Application Guide

[144]
Software User's
Manual
–
Version 3.0
Configuration > PoE > Power Budget
Power Over Ethernet Configuration
Setting Description
Reserved
Power
determined
by
There are three modes for configuring how the ports/PDsmay reserve power:
1. Allocated mode: In this mode, the user allocates the amount of power
that each port may reserve. The allocated/reserved power for each
port/PD is specified in the Maximum Power fields.
2. Class mode: In this mode, each port automatically determines how much
power to reserve according to the class the connected PD belongs to and
reserves the power accordingly. Four different port classes exist and one
for 4, 7, 15.4, or 30 Watts.
In this mode, the Maximum Power fields have no effect.
3. LLDP-MED mode: This mode is similar to the Class mode except that
each port determines the amount of power it reserves by exchanging PoE
information using the LLDP protocol and reserves power accordingly. If
no LLDP information is available for a port, the port will reserve power
using the class mode.
In this mode the Maximum Power fields have no effect.
For all modes: If a port uses more power than the reserved power for the port,
the port is shut down.
Power
Management
Mode
There are 2 modes for configuring when to shut down the ports:
1. Actual Consumption: In this mode, the ports are shut down when the
actual power consumption for all ports exceed the amount of power that
the power supply can deliver or if the actual power consumption for a
given port exceeds the reserved power for that port. The ports are shut
down according to the ports priority. If two ports have the same priority,
the port with the highest port number is shut down.
2. Reserved Power: In this mode, the ports are shut down when total
reserved powered exceeds the amount of power that the power supply
can deliver. In this mode, the port power is not turned on if the PD
requests more power than available from the power supply.