The general meaning of Power over Ethernet (PoE) is the capability of passing electrical power along with a data signal over the same Ethernet cable. This can be a pretty useful arrangement, since it requires only a single cable to provide both the electrical power and the data to receptors like Access Points (APs) and devices like IP cameras.

Active PoE

Active PoE is the standard, and it is what is assumed when anyone mentions 'Power over Ethernet', or PoE. The big advantage of PoE is that it allows greater flexibility in locating your Access Points, since they don't have to be situated near a power source - power is carried to them right in the Ethernet cable. That also frequently results in significantly lower installation costs, especially where many Access Points must be setup.

What makes Active PoE work is a Cat-5 injector, which injects a DC voltage into the Cat-5 cable, and is then typically accepted at the terminus by a wireless Access Point through its RJ-45 jack. Devices like these which can directly accept the injected power in the line are considered to be 'PoE compatible', and those which are not PoE compatible must be converted to compatibility by a PoE splitter.

PoE+

PoE+ was the original name of cabling standard 802.3at, which differs from active PoE, described in standard 802.3af. The main difference between these two standards is in how much power is provided over the cabling. With 802.3af (PoE), a maximum of 15.4 watts of power is provided, while (PoE+) could provide as much as 30 watts of power.

Passive PoE

Passive PoE is, as you might think, very similar to active PoE, with one notable exception. In active PoE, the switch and the remote equipment actually communicate and negotiate the proper voltage and the pins to use for the transfer of electrical power. In passive PoE, no negotiation takes place between the two devices.

NC-LINK PoE and Passive PoE Devices

NC-LINK provides both PoE and Passive PoE devices, include Ceiling Access Points, In-wall Access Points, Indoor & Outdoor CPEs, Switches. Passive PoE is all compatible with 24V. And all standard PoE switch compatible with 802.3af and 802.3at standard.