This week’s EYE on NPI (video) is a new twist on an old familiar classic – cables and components from Harting for a new implementation of Ethernet connectivity called “Single Pair Ethernet“. We’re interested in this because we have found that a lot of devices could benefit from a powered/wired network capability but Ethernet jacks are kinda huge and stiff – a single twisted pair cable could make wiring IoT devices easier and a lot less expensive because we don’t need nearly as many conductors – wire is not cheap! – and we don’t need a separate power adapter.
Ethernet was invented in the 70’s, and although it has been improved greatly, the underlying connector and cabling has not changed much. SPE is designed to be compatible with existing Ethernet installations, there’s going to be a translator chip, but the upper transport layers like TCP/IP will be the same. We’re actually big fans of Ethernet compared to WiFi – since there’s physical access you don’t have to deal with SSIDs, passwords, or enterprise management. That makes it ideal for IoT because one thing that’s super annoying about IoT products is deploying and updating when the WiFi credentials change. While we do see some IoT devices with Ethernet, it’s not as common as dropping in WiFi support. Perhaps, given that you still need to plug in power, SPE can make some headway into the industry.
The specifications allow for up to 1000 meter long cables, 1 Gbps data rate and 50 W power transmission. Not all at once though, for example 1 GBit/s is only up to a distance of 40 meters. There’s going to be some interdependence on those three stats that depend on the transmitter, receiver, and cabling quality. So there will probably still be 8-conductor Ethernet cabling for high speed + long distance configurations. In fact, when you look at the expected customer base from Harting, there’s a lot of infrastructure, robotics/automation, and monitoring, but no home or office computing.
The biggest customer right now for SPE is industrial automation – basically getting factories all wired over IoT. Factories don’t want to depend on a wireless network – heck we don’t even rely on WiFi when streaming our video show. SPE could be a nice upgrade from CAN where you’re still using 2 wires, but you get the benefit of Internet compatibility.
We think another group of products that will be popular with SPE is IP cameras, especially once one big vendor makes SPE products. Every facility has dozens of security cameras, and by definition they’re going to be really spread out over the building and grounds. That means the powering and wiring is going to be really annoying. With SPE, you can get power and data anywhere, over long distances.
Another really nice thing that SPE consortium came up with – you know how that little tab on the RJ-45 cable always breaks off? The connectors for SPE range from basic to waterproof varieties, and all of them are designed for secure latching with durable metal tabs!
Cool stuff to check out, specially for engineers working in automation and industrial technology, you’ll want to take a peek at the SPE specifications. There are many companies that are part of the SPE design specification, so you can be confident it will be a well-supported new spec.
Get started by picking up some cables and connectors at Digi-Key so that you can design SPE into your next product: visit https://www.digikey.com/short/zrvt71 to order Harting SPE connectors and have them in hand tomorrow!
Also see Harting’s video on SPE below.