As network technology becomes increasingly important to operate
security systems, and affordably priced Internet protocol (IP)
cameras and video management systems (VMS) are used more often,
system designers and installers, such as electrical contractors,
are realizing the need and efficiency of using power over
Ethernet (PoE). First used for voice over IP (VoIP) telephones,
PoE has gained popularity as a means of safely allowing power,
along with data, to pass on Ethernet cabling. “PoE voltage is
48V DC and sourced from an injector, midspan or switch, which
provides power. A PoE source will only provide the necessary
power when it recognizes the class or signature of a compatible
network device so that, in the event a non-PoE IP device is
inadvertently connected, the PoE source will not provide power
and damage the device,” said Ronnie Pennington, national
accounts manager for Altronix Corp., Brooklyn, N.Y. From VoIP in
the 1990s, PoE is now migrating to powering security system
components, such as IP camera