Single-Pair Ethernet, or SPE, is a new Ethernet connectivity standard for automating factories, processes, and buildings. It will make it easier to implement integrated strategies, like the Industrial Internet of Things, more quickly.

In this piece, we'll talk about what Single-Pair Ethernet is and how it works. We'll also talk about what you need to know before you can think about using SPE in your plant or facility.

1: Using one pair of copper lines for transmission
The first thing you need to understand is that "Single-Pair Ethernet" means that Ethernet is sent over only one pair of copper lines.

Up until now, Fast Ethernet at 100Mb required two pairs of copper wires and Gigabit Ethernet required four pairs of copper wires.

SPE changes the game, especially when it comes to connecting sensors and field devices. This simple two-wire setup can send up to 1 Gigabit/second of data.

2: PoDL is used to send power.
The next important idea is that Single-Pair Ethernet can also send power to end devices at the same time. This is called Power over Data Line, or PoDL.

Special wires and connectors make it possible to send both power and data over the same wire. There are different cable configurations and power capacities that can send up to 16A to devices that are plugged in.

3: Standards set by IEEE 802.3
IEEE 802.3 has made a new set of rules for Single-Pair Ethernet.

The process businesses need the IEEE 802.3cg standard the most. This standard explains 10Base-T1, or 10 Megabits/second Ethernet, which can run over a single twisted pair cable for up to 100 meters without signal loss.

Most important for workplace automation is IEEE 802.3bp. It is the standard with a faster data rate of 1 Gigabit/second but shorter lengths of up to 40 meters.

4: Protocols for Industrial Ethernet
Single-Pair Ethernet can talk over the most popular types of industrial Ethernet protocols, like Ethernet/IP, Profinet, and EtherCAT.

This lets control devices already in use, like PLCs, that use these industrial Ethernet standards connect to Single-Pair Ethernet subnetworks using SPE Field Switches.

5: Why Single-Pair Ethernet is a Good Idea
With SPE Field Switches and Ethernet-connected devices, IP communication can be brought down to the lowest level of automation, giving full visibility from sensors and controllers all the way up to the cloud.

Single-Pair Ethernet also has other benefits, such as lower wiring costs, lower node costs, less power use, and the ability to send data over a single pair of lines.

Engineers, techs, and workers all know a lot about IP technologies.

If you can use a single network type for all plant-level interactions, you won't have to learn the differences between many different types of networks.

6: Power over Data Line (PoDL) vs. Power over Ethernet (PoE): Power over Data Line (PoDL) is not the same as Power over Ethernet (PoE). The IEEE Standards 802.3af, 802.3at, and 802.3bt explain Power over Ethernet.

For PoE to work, you need a special network switch with one CAT5 wire connecting one device to each port. Power is capped at 350 milliamps for IEEE 802.3af. Power is capped at 960 milliamps for IEEE 802.3bt.

PoE has helped connect things like wireless access points, phones that talk over the internet, and monitoring cams.

Power over Ethernet can't be used to connect monitors or field devices at the plant level because of how the network works.

7: SPE vs. Ethernet APL
Ethernet APL and Single-Pair Ethernet are not the same thing. As was already said, the different kinds of Single-Pair Ethernet are defined by a number of IEEE Standards.

Advances Physical Layer, or Ethernet APL, is a type of Single-Pair Ethernet.

Ethernet APL works at 10 Megabits per second, which is called 10Base-T1L. L stands for "long distance," which in this case is 1000 meters.

Ethernet will be able to be used in places in manufacturing plants where it couldn't be used before if it could reach these lengths.

8: Wires, plugs, and cables
Single-Pair Ethernet devices can't be linked with regular CAT5E and CAT6 lines.

Standards IEC 63171-6 and IEC 63171-7 have been used to make sure that SPE devices can communicate with each other.

For SPE networks, automation providers like TE Connectivity are designing and making these new cable and connector configurations.

Using 4-pin M8 connectors or 6-pin M12 connectors, power and data are sent to the devices over a single wire.

With these quick-connect wires, you don't need cable glands, you don't have to take the sensor housing off, and you don't have to make screw terminations.

9: Topologies
Single-Pair Ethernet networks can be set up in different ways to connect devices and sensors, such as point-to-point (from a SPE switch to a device using a specialized cable) and multi-drop, which can connect up to eight different devices.

A multi-drop topology, like ProfibusDP and Foundation Fieldbus field networks, needs a terminating resistor at each end of each section.

Hybrid multi-drop connection technology will let machines, robots, and movable process tanks, just to name a few examples, connect to a network through a single point.

10: Sensors and gadgets for SPE
Several companies make SPE field network switches, but sensors and other devices that can use SPE are not yet on the market.

Many of the sensors made by big industrial companies like Endress + Hauser and Siemens have SPE interfaces, and many of them are currently being tested before they are released.

The Single-Pair Ethernet Industrial Partner Network is made up of a growing number of well-known automation providers. Over the next few years, these partner networks will help SPE get its goods out on the market.

11: Dangerous places
Electrically classified areas make it harder for automation engineers to make systems that can be used safely in dangerous places.

With the help of Single-Pair Ethernet and improvements in intrinsically safe barrier technology for communication networks, Ethernet can be brought to these plant-level places.

So, a single network strategy can be used in both the field and the cloud. Only the physical installation details need to be changed to fit the process setting.

Conclusion,
Using IEEE 802.3 Ethernet, Single-Pair Ethernet has the potential to provide fast, safe, secure, and reliable connection from the plant floor to the cloud.

There are many benefits, including lower costs, easier installation, uniform configuration across devices, and easier upkeep of instruments and automation technology.