A guide to PoE and why it's a smart choice for clocks and other small devices
You may already know all about Power over Ethernet (PoE) technology. You may be well-versed in the low power consumption, cost-effectiveness, and ease of installation for the hundreds of modern devices that utilize the technology, such as VoIP phones, webcams and other devices including Inova's OnTime digital clocks, analog clocks, and OnTrack X Series digital displays. But for those not familiar with PoE (read "P-O-E," not Poe as in Edgar Allen), allow me to review the basics.
What is Power over Ethernet, Anyway?
Power over Ethernet technology is a network standard that allows various devices, such as Voice over IP (VoIP) telephones, wireless LAN access points, clocks, and digital signs to receive both power and data over existing LAN cabling. In 2003, PoE became an international standard, called IEEE 802.3af, as an extension to existing Ethernet standards.
There is no need to modify your existing Ethernet switch equipment or cabling to support PoE. Simply add a midspan power injector in a switch room or endpoint to inject power into the twisted pair LAN cables. PoE is fully compatible with both powered and non-powered 10/100BaseT Ethernet devices, featuring a "discovery process" specifically designed to prevent damage to existing Ethernet equipment.
Since no AC outlets are needed to power devices, PoE offers significant time and installation cost savings. In fact, when Purdue University powered more than 1,000 access points with PoE power in 2003, they reportedly saved between $350 to $1,000 per access point by eliminating labor costs from contracting an electrician to run wiring for new AC outlets. For a large project such as Purdue's, the savings amount to hundreds of thousands of dollars or even millions. That's savings you can take to the bank (and maybe even earn you a promotion, or at least a congratulatory pat on the back).