Improved Connection: Single Pair Ethernet

What is Single Pair Ethernet?

Ethernet cables started out with four wires – two wires for transmitting data and two wires for receiving data. As with most technologies, improvements have been made over the years to speed and efficiency. With gigabit Ethernet the same cables are now able to transmit and receive data. This has opened the door for Single Pair Ethernet. Single Pair Ethernet uses two wires only and therefore thinner cable to combine input and output.

Single Pair Ethernet also has the capability to provide power through the cable - known as Power Over Data Line (PoDL). Traditional Ethernet also had this capability, Power Over Ethernet (PoE).

Single Pair Ethernet vs. Standard Ethernet

The cable reach of the traditional Ethernet is 100 meters, while SPE has a cable reach of up to 1,000 meters. This long cable reach, combined with high data rates enables Single Pair Ethernet to be used even on field level. Where current field busses like PROFIBUS, CC-Link, DeviceNet or CANopen are used, SPE has the potential to replace those systems to connect large robots as well as sensors, cameras and actuators. Instead of using many different systems, there is one communication protocol streamlining data from the sensor to the cloud to make communication simpler and faster. Gateways are no longer needed.

Additional advances over traditional Ethernet include:

• SPE connectors are much smaller than traditional Ethernet connectors
• SPE connectors have a larger contact plate versus the point to point connection from traditional Ethernet
• SPE connection is a simpler, one channel connection versus traditional Ethernet's four channels

Advantages of Single Pair Ethernet

There are many advantages to Single Pair Ethernet, but the most remarkable may be:

• 50% reduced cable weight and 30% reduced cable diameter
• Need of copper is reduced
• Smaller cable means more accessibility in tight areas e.g. robot arms
• PoDL up to 50W with IP 20 connector version and 200 W with hybrid version
• Combination of long cable reach (1,000m) and high speed (up to 1000 Mbit/s)