By Bob Voss
How single-pair Ethernet cabling will reduce the risks introduced by older communications protocols
By Bob Voss
They are in the ceiling and walls of your office. They touch all your production equipment. They are everywhere in your warehouse. They turn on the lights.
What am I talking about? Why, your automation networks, of course. And they need help.
Voice and data networks, the shiny stuff in the data centre, get refreshed aggressively, every three to five years in the data centre and every five to six years in enterprise.
Automation networks that control the profit-making assets or ensure the comfort and safety of building occupants have a more relaxed refresh rate – something along the lines of “every couple of decades,” if you are lucky. That is risky business, literally.
Here’s why you should be upgrading your automation networks:
1. The older protocols used in these networks, while built for purpose and well-designed, are slow and difficult to maintain.
Also, there is not one protocol to rule them all. HVAC systems like to speak BACnet, power meters are Modbus, variable speed drives are DeviceNet – you see where this is going.
This creates business continuity risk for two major reasons. First, the equipment manufacturers may have stopped or are about to stop producing repair parts. I have heard too many horror stories of control engineers trolling eBay trying to get an older machine back in the game.
Second (hint: look at my bio picture below), the knowledge to support/maintain these older disparate protocols is walking around in greying heads old enough to retire.
2. The right technology exists to address this issue.
The smart people who create engineering standards have created a new form of Ethernet called single-pair Ethernet (SPE).
In February 2020, IEEE published IEEE Standard 802.3cg-2019, “Physical Layer Specifications and Management Parameters for 10Mb/s Operation and Associated Power Delivery over a Single Balanced Pair of Conductors.”
For industrial and building automation networks, SPE is just what the doctor ordered. SPE is designed to support common automation network topologies – long-reach point-to-point communications, i.e. 10Mb/s at up to 1,000 metres, and multi-drop (trunk/spur) communications, i.e. eight nodes at a combined distance of 25 metres. Multi-drop also features 10Mb/s speed.
SPE is vital to automation networks because we don’t have to change the way we build machines, buildings or plants to gain Ethernet functionality.
3. It is an issue of significant size.
If you look at the machinery in a factory and count sensors, actuators, drives, contractors, motor starters, etc., there are an enormous number of connections at the network edge. Those connections are all old protocols that I discussed above.
Here is something a little more current. Panduit’s World Headquarters, a five-storey, 280,000 square-foot LEED Gold building, was commissioned in 2010.
The voice and data network used 600,000 feet of category cable. The automation cabling footprint, which would be SPE if we were designing that building today, is 500,000 feet.
Simple math says that the SPE opportunity is nearly as large as the voice and data network in the case of modern buildings. I will wager that older buildings with similar functionality have a much larger automation cabling footprint.
4. IIoT/Industry 4.0.
We all anxiously consume content describing the nirvana that awaits when we deploy these two concepts in our businesses. I totally agree. There have been some amazing pilot projects implemented using battery-powered wireless sensors.
I do not believe those pilots scale well because we would quickly get to a state where there is a maintenance tech dedicated to changing sensor batteries on a nearly continuous basis.
There is a conspicuous need for low bandwidth, easy-to-deploy, secure communications to make IIoT and Industry 4.0 function smoothly. Providing data plus power on a single cable makes a lot of sense. SPE is perfect for that job.
I am not advocating a total “rip and replace” for your automation networks. If I could convince businesses to do things that radical, I would be on Wall Street, not in an R&D group. Here are some takeaways I would like you to consider:
- SPE is “single-pair Ethernet.” Ethernet is the foundation of the internet for good reasons. It is the dominant physical layer for wired communications. SPE enables you to get Ethernet to the devices on at the edge of the OT network.
- SPE is “migration-friendly.” Because it supports cabling topologies we like to use, we can deploy it as we upgrade and repair. Or design it in when a greenfield project comes up.
- SPE is “one protocol to rule them all.” And happily, the younger workforce is very adept with Ethernet, so the looming business continuity risk is addressed.
- SPE simplifies the network edge. Because SPE features “optional power delivery,” to use the phrase from the IEEE standard, it is an enabler like Power over Ethernet (PoE) is for four-pair Ethernet networks. None of the legacy protocols in automation networks do that today. So, SPE has the transformative power to simplify edge networks by providing data and power in a single connection.
- SPE improves your cybersecurity posture. Legacy protocols use a technique called “security through obscurity.” You do not know what it is or where it is, so it is secure. Not really. And those who sneak into networks do not care about sensor readings. They want to exploit that vulnerability to gain access to higher levels in the network. Since SPE is Ethernet, it brings all the IP security features.
In short, this technology is very important and should be on your development roadmap.
Bob Voss is chair of the Ethernet Alliance SPE subcommittee and is a contributing member of the converged plant-wide Ethernet architecture team. He is also a senior principal engineer for Panduit corporate research and development.