User Guide

Technical Tip
DGS-1100-05PD
PoE Classication explained:
When a PD is connected to ports 1 and/or 2, the DGS-1100-05PD switch will request the PD’s classication during the
power-up and signature-detection process. Classication is an optional process. Some PDs do it, some don’t.
When a PD classies itself, it informs the switch of the maximum power that the switch should reserve for it. If a PD fails to
classify itself, the DGS-1100-05PD switch will default to Class 0 and assume the PD needs full 15.4 watts of power on that
particular port.
The following table illustrates Class 0, 1, 2 and 3 power limits.
Class Minimum PSE Power Maximum PD Power
0 15.4 W 12.95 W
1 4 W 3.84 W
2 7 W 6.49 W
3 15.4 W 12.95 W
Note: Class 4 involves higher power (802.3at) and is not supported on the DGS-1100-05PD ports 1 and 2.
Port 5
Port 1
PD Class Type Supported
Port 2
PD Class Type Supported
802.3af PoE Switch/Injector
Class 1 or 2 not supported
not supported Class 1 or 2
Port 5
Port 1
PD Class Type Supported
Port 2
PD Class Type Supported
802.3at PoE Switch/Injector
Class 0 or 3 not supported
not supported Class 0 or 3
Class 1 or 2 Class 1 or 2
When the DGS-1100-05PD is powered by an 802.3af switch/injector:
When the DGS-1100-05PD is powered by an 802.3at switch/injector:
The ability to pass-through PoE power to one or two downstream devices (PDs) is dependent on the PoE Classication of
those devices. The following tables show the DGS-1100-05PD switch’s capabilities when using PoE pass-through.