The Benefits of Using Single Pair Ethernet for Industrial Automation

Learn about Single Pair Ethernet's benefits in industrial automation.
Single Pair Ethernet Benefits
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Back in the 1990s, Top Ten Lists were all the rage on television talk shows, and these lists, besides being entertaining, gave a glimpse into the chosen topic.

In this article, I will give you a peek into the world of single-pair Ethernet and the top 10 benefits it can bring to Industrial Automation.

Before we dive deep into the world of Single Pair Ethernet if you're thinking, How can I learn more about this exciting new technology?

Well, there's a great course called Single Pair Ethernet Fundamentals just for you. And if you're a RealPars Pro Member, you can jump right in and take the course.

Single-Pair Ethernet, or SPE, is a physical protocol. That means it describes, through a set of IEEE 802.3 standards, a method for physically connecting cables in a network using a single pair of wires.

You are probably familiar with standard Traditional Ethernet CAT6 cables which use 4 pairs of wires for communication, and perhaps Industrial Ethernet cables which use 2 pairs of wires.

Ethernet cables

Whether it is Traditional Ethernet, Industrial Ethernet, or Single Pair Ethernet, all are physical protocols that can transfer data using the same types of Ethernet communication.

So a Profinet communication network can be established using any of the three physical Ethernet protocols.

Server-to-sensor simplified

A hint of the first benefit was just mentioned: the ability to use a communication protocol like Profinet over any of the physical Ethernet protocols.

This simplifies the overall network design by allowing the same physical SPE protocol to be used regardless of the communication protocol being used.

Single Pair Ethernet networks require only a single cable for both data and power, making the overall cabling infrastructure more straightforward and less bulky.

By using a common infrastructure for all network devices and cables, there are fewer parts to stock, a shorter learning curve for maintenance personnel, and a shorter design time for new and upgraded installations.

Simplified network with SPE

Space savings

As you can imagine, this simpler network and cabling design takes up less space. Since power and communications signals can be carried over the same cable to each sensor, the number of cables that need to be installed is cut in half.

This translates into fewer conduits or cable trays. Only a single control panel is required to supply the necessary sensor power and make the communication connection at a common SPE switch.

Single Pair Ethernet networks can be constructed to connect devices and sensors in a number of different topologies, including point-to-point (from an SPE switch to a device using a dedicated cable) and multi-drop for connecting up to eight separate devices.

Multi-drop configurations can also greatly reduce the number of long runs of cable back to a central control cabinet by allowing up to eight sensors to be connected in a daisy-chain fashion.

SPE _ Space savings

SPE cable: easy install

Cables as defined by Standards IEC 63171-6 and IEC 63171-7 have been developed for SPE to ensure interconnectivity between SPE devices.

Automation suppliers, such as TE Connectivity, are engineering and manufacturing these new cable and connector configurations to support SPE networks. Power and data are delivered to the devices over a single cable using familiar 4-pin M8 connectors or 6-pin M12 connectors.

These quick-connect cables eliminate the need for cable glands, removing the sensor housing, and making screw terminations.

SPE cable

Cost savings

From the first three benefits of simplicity, space savings, and ease of installation, it is not hard to understand that there would be significant cost savings in employing SPE networks in industrial automation.

Fewer cables and small connectors make SPE installations lighter and less bulky. This can reduce the load on cable trays, allowing for less expensive support structures.

Combined with a smaller cabling footprint and a multi-drop installation, less physical space is required for SPE in the manufacturing space. This may allow for more equipment or devices to be installed inside the same square footage, saving capital for facilities.

Lastly, the labor savings from the above benefits and from the use of M8 and M12 connectors versus having to individually terminate cables can save the project a significant amount!

Longer cable reach & runs

SPE can reach longer distances than traditional Ethernet without the need for additional repeaters or switches, which is useful in expansive industrial environments.

The 10-BASE-T1L version of SPE covered by standard IEEE 802.3cg provides for cable lengths of up to 1000 meters at a data communication rate of 10 Megabits per second.


Increased data speed

SPE can communicate faster than traditional Industrial Ethernet protocols.

The 1000-BASE-T1 version of SPE covered by standard IEEE 802.3bp provides for cable lengths of up to 40 meters at a data communication rate of 1 Gigabit per second.

This version of SPE will become tremendously useful for devices, such as robots, that require a high rate of communication and the simplicity and compactness of SPE.


Integrated power

I mentioned in the discussion of the simplicity of Single Pair Ethernet that both power and data can be transmitted over the same cable to field devices.

In fact, with 10-BASE-T1L mentioned previously, up to 8 amps of power can be transmitted over an IEC-63171-6 compliant SPE cable. This cable type uses one pair of wires for communication and one pair of wires for power. This configuration is called Power over Data Line, or PoDL.

Stronger in harsh environments

SPE can offer better resistance to Electromagnetic Interference, commonly referred to as EMI, than traditional Ethernet which is crucial in industrial settings with a lot of electronic devices. SPE cabling is shielded, which assists in its EMI resistive properties.

SPE is also being developed and designed for robust performance, making it suitable for the harsh conditions often found in industrial environments, including resistance to EMI, heat, and moisture.

Enables IIoT and Industry 4.0 for the future

The Industrial Internet of Things, or IIoT, is a part of the Industry 4.0 strategy to connect sensors, instruments, and autonomous devices through the Internet to industrial applications. The simplicity and scalability of SPE make it ideal for connecting to this vast array of devices.

With the rise of Industry 4.0, the demand for even more interconnected devices and data-driven decision-making is growing. SPE ensures that industrial environments are prepared for these future requirements.

Standardization for interoperability

SPE is governed by a comprehensive set of standards. The physical protocol is governed by several different subsections of IEEE 802.3, of which IEEE 802.3cg and IEEE 802.3bp have been mentioned in this article. Cables used in SPE applications are described by IEC 63171.

These and other emerging standards will help ensure that sensors, actuators, and other devices produced by various manufacturers will all be able to work with one another out of the box.


There you have it: the top 10 benefits of using Single Pair Ethernet in Industrial Automation! Single Pair Ethernet can offer a combination of simplicity, scalability, and performance.

As industries continue to evolve towards more connected and data-driven environments, technologies like SPE will likely play an increasingly crucial role.

If you're eager to dive deeper and fully understand Single-Pair Ethernet, remember there's the Single-Pair Ethernet Fundamentals course waiting for you. If you're a RealPars Pro Member, you have direct access.

Thank you for your time, and happy learning.

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