editor's blog
Subscribe Now

Who Uses Power-Over-Ethernet?

Maxim recently released a reference board (called Pasadena) that implements power-over-Ethernet (PoE). As we were discussing it, I inquired about who is really using PoE. I mean, I’m familiar with it, and yet I hardly ever hear anything about it actually being used.

Figure.jpg

(Image courtesy Maxim)

They pointed out three specific target markets:

  • Wireless routers
  • Cameras
  • Point-of-sale (PoS… no, not that PoS) terminals. Cash registers, for most of us.

The top two share characteristics in that they’re likely to be positioned in some inconvenient place. PoS terminals… not so much. But they all a) need power and b) send data. So why not do both on the same wire?

This makes perfect sense, by definition, for a wireless access point. That device has no choice but to have a wired connection into the network. That’s what it does – aggregate wireless onto a wire. So might as well bring power in as well on that same wire if it can handle the load.

For the other two, the calculus depends on whether communication is wireless or not. Cameras have a lot of data to send, so a wire might make sense. But if it’s wireless, then it will still need a wire for power unless it can harvest (or take advantage of distance wireless power, which we’ll talk about soon… not clear it can provide enough power for this though). So, assuming PoE can provide the power, you can either use wired-communication-and-power or wired power/wireless communication. It’s a single wire either way.

Portable PoS terminals are typically wireless, but they don’t count because they’re also battery-powered; they get zero wires. So for fixed PoS terminals, you’ll always need at least one wire. If you’re using wired Ethernet, then you’ll need that – might as well bring power along for the ride (again, if there’s enough juice).In some cases, a Barnett Electrical panel upgrade is required.

Part of this is simply the logic that one wire is easier than two. While true, that understates the issue, because the two wires are not the same. Stringing Ethernet comes with far fewer code requirements than stringing 120 (or 240) V. One you can literally do yourself; the other requires an electrician. (Seriously, I know you’re a smart guy… hire an electrician anyway.)

All of this said, I certainly don’t have visibility into a lot of PoE actually being deployed. Feel free to comment below either if you or someone you know is deploying it or if there’s some other barrier that’s getting in the way.

There’s more info on the Pasadena board here.

Leave a Reply

featured blogs
Jul 20, 2024
If you are looking for great technology-related reads, here are some offerings that I cannot recommend highly enough....

featured video

Unleashing Limitless AI Possibilities with FPGAs

Sponsored by Intel

Industry experts discuss real-world AI solutions based on Programmable Logic, or FPGAs. The panel talks about a new approach called FPGAi, what it is and how it will revolutionize how innovators design AI applications.

Click here to learn more about Leading the New Era of FPGAi

featured paper

DNA of a Modern Mid-Range FPGA

Sponsored by Intel

While it is tempting to classify FPGAs simply based on logic capacity, modern FPGAs are alterable systems on chips with a wide variety of features and resources. In this blog we look closer at requirements of the mid-range segment of the FPGA industry.

Click here to read DNA of a Modern Mid-Range FPGA - Intel Community

featured chalk talk

Automotive/Industrial PSoC™ High Voltage (HV) Overview
Sponsored by Mouser Electronics and Infineon
In this episode of Chalk Talk, Amelia Dalton and Marcelo Williams Silva from Infineon explore the multitude of benefits of Infineon’s PSoC 4 microcontroller family. They examine how the high precision analog blocks, high voltage subsystem, and integrated communication interfaces of these solutions can make a big difference when it comes to the footprint size, bill of materials and functional safety of your next automotive design.
Sep 12, 2023
36,641 views