Power over Ethernet (PoE) has become the colloquial term used to describe any technology that allows an Ethernet device to transmit and receive data, as well as receive power over the same cabling. The benefits of using the same cable for both data and power are numerous. It allows power to be delivered to small devices without having an electrician wire new circuits or a transformer to convert ac to dc—also referred to as a wall wart. It can also...