Allied Telesis AT-FS708/POE - Manual (Page 23)

AT-FS708/POE Fast Ethernet Switch Installation Guide
23
Power Budgeting The AT-FS708/POE Fast Ethernet switch provides a maximum power of
15.4 W per port on four of the eight ports for a total power consumption of
65 W, while at the same time furnishing standard 10/100 Mbps Ethernet
functionality. The AT-FS708/POE smart power management functionality
also supports any combination of Ethernet ports (1-8) that supply power
for IEEE 802.3af Class 0, 1, 2, or 3 powered devices up to a maximum of
65 watts, as described in Table 5.
Note
Power is supplied to the powered devices in the order that the ports
are connected or on a first-come-first-served basis until the 65 watt
limit is reached. If the switch is power cycled after the PoE devices
are connected to the switch ports, the power is supplied to ports 1
through 8 in that order.
Note
The Range of Power Levels Available at the PD Input reflect the loss
introduced by a 100 meter Ethernet cable between the Power
Source Equipment (PSE) and the Power Device (PD).
A port connected to a network node that is not a powered device (that is, a
device that receives its power from another power source) functions as a
regular Ethernet port, without PoE. The PoE feature remains enabled on
the port but no power is delivered to the device.
Table 5. IEEE 802.3af Class vs. Power Levels
Class Usage
Maximum Power
Levels Output at
the PoE Port
Range of Power
Levels Available
at the PD Input
0 Default 15.4W 0.44W to 12.95W
1 Optional 4.0W 0.44W to 3.84W
2 Optional 7.0W 3.84W to 6.49W
3 Optional 15.4W 6.49W to 12.95W