Six advantages of single-pair Ethernet technology

As Single Pair Ethernet (SPE) gains more and more traction in industrial automation, it is important to understand the potential benefits this technology can bring to applications that need to transmit data over long distances but do not have extensive speed or bandwidth requirements. Now is the time to highlight the specific advantages of replacing four-wire wiring with two-wire wiring in terms of cost, installation and performance so that SPE can be used confidently in practice.

What is Single Pair Ethernet?

Simply put, single-pair Ethernet is a cabling configuration that uses a single pair of wires (or conductors) to transmit data at speeds of up to 10 Mbps (and potentially up to 1 Gb/s in the future). Designed for industrial users, this single-pair cabling can support up to 52 watts of DC power to cover a range of devices requiring power and data over distances of up to 1000 meters.

Single-pair Ethernet also provides reliable power (as opposed to wireless) for sensors that are fixed in a physical location and may not have their own power source.

Single-pair Ethernet is also referred to in the standard as "twisted pair." The term refers to the fact that a pair consists of a balanced pair of conductors, each carrying a different signal. The most common configuration is to twist the two wires together.

Single Pair Ethernet is designed to meet the specific needs of industrial manufacturing users who are OT professionals concerned with connecting low-speed devices such as sensors, actuators and relays, as well as access control and lighting applications.

For their use case, OT professionals wanted a simpler, low-cost and space-saving alternative to the ultra-fast 4-pair cabling structure that has become the dominant network technology for office, telecommunications and data centers. Due to technical reasons, one wire is not reliable, so a pair of wires is the simplest and most compact configuration.

OT professionals also need capabilities that complement their specific use cases, where data is often transmitted over long distances to sensors, actuators, and other types of connected devices common on the factory floor.

They also needed cabling that could be easily retrofitted into existing facilities. From a space perspective, single-pair Ethernet easily replaced existing two-wire systems and was compatible with terminal block style connections commonly found in industrial applications.

Quite possibly the most important benefit of Single Pair Ethernet is that it is a familiar protocol stack, known to most of the world. The end-to-end Industrial Ethernet network provided by Single Pair Ethernet eliminates the need for a multitude of proprietary protocols running on various fieldbuses.

6 advantages of single pair Ethernet technology:

1. Lower capital expenditure

IE (Industrial Ethernet) and SPE connectors are very similar to today's RJ45 and M8 D-coded connectors. Although three-quarters of the wires are removed in the SPE connector, additional filler material is used to maintain the round shape of the cable. Depending on the type of cable used, the cost savings between IE and SPE connectors range from 13% to 44%. When purchasing larger quantities of connectors, greater savings can be achieved.

However, in terms of capital expenditures, the most significant savings come from the new network topologies made possible by single-pair Ethernet. For example, eliminating gateways and relying on a single communications network can save more than $10,000 per gateway. SPE makes it more economical to integrate sensors and actuators into the network infrastructure.

2. Reduced weight and small footprint

Single-pair Ethernet technology allows for the use of more compact, lighter cables that are 50% lighter and take up 50% less space than traditional fieldbus cables. This saves valuable space inside the robot and on interior walls and floors.

Take electric vehicle production as an example to illustrate these savings. Design engineers are looking for ways to reduce chassis weight to offset the weight of the powertrain, such as batteries and electric motors. For example, some designers have explored ways to remove shielding materials from wiring harnesses within a car to reduce weight. SPE offers a potential solution for reducing weight in electric vehicles.

Single Pair Ethernet also plays a vital role in the retrofitting of electric vehicles. It is recommended that vehicles be returned to the factory every 10 years for refurbishment of the necessary electronics. The structure of the chassis does not change, so the thickness of the interior walls of the vehicle remains the same. SPE cables can reduce the amount of space required for installation. This weight advantage is in addition to the port density (two SPE ports = 1 RJ45 port), which supports more devices in older vehicles.

3. Quick installation and easy maintenance

SPE allows field devices, sensors and actuators to be easily integrated into existing Ethernet environments without the need for additional gateways and interfaces, thus enabling faster and easier installation. This reduces material and labor costs for new factory floors.

4. Simplify the network

Single Pair Ethernet (SPE) can bring automation systems and traditional industrial networks onto a single Ethernet network technology, delivering both power and data to devices. Because they are based on the Ethernet protocol, SPE devices often outperform fieldbus devices.

Migrating sensors and controls to Ethernet using SPE simplifies cabling and management and potentially eliminates dedicated network equipment, bringing IP communications to the lowest levels of automation.

With SPE, troubleshooting and troubleshooting become more standardized and accessible than the combination of fieldbus protocols and special decoders and terminals that even the most skilled technicians need to resolve performance issues.

5. Support IT/OT integration and Sensor to Cloud

The industrial environment of the future will require flexible and adaptable connectivity to keep up with growing demands.

SPE is one of the technologies that will enable IIoT, Industry 4.0, IT/OT convergence, and seamless data transfer from field-level sensors to the cloud. Together, these innovations create a smart manufacturing environment driven by single-pair Ethernet.

6. Environmentally friendly

Finally, SPE requires fewer natural resources, such as plastics and metals, to build Ethernet-based infrastructure and connect assets, helping companies reduce their carbon footprint and achieve ESG goals.

As Industry 4.0 evolves and the number of sensors and actuators connected to the factory backbone continues to grow, Single Pair Ethernet will become a simple solution to accelerate industrial automation.