3Com S7906E - Switch, Configuration Manual

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interface is enabled with the PoE power management function (for the detailed description of the PoE
power management function, refer to Configuring PoE Power Management ).
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If the PoE interface is not enabled with the PoE power management function, you are not allowed
to enable PoE for the PoE interface.
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If the PoE interface is enabled with the PoE power management function, you are allowed to
enable PoE for the PoE interface (whether the PDs can be powered depends on other factors, for
example, the power supply priority of the PoE interface).
The PSE supplies power for a PoE interface in the following two modes:
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Over signal wires: The PSE uses the pairs (1, 2, 3, 6) for transmitting data in category 3/5 twisted
pair cables to supply DC power while transmitting data to PDs.
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Over spare wires: The PSE uses the pairs (4, 5, 7, 8) not transmitting data in category 3/5 twisted
pair cables to supply DC power to PDs.
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When the sum of the power consumption of all powered PoE interfaces on a PSE exceeds the
maximum power of the PSE, the system considers the PSE is overloaded (The maximum PSE
power is decided by the user configuration).
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Which PoE interface power supply mode is selected depends on the specifications of PDs. A PSE
can supply power to a PD only when the selected power supply mode is supported by both the
PSE and PD.
Follow these steps to enable PoE for a PoE interface:
To do… Use the command… Remarks
Enter system view system-view —
Enter PoE interface view
interface interface-type
interface-number
—
Enable PoE for the PoE
interface
poe enable
Required
Disabled by default.
Configure PoE interface power
supply mode
poe mode signal
Optional
signal (power over signal
cables) by default.
Configure a description for the
PD connected to the PoE
interface
poe pd-description text
Optional
By default, no description for
the PD connected to the PoE
interface is available.