How Single Pair Ethernet Brings Ethernet to the Edge

Single Pair Ethernet (SPE) has been gaining attention across industry over the past few years because of its ability to use thinner cabling (thus reducing space requirements) due to its use of just two wires versus the four wires used in standard Ethernet cables. It’s also  being recognized for its ability to offer up to 10x longer distance runs, 80x the bandwidth, and 2x the power of standard Ethernet.

As industry transitions toward Industry 4.0 and its all-digital communication requirements, the advance of SPE is well-timed. Automation World has been covering how industrial networks are increasingly becoming the center of automated processes, much as  controllers have long been viewed.

Mike Vermeer, engineering strategy manager, Panduit.“We tend to think of networks and controls as being separate things, but as we get to the edge on the industrial plant floors—the two are part of the same system,” says Mike Vermeer, engineering strategy manager, at Panduit, a supplier of electrical, industrial, and networking components. “In this regard, SPE devices are going to be part of the controls system design, but they will also have the Ethernet connection for monitoring, remote access, and data acquisition.”

Single Pair Ethernet explained.

As most Ethernet-connected devices on plant floors incorporate Ethernet managed switches and use multi-layer segmented networks, Ethernet programmable controllers and smart I/O distribution devices are now common elements of control systems, notes Mike Berg, senior business development manager at Panduit.

Mike Berg, senior business development manager, Panduit.But when you look at the edge of the network, “the majority of connections are to non-processor devices, such as analog devices, simple I/O, and sensors,” Berg says. “The SPE format has been designed for both IT and OT standards to provide communication, power, and extended distance cable runs for these type devices.”

Panduit’s SPE Shielded Copper Cable has 18/7 AWG stranded tinned copper conductors with foamed polyethylene (PE) insulation. The conductors are twisted in a pair and include two fillers. The pair is surrounded by an aluminum/polyester foil shield, a tinned copper braid shield, and includes a 24/7 AWG stranded tinned copper ground wire.SPE is already being used in the process industries because it allows them to bring Ethernet to intrinsically safe areas and simplify the network and power design, says Vermeer. One significant advantage to SPE seen by process industry users is “the ability for a single device to simultaneously support multiple protocols over SPE, for example OPC-UA, Profinet, and Foundation Fieldbus,” he says. 

Why networking technologies are acting more like the heart of automated processes.