Transition Networks N-GXE-POE-LC-01, User Manual, Page: 15 / 34

Transition Networks N-GXE-POE-xx-01 User Guide
33599 Rev. E https:/www.transition.com Page 15 of 34
802.3af Classification
A PD can optionally present a classification signature to the PSE to indicate the maximum power it will
draw while operating. The IEEE specification defines this signature as a constant current draw when
the PSE port voltage is in the VCLASS range (between 15.5V and 20.5V), with the current level
indicating one of five possible PD classes. For example, a typical PD load line, starting with the slope of
the 25k
Ω signature resistor below 10V, then transitioning to the classification signature current (e.g.,
Class 3) in the VCLASS range. The table below shows the possible classification values:
Class Result
Class 0 No Class Signature Present; Treat Like Class 3
Class 1 3W
Class 2 7W
Class 3 13W
Class 4 25.5W (Type 2)
DC Disconnect
DC Disconnect detection involves measurement of current. A disconnected PD stops consuming
current, which can be inspected by the PSE. So the PSE must disconnect power within 300 to 400 ms
from when the current flow stops.
DC modulation allows a PD to draw a minimum current so it can not be identified as disconnected. With
DC modulation implemented, the PD can consume no current (and no power) for approximately 80% of
the time and still remain powered.
N ‐ GXE ‐ POE Behavior when PC enters a specific Power State
Various PCs support various level of sleep. You may need to configure sleep levels to work with the
NIC.
System Power State N-GXE-POE
ACPI
State Power State POE power NIC Ports with
WOL disabled NIC Ports with
WOL enabled
S0 Working Available Available Available
S1 Sleep (CPU clock/Bus clock are off) Available Available Available
S2 Sleep (Processor off/System cache
lost)
NA NA
Available
S3 Sleep(Processor off/Portion of Mother
board off)
NA NA
Available
S4 Hibernate NA NA Available
S5 Soft Off NA NA Available
G3 Mechanical Off NA NA NA