Users Guide

Switch Feature Overview 83
PoE-capable switches that are connected to another PSE supplying power will
stop supplying power on the affected ports. PSE capability should be disabled
when connecting Dell EMC PoE enabled ports to other PSE equipment.
Powered Device Detection
The switch is capable, based upon configuration, of detecting legacy, AF, AT
or BT devices in two-pair or four-pair modes. BT/AT detection is initiated
first, followed by AF detection, and if configured, legacy detection. The
switch supplies limited power to the port during power up and prior to
performing detection. Only 802.3BT-capable switches are capable of BT
detection.
PoE Power Management Modes
PoE-capable switches can be configured to manage powered devices (PD)
using a dynamic, static, or class-based management. The power management
mode is configured using the power inline management command. Static
mode is not available on 802.3BT-capable switches.
Static Power Management
In this mode, the power reserved for the port is the configured limit regardless
of whether the port is powered or not. The device may draw up to the
configured limit. This mode is useful for devices that do not support
LLDP-MED.
Available Power = Power Limit of the Sources – Total Configured Power
The total configured power is calculated as the sum of the configured power
allocation for each port. Static mode reserves maximum power for the port,
for example, 30W for two-pair mode and 60W for four-pair mode, unless a
lower limit is configured by the administrator. Power is not reserved until a
PD is connected to the port. The powered device may draw up to the
configured limit. LLDP-MED packets requesting power are ignored in static
mode. Do not configure the powered device to use LLDP-MED to request
power in this mode.
Dynamic Power Management
In this mode, power is allocated based upon the detected PD class signature.
Available Power = Power Limit of the Sources – Total Allocated Power