10
W&T
IP-Watcher 2x2 Digital PoE
The external supply voltage for the device is always
1
required in networks not providing PoE, but may also be
used in PoE environments.
When powering with DC voltage, correct polarity is not required.
It is also possible to power the device with 12V DC. There
however you must take into account the very poor efficiency of
the power supply and the associated elevated current draw.
2.1.2 Voltage supply using PoE
The IP-Watcher is equipped for use in Power over Ethernet
environments per IEEE802.3af. The voltage is then provided by
the network infrastructure using the RJ45 terminal. The device
supports both phantom feed using data pairs 1/2 and 3/6 or
spare-pair power using the unused wire pairs 4/5 and 7/8.
To enable power management for the supplying components,
the IP-Watcher identifies itself as a Power Class 2 device with a
power draw of 3.84W to 6.49W.
With an external power supply the IP-Watcher can also
1
be used in networks not providing PoE support.
2.2 Network connection
The IP-Watcher provides an IEEE 802.3 compatible network
connection on a shielded RJ45 connector. Pin assignments
correspond to an MDI interface (see figure), so that connection
to a hub or switch is made using a 1:1 wired and shielded patch
cable.
1=
TX+
/
V+
2=
TX-
/
V+
3=
RX+
/
V-
4=
V+
8=
V-
7=
V-
5=
V+
6=
RX-
/
V-
Data line
Spare-Pair-Supply
Phantomsupply
Configuration of the RJ45 PoE network jack
