Term of the Moment
distributed antenna system
Redirected from: powered Ethernet
Definition: PoE
(Power Over Ethernet) Distributing power over an Ethernet network. Because the power and signal are on the same cable, PoE enables remote network devices such as ceiling-mounted access points, surveillance cameras and LED lighting to be installed far away from AC power sources. See PoE lighting and PoE switch.
Active vs. Passive PoE
Active PoE ports comply with IEEE standards and sense the power requirements of the target device. If older devices are not compliant, no current is delivered. In contrast, passive PoE switches send 24 volts without checking, forcing technicians to know the electrical requirements of the units they are installing.
PoE Injectors Add PoE to a Line
Industrial-Class PoE Switch
Active vs. Passive PoE
Active PoE ports comply with IEEE standards and sense the power requirements of the target device. If older devices are not compliant, no current is delivered. In contrast, passive PoE switches send 24 volts without checking, forcing technicians to know the electrical requirements of the units they are installing.
IEEE Max Power
Class Type Standard (Watts)
1 PoE 1 802.3af 15.4
2 PoE 1 802.3af 4.0
3 PoE 1 802.3af 7.0
4 PoE+ 2 802.3at 25.5
5 PoE++/UPoE 3 802.3bt 45.0
6 PoE++/UPoE 3 802.3bt 60.0
7 4PPoE 4 803.3bt 75.0
8 4PPoE 4 803.3bt 90.0
A PoE access point or camera is easily added to a regular Ethernet network with an injector, also called an "adapter."
This 8-port PoE switch from Omnitron Systems is a far cry from the common variety. It supports 10 Gigabit Ethernet as well as optical fibers (two SFP+ transceivers are plugged into the 10 Gbe ports). The switch accepts 12 to 57 volts of DC (top) and sends the exact amount of power required by the receiving device or none if not PoE enabled. If a connected device fails, that port can be remotely powered down. The DIP switches are used to configure the many options. See SFP.