The Benefits of Single Pair Ethernet for Industrial and Smart Building Applications

Developed for Industry

Single Pair Ethernet (SPE) is the new solution for connecting Ethernet-enabled devices in hard-to-reach locations. Given its unique cable structure, SPE is a key tool for introducing Ethernet into areas that have traditionally used other communication standards.

For many years, the structured cabling that forms the backbone of computer networking has used cables with 8 wires arranged into 4 twisted pairs. While the capabilities of Ethernet cables have evolved to increase speed and bandwidth, this basic design has proven itself reliable. Even after many years, it is still used for the latest enterprise networks.

However, conventional enterprise networks do not extend to the factory floor. With the increasing digitization of the industrial space, users need to connect existing machinery to the network, but many machines still use industrial bus communications, such as Profinet and Fieldbus. While these systems have delivered many years of reliable service, they now require conversion to connect to the Ethernet network, adding cost and complexity.

Understanding the IEEE Standards for Single Pair Ethernet

Single Pair Ethernet has been developed to replace older bus architectures with a unified Ethernet installation. Using cables and connectors that are smaller than standard Base-T Ethernet, SPE is designed to take Ethernet into places it was previously unable to reach. SPE is governed by the IEEE (Institute of Electrical and Electronics Engineers) within the broad 802.3 family of standards. These standards contain the physical layer specifications, such as line coding, modulation, and error correction, as well as operation parameters and compliance requirements.

SPE is not intended to replace existing Ethernet equipment in the field. There is a huge volume of cabling already deployed in existing infrastructure to support traditional Ethernet. To replace it entirely would be costly and time-consuming, with little overall benefit. Instead, SPE is designed to extend the existing Ethernet network. The result is a single network in which each node is equipped with an SPE connector and given its own unique IP address, creating seamless communication from the device to the cloud.

Single Pair Performance

The single pair construction of SPE is critical to its success. The first and most obvious benefits are derived from the physical design of the cabling. Single pair cables are smaller, lighter and easier to manage than traditional Base-T network cabling. They provide easy access into hard-to-reach or restricted locations, and the small size of the two-pole connector delivers space-savings of more than 50% in both panel and printed circuit board (PCB) installations.

Other benefits are less obvious, but no less important. The design of 4-pair Ethernet cables can result in crosstalk, as one pair of wires unintentionally interferes with its neighbor, limiting the maximum length of a Base-T network cable. In contrast, SPE cables are far less affected by crosstalk and can provide transmissions over considerably longer distances, up to a range of 1000 meters.

This longer range is vital in today’s Ethernet applications. Many modern installations are remote, in which equipment can be separated by considerable distances. Providing traditional Base-T networks over these larger distances requires the use of additional routers and switches to ensure secure communications. Instead, the greater range of SPE cables makes it far easier to connect devices in dispersed installations.

The single-pair design has an impact on performance in other ways. The use of the single pair architecture results in a compromise between high-speed and long reach. Some applications that require higher data rates, such as automotive and autonomous vehicles, do not require long cable lengths and can take advantage of the high-speed specifications, such as IEEE802.3ch. In contrast, many long-distance applications, such as those found in industrial and building automation, do not require high data rates and can make use of the 10Mbps performance of IEEE802.3cg which can extend up to 1000 meters.

SPE can also provide power over the same pair of wires to small devices. Power over Data Line (PoDL) frees the designer from the need to provide separate power connections, and SPE can deliver up to 52 Watts of power over its single pair of wires, greatly simplifying the installation of remote devices.

How SPE Simplifies Building Automation and Smart Device Integration

These capabilities have made SPE interesting to designers in a broad range of applications for which it was not originally designed. The benefits of Single Pair Ethernet in industrial settings are mirrored in several other industries. It has proved itself an ideal solution for the Internet of Things (IoT). The IoT relies on the constant transfer of large volumes of data, much of which is created by small and relatively simple devices such as sensors. The compact size, light weight and cost effectiveness of SPE makes it ideal for these small IoT-enabled devices.

The IoT is also playing a huge role in the future of building automation. The IoT brings together a huge range of sensors and devices into a Building Automation System (BAS) that monitors all aspects of a building’s operations. The need to connect so many discrete devices into the building network makes SPE hugely attractive for architects and installers. Its small size, ease of use and extended transmission distances, combined with its ability to deliver power to a range of devices, makes it ideal for use in BAS.

This is especially useful in smart buildings. SPE allows IP-based communication, which makes it easy to interact with other IoT devices in the smart building. While its bandwidth may be lower than traditional Base-T cables, it is more than enough for many of the low-speed applications that are found within building automation such as monitoring and environmental control systems.

Single Pair Ethernet and Zonal Architecture in EVs

SPE has also attracted keen interest from the automotive industry. The electronic systems within the modern vehicle are evolving rapidly, and manufacturers are constantly adding new features. The cable harnesses that deliver power, data, and control signals to systems throughout the vehicle are complex and heavy. This complexity affects the manufacturing process, and the weight of cable harnesses significantly impacts vehicle performance.

To address this growing challenge, the automotive industry is turning to a new concept known as zonal architecture. In contrast to existing structures, where systems are grouped together depending on their function, zonal architecture divides the vehicle into locations or zones. Each zone is managed by a controller that is responsible for all locally installed systems. The zonal controllers are close to the devices they manage so cable lengths remain short. The zones are connected using Ethernet protocols so that the vehicle resembles a conventional network.

In this application, SPE technology offers many advantages, not only allowing devices to integrate with established automotive Ethernet technology, but also reducing weight and bulk. The smaller size of SPE cables and connectors greatly reduces the size and weight of vehicle harnesses.

The Future of SPE

The adoption of Single Pair Ethernet is still in its early stages but is growing rapidly. Its key advantages of small size, light weight, and easy installation make it a highly attractive solution for businesses far beyond the industrial automation market. SPE will not replace traditional Base-T Ethernet, but will enhance it and take it to places previously off-limits.

Are you ready to explore how Single Pair Ethernet can transform your next project? Discover Cinch Connectivity’s innovative solutions designed to meet the demands of modern networking. From industrial automation to IoT, our products deliver the reliability and performance you need.

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