What is Single-Pair Ethernet (SPE)?

Traditional 2- or 4-pair Ethernet cables have been commonly employed in higher-tier systems across most automation applications. Due to their bulkier size and higher cost, Fieldbus is often favored at the lower level of automation for connecting sensors and actuators to PLCs, facilitating information exchange. The emerging Single-Pair Ethernet (SPE) technology utilizes a sole pair of copper wires for data transmission, reducing wiring weight and material costs, and offering a streamlined, cost-effective network connectivity solution. This method also supports the transmission of power and control signals over Ethernet networks, aiming to simplify Ethernet installations by using only one twisted pair.

Benefits of using Single-Pair Ethernet over Fieldbus:

• IP-based communication from the field site to the cloud, employing a uniform protocol standard.
• Bi-directional data flow, with faster transmission rates compared to Fieldbus systems.
• Support for Power over Data Line (PoDL, IEEE 802.3bu), enabling the provision of power to end devices.
• Cost-effectiveness by eliminating additional costs previously associated with connecting Fieldbus to standard Ethernet at higher levels.
• Continued use for existing 2-pair Ethernet infrastructure without requiring significant rebuilding efforts.
• Lightweight and space-saving design, making it suitable for interconnecting sensors and actuators.

Standards set by the IEEE 802.3 working group for SPE:

Equipment and speed requirements for devices using SPE

Potential application markets

Building Automation

Factory Automation

Elevator Control

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