons learned from the ongoing IIC TSN Testbed activities and the results from this workshop contributed to the conformance test development and will continue to feed into standards revisions as necessary.
Testbeds and plugfests help test for a certain degree of interoperability and allow us to create real-world systems as an early check for problems but conformance testing ensures alignment with the standards in a more complete way. Leveraging the work done through these relationships and interoperability workshops helps to create a stronger environment for interoperability. In November 2017, Avnu Alliance released the first set of TSN conformance test plans for time synchronisation of industrial devices, available for test houses to implement.
As the standards and networks continue to evolve, so does Avnu's work to define and certify the standard foundation. This eventually will include mechanisms such as frame pre-emption, redundancy, ingress policing and security. In addition, Avnu's defined foundation will continue to support additional capabilities, including support for multiple IEEE 1588 profiles, guidelines for scaling to very large network architectures, and aggregation/composition of multiple networks into a single TSN-enabled network domain.
The conformance testing and certification provided through Avnu will be critical to provide the needed foundation for interoperable IIoT networks and give industrial vendors a more streamlined vehicle for participation in the TSN ecosystem.
Avnu is committed to speeding up the path to an interoperable foundation. To this end, Avnu members have made open source code available for 802.1AS timing and synchronisation in the OpenAvnu repository on GitHub. To encourage and enable multiple industry groups, vendors and protocols to share a TSN network, Avnu has outlined the system architecture and requirements for this industrial model built on an Avnu certified foundation in a document entitled 'Theory of Operation for TSN-enabled Industrial Systems', which is available for download. This document introduces the fundamental mechanisms needed for a system architecture to build on, including time synchronisation, quality of service using scheduled transmission and network configuration and walks through the requirements of several industrial use cases including how to enable and integrate non-TSN technologies where needed.
Avnu Alliance members have created this document to help designers and engineers in the industry understand the real-world application context and build a TSN network that is configured for multiple vendor and industry groups. Avnu's defined foundation will continue to support additional capabilities, including support for multiple IEEE 1588 profiles, guidelines for scaling to very large network architectures, centralised and distributed configuration for the network, and aggregation/composition of multiple networks into a single TSN-enabled network domain.
Look for news to come and learn more about Avnu Alliance at www.avnu.org. Follow this link if you wish to download the Theory of Operations paper.
