Single-Pair Ethernet Helps Industrial Designers Update and Build Systems for Industry 4.0
These simplified, yet powerful SPE connectors will help integrate equipment and buildings into a powerful, data-rich Industrial Internet of Things.
The standardization of single-pair Ethernet (SPE) in 2019 enabled designers of industrial architectures to envision new levels of power, data speeds, and reliability for manufacturing facilities, building automation systems, and transportation networks. The IEEE 802.3cg-2019 standard defines 10Mb/s Ethernet power and data over a “Single Balanced Pair of Conductors.” It lists two medium dependent interface (MDI) connectors, IEC 63171-1 and IEC 63171-6. The IEC 63171-6 connector, based on HARTING’s T1 Industrial connector interface, features a single twisted pair of copper wires that can deliver up to 60W of power over data lines (PoDL) and data transmission speeds up to 10Gb/s to connect individual elements within a network, as well as connect that network to the cloud. A second SPE connector family, introduced by Weidmüller, defines six connectors with different mating faces for industrial applications.
The SPE ecosystem is still in evolution; issues surrounding open cabling standards and the standardization of the T1 interface are still in progress. However, the concept of SPE has already been adopted by automotive designers in the 100BASE-T1 and 1000BASE-T1 standards. Industrial and building networks are next. Three industry groups, the Ethernet Alliance, the Single Pair Ethernet System Alliance, and the SPE Industrial Partner Network, are working with entities across the electronics industry, government, and universities to expand awareness about the advantages that SPE offers to industrial architectures.
SPE’s compact, lightweight form factor cuts cabling costs and bulk in industrial applications. “For plant engineers, SPE makes work easier. Installation is simpler compared to four-pair Ethernet and allows a noticeable reduction is space and weight,” said Jörg Scheer, head of the device and field connectivity division at Weidmüeller.
With origins in automotive Ethernet, where SPE is replacing CAN and other bus systems in driver-assist and autonomous applications, this rugged interface is capable of preventing the ingress of liquids and debris and enduring temperature extremes, shock and vibration, and outdoor conditions. Although industrial RJ45s continue to have wide utility in industrial and building networks, sensors have become critical to these increasingly automated systems, and a smaller connector is required to integrate them. SPE connectors achieve this goal and offer a host of cloud-based benefits as well. As Industry 4.0 and the Industrial Internet of Things (IIoT) bring greater levels of automation to industrial networks, SPE will become an integral part of new industrial architectures.
“SPE will bring Ethernet and power down to the plant floor level utilizing power over data line technology. This will mitigate the need for different communication protocols for control rooms, all the way down to sensors and devices, and that will allow for much faster commissioning time for field devices,” said John DeSouza, HARTING America’s president and CEO.
A variety of SPE connectors are already available from or are actively being developed by suppliers including HARTING, Amphenol ICC, Phoenix Contact, Rosenberger, TE Connectivity, and Weidmüeller, some of which support IEC 63171-6 Industrial Ethernet standard and IEC 63171-2 variant for IP20 environments and the IEC 63171-5 variant for IP67 environments. Additional companies, including Hirose Electric and Molex, are also part of industry efforts to further advance SPE technology.
“We see SPE as an enabling technology. SPE enables you to get Ethernet to more places faster and easier. It gives us the ability to use structures you’re familiar with and cabling you’re familiar with, and bring them to building and industrial networks,” said Peter Jones, chair of the Ethernet Alliance, and distinguished engineer at Cisco. (Jones was chair of the NBASE-T Alliance from its inception until its merger with the Ethernet Alliance.)
SPE will be an easy choice for new industrial architectures, but the adoption of the standard for existing facilities will be an ongoing process, says Jones, as architectures still based in fieldbus protocols move into the next industrial evolution. “In many instances, SPE will bring connectorization into environments where it’s still screw terminals or punch-down blocks,” he said. “SPE allows designers to adopt these connectors to get the benefits of Ethernet without having to rewire their entire facility.”
As operational technology engineers become familiar with the ways in which SPE can help optimize control systems and enable them to run more efficiently, the new interface will become a logical solution for updating and expanding existing protocols with a faster, more secure topology.
“The consolidation of power and data transmission into a single wire pair achieves significant space savings,” said Guadelupe Chalas, product manager, medical and industrial products, Rosenberger. Unshielded variants of SPE are about half the width as standard RJ45 connector solutions, while industrial products based on automotive offerings are about two-thirds the width of a standard RJ45. Industrial SPE solutions are also based on Ethernet and transmission protocol/internet protocol (TPC/IP), which allows for compatibility with existing cabling infrastructure.”
Bob Voss, senior principal engineer at the Caveney Innovation Center for Panduit, is the chair of the SPE subcommittee for the Ethernet Alliance. The SPE subcommittee includes representation from a broad range of Ethernet Alliance member companies. “From a control engineering standpoint, I look at what’s possible, and I get excited. But SPE is not limited to industrial automation. It will add value to all forms of OT networks – industrial, buildings, and IoT/Industry 4.0. As IIoT networks capture and transport more information, you can make better decisions — or quicker decisions — because you’ve got a richer data stream. SPE helps get that information in a less expensive way. When you have additional information, you can make things run better. With that information, I can deliver, for example, 2% more productivity, or 5% lower waste, or other measurable, meaningful goals,” he said. “With SPE, you can build factories, buildings, or machines the way you prefer and gain the capability of Ethernet. You can work with systems you already have. You’re not morphing the way you do business to conform with what Ethernet can do, SPE brings Ethernet to you. This broad spectrum of capability is augmented by the confidence of early connector standardization. During the creation of the IEEE 802.3cg standard, IEEE endorsed two SPE connectors, IEC 63171-1 and IEC 63171-6.”
In industrial settings, SPE will enable designers to quickly and easily connect sensors, cameras, actuators, and field devices, integrate time-sensitive network capabilities into systems, increasing the determinism of OT networks, reducing the amount of cabling required, and making the construction and maintenance of facilities easier and more cost-effective. SPE connectors can also bring these advantages to robotics, machinery, and vehicle applications including rail systems.
As SPE becomes standardized and more widely available, engineers working in industrial architectures will be able to further extend its potential. Jones notes that as the interface becomes a greater force in building and industrial automation, input from experts in the cable world, the automation industries (e.g., process control), and test and measurement will continue to push its evolution.
“The value in SPE is less about what you deploy as infrastructure and more about the value SPE creates,” said Voss. “There is going to be differentiation, such as performance-differentiating cable designs. But the top two Ethernet-based industrial protocols today are Ethernet IP and PROFINET. Those two together make up more than a third of the industrial Ethernet marketplace. The benefit in SPE is both of those will go across the same SPE infrastructure. We see similar dynamics in building automation with the move from BACnet/MSTP to BACnet/IP. SPE as infrastructure supports the control systems for today and tomorrow.”