Power Over Ethernet (Poe) - Iwatsu ICON Series IX-5910 Owner's Manual

POWER OVER ETHERNET (P E
)
O
Very Important! Power over Ethernet is supported ONLY if the PoE
switch is a UL listed "Limited Power Source".
PoE is supported for the Iwatsu ICON Series IP Telephones, Iwatsu
Platinum Series IP Telephones, IX-12IPKTD-E (December 2004 production
models and later), the IX-6IPKTD-E, and the IX-12IPKTD-E2 IP
Telephones. The IX-12IPKTD does not accept PoE.
The primary power source for the IP Telephones is derived from an IEEE
802.3af compliant LAN-based (Power over Ethernet-PoE) power supply.
For example: Your home telephone is powered from the Central Office
through the same twisted pair that carries your voice, now the same can be
done for Ethernet (IP) devices.
There is no need for every IP telephone to have a separate power supply.
Power is carried over the Ethernet using either a Mid-Span Ethernet Hub or
an End-Span Ethernet Switch. The IP Telephones will accept power from
either source.
The Power Sourcing Equipment (PSE) provides 48 VDC and 120 mA to the
telephone and runs a "discovery process" to examine the Ethernet cables
looking for devices that comply with the 802.3af specification. This
discovery process enables standard, non-standard, and un-powered Ethernet
devices to be connected on the same Ethernet infrastructure without special
wiring or device configurations.
A small current-limited voltage (via a UL approved "Limited Power Source"
Power over Ethernet Switch) is applied to the cable during the "discovery
process" to check for the presence of a 25k ohm resistor in the remote
device. Only if the resistor is present is the full 48 V applied. This is current-
limited to prevent damage to cables and equipment in fault conditions. The
powered device must draw a minimum current. For example: When the
device is unplugged, the PSE removes the power and the "discovery
process" begins again.
IP TELEPHONE USER GUIDE - 122