Poe (Power Over Ethernet) - TRENDnet TI-PG1284i User Manual

TRENDnet User's Guide
Parameter Description
State
Select this option to enable / disable the Modbus on the Switch.
Apply Click Apply to save your changes to the Switch.
Refresh Click Refresh to begin configuring this screen afresh.

PoE (Power over Ethernet)

Power over Ethernet or PoE technology describes a system to pass electrical power
safely, along with data, on Ethernet cabling. PoE requires category 5 cable or higher for
high power levels, but can operate with category 3 cable for low power levels. Power can
come from a power supply within a PoE-enabled networking device such as an Ethernet
switch or can be injected into a cable run with a midspan power supply.
The original IEEE 802.3af-2003 PoE standard provides up to 15.4 W of DC power
(minimum 44 V DC and 350 mA) to each device. Only 12.95 W is assured to be available
at the powered device as some power is dissipated in the cable.
The updated IEEE 802.3at-2009 PoE standard also known as PoE+ or PoE plus, provides
up to 25.5 W of power. Some vendors have announced products that claim to comply
with the 802.3at standard and offer up to 51 W of power over a single cable by utilizing
all four pairs in the Cat.5 cable. Numerous non-standard schemes had been used prior to
PoE standardization to provide power over Ethernet cabling. Some are still in active use.
PSE: Power sourcing equipment (PSE) is a device such as a switch that provides ("sources")
power on the Ethernet cable.
PD: A powered device (PD) is a device such as an access point or a switch, that supports
PoE (Power over Ethernet) so that it can receive power from another device through a
10/100 Mbps Ethernet port.
© Copyright 2016 TRENDnet. All Rights Reserved.
Standard PoE parameters and comparison
Property 802.3af (802.3at Type 1)
Power
available at 12.95 W
PD
Maximum
power
15.40 W
delivered by
PSE
Voltage
range (at 44.0 - 57.0 V
PSE)
Voltage
37.0 - 57.0 V
range (at PD)
Maximum
350 mA
current
Maximum
cable 20 Ω (Category 3)
resistance
Power Three power class levels
management negotiated at initial connection
Dreading of
maximum
cable
None
ambient
operating
temperature
TI-PG1284i
802.3at Type 2
25.50 W per mode
30.00 W per mode
50.0 - 57.0 V
42.5 - 57.0 V
600 mA per mode
12.5 Ω (Category 5)
Four power class levels negotiated at
initial connection or 0.1 W steps
negotiated continuously
5°C with one mode (two pairs) active,
10°C with two modes (four pairs)
simultaneously active
100