Ethernet with TSN insights
- Ethernet changes from 2018 enable deterministic performance, something Ethernet could not deliver when applied to an open network.
- Ethernet with TSN allows end users to reduce the number of networks required for their operations, as they can merge different data traffic streams together while ensuring determinism.
- By converging multiple types of data, TSN offers a key way to merge OT and IT.
- Management of devices is enhanced through Ethernet with TSN by enabling a greater level of communications.
What is Ethernet with Time Sensitive Networking (TSN)?
Ethernet has gone through significant enhancements over the years, and changes released in 2018 enable deterministic performance, something Ethernet could not deliver when applied to an open network. In a closed system, where all devices can offer coordinated communications, for example through token passing, it was possible, but in an open network, with unbounded communications, determinism is impossible. TSN is a technology that sits at Layer 2 – Data Link of the OSI model to expand the capabilities of current Ethernet networks. More precisely, this innovation is described by the IEEE 802.1 set of Ethernet sub-standards and focuses on delivering determinism and convergence of multiple data traffic streams on one network. Two particularly important TSN sub-standards that provide such abilities are IEEE 802.1 AS and IEEE 802.1 Qbv.
The first ensures that all devices on a network are synchronized, providing the basis for determinism. This synchronization of device clocks is at the tens of microseconds level. Once a shared sense of time is in place across a network, IEEE 802.1 Qbv defines “time aware shapers.” These define specific “time slots” that are assigned to different types of network traffic, which are prioritized according to the information carried. As a result, different types of data traffic can all travel across the network in a predictable way, further supporting deterministic communications. Ultimately, this method supports convergence of multiple traffic types and consequently the ability to combine the operational technology (OT) and information technology (IT) worlds.
What does this mean for end users, machine builders and automation vendors?
Simpler network architectures/machine designs
The capabilities discussed allow end users to reduce the number of networks required for their operations, as they can merge different data traffic streams together while ensuring determinism. This ability, in turn, allows machine builders to pass on cost reductions, as less equipment and engineering work is required to design, configure and install network systems. In addition, timescales for complete projects are reduced.
Greater process transparency and better management
The convergence supported by TSN strengthens data transfer across the enterprise, allowing end users to have greater process transparency. In effect, transparency is all about being able to extract more data from industrial processes and analyze it to gather meaningful information that helps to better understand factory floor operations. This insight can then be leveraged to optimize performance, productivity, efficiency and end-product quality.
By supporting the creation of single networks that transfer all types of traffic, it is easier to troubleshoot and identify any potential issues. Therefore, downtime associated with maintenance or repair activities can be reduced, while overall uptime can be increased. As a result, the entire end user’s manufacturing system can become more productive.
Better integration of OT and IT systems
By converging multiple types of data, TSN offers a key way to merge OT and IT. This convergence is at the heart of data-driven smart manufacturing, as it promotes innovation and collaboration by sharing and utilizing actionable information across the entire enterprise. Consequently, by embedding TSN capabilities within their products, vendors can deliver solutions with increased interoperability, along with the capability for device data to be visible across the enterprise via cloud connectivity.
The digital transformation in support of IT/OT convergence absolutely requires the interoperability and interconnectivity that the TSN technology provides. Open standardization and the ability to work with a multitude of information modeling standards organizations is imperative for end users to truly leverage all their disparate applications and devices in a solution-based architecture. End-users require seamless data integration among their enterprises, including with existing devices and networks. For example, standards like MTConnect, PackML and ISA S95 are crucial components.
Common architectures with TSN-based systems
Ethernet with TSN is Ethernet. All cables and typical architectures apply. Since this is a “newer” Ethernet, network segments and devices that leverage TSN will need the support of TSN capable network switches. However, as Ethernet, it supports all traditional types of traffic, such as TCP/IP. Data from cameras can coexist with communications with real-time servo control. Your architectures will likely involve islands of TSN, where the deterministic communications are network switch isolated to a piece of equipment or a production line. But as Ethernet, you benefit from the ability to communicate with all devices from your IT network.
The impact on security
In an open Ethernet world, security is achieved through the management of your devices, the management of your network and the ability to deploy security solutions.
Management of devices is enhanced through Ethernet with TSN by enabling a greater level of communications. Devices that have previously been isolated to control networks are now accessible for configuration or management without the need to reconfigure your communications. As standard Ethernet devices, many are leveraging common IT tools for management, such as Simple Network Management Protocol.
Management of your network is enhanced through the use of newer network switches that are TSN capable. These can fall into managed and unmanaged categories, depending on your level of IT involvement, but more capable switches will certainly deliver greater capabilities in network security.
Deployment of security solutions is enhanced. Since your control network is now a segment of your information network, albeit through TSN capable network switches, your Ethernet security solutions will now have many new devices to monitor and secure.
There are a variety of companies that are now supporting Ethernet TSN with their industrial Ethernet protocols. A collaboration, formed in 2022, www.TIACC.net, exists to deliver a common interoperability specification for automation product vendors. This technology is being implemented today, and for EOMs and machine builders, can be a significant competitive advantage.
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