Industrial ethernet - Powering the dream

Abstract

Power over Ethernet (PoE) brings a host of benefits to the design, implementation and long-term usability of wired Ethernet local area networks (LANs). Cost, flexibility and even safety are all enhanced. It overcomes the major limitation that system designers often encounter whereby they must locate powered network devices within close proximity to AC power outlets. With PoE, both data and power at a safe nominal 48VDC are carried over the same Ethernet cable. To take full advantage of PoE, the network devices will also be required to handle the hand-shaking process that allows the network hub to recognise a device as being PoE enabled and understand and manage its specific power needs.