HP PROCURVE 2520 Management And Configuration Manual page 262

Power Over Ethernet (PoE) Operation
PoE Event Log Messages
11-24
Port < port-# > PD MPS Absent indication.
The switch no longer detects a device on < port-# >. The device
may have been disconnected, powered down, or stopped
functioning.
Port < port-# > PD Other Fault indication.
There is a problem with the PD connected to the port.
Port < port-# > PD Over Current indication.
The PD connected to < port-# > has requested more than 15.4 watts
of power. This may indicate a short-circuit or other problem in
the PD.