PoE power-on process falls into the following stages:
- Detection: The PSE detects whether PDs exist.
- Classification: The PSE grades PDs and determines power consumption of PDs. This stage is optional.
- Power-Up: The PSE supplies power to PDs.
You can adjust the parameters set for the previous stages and supply power to PDs of different types.
Configuration Condition
Before configuring PD power-on parameters, ensure that:
- The global PoE function is enabled.
- The interface PoE function is enabled.
Configure PD Detection Mode of an Interface
After the PoE function of an interface is enabled, the PSE detects the resistance capacitance between the power output wire pairs to determine whether PDs exist. The standard detection mode detects only PDs that comply with IEEE802.3af and IEEE802.3at. The standards define PDs and non-PDs, but there is a type of devices with resistance capacitance between those of PDs and non-PDs. The compatible mode can detect this type of devices.
Table 12-12 Configuring the PD Detection Mode of an Interface
Step
|
Command
|
Description
|
Enter the global configuration mode.
|
configure terminal
|
-
|
Enter the layer-2 Ethernet interface configuration mode.
|
interface interface-name
|
-
|
Configure the PD detection mode of an interface.
|
power detect-mode { compatible | standard }
|
Optional.
The default PD detection mode is the standard mode.
|
Configure the Interface Classification Mode
After the interface PoE function is enabled, the PSE detects the output current of the power supply to determine the power grades of PDs. Power is allocated to PDs according to the power grades of the PDs. PD classification is an optional step. You can skip the step by setting the non-classification mode.
Table 12-13 Configuring the Interface Classification Mode
Step
|
Command
|
Description
|
Enter the global configuration mode.
|
configure terminal
|
-
|
Enter the layer-2 Ethernet interface configuration mode.
|
interface interface-name
|
-
|
Configure the interface classification mode.
|
power class-mode { standard | never }
|
Optional.
By default, no classification is support.
|
![note](/storage/images/Document/Maipu/note-icon.jpg)
-
Some non-standard PDs may not support classification. This type of PDs are classified to class0 by default, and the maximum output power of the interface is 15.4 watt.
Configure Power-On Impulse Current Mode of an Interface
The PoE standard defines the PD power-on impulse current. The parameter is related to PSE, (parasitic) capacitance of the PD, and power of the PD. For the PDs that comply or not comply with the standard, the required power-on impulse current may be different. For different PDs, the related power-on impulse current mode must be configured.
Table 12-14 Configuring the Power-On Impulse Current Mode of an Interface
Step
|
Command
|
Description
|
Enter the global configuration mode.
|
configure terminal
|
-
|
Enter the layer-2 Ethernet interface configuration mode.
|
interface interface-name
|
-
|
Configure the power-on impulse current mode of an interface.
|
power power-up-mode { 802.3af | high | Pre-802.3at | 802.3at }
|
Optional.
The default power-on current mode is high.
|
Configure Power Line Pair of the Interface
PoE standard regulates two modes of power supply: idle line and data line pair. Standard PD needs to support two modes of power supply: signal line pair and idle line pair, but PSE only needs to support one of them.
Table 12-15 Configure the power line pair mode of the interface
Step
|
Command
|
Description
|
Enter the global configuration mode.
|
configure terminal
|
-
|
Enter the L2/L3 Ethernet interface configuration mode
|
interface interface-name
|
-
|
Configure the power line pair mode of the interface
|
power power-pair {pair-A | pair-B }
|
Optional
By default, the power supply line pair mode is data line.
|
![note](/storage/images/Document/Maipu/note-icon.jpg)
-
The PSE device only supports the data line power supply mode.
Configure the Power-off Detection Mode of the Interface
PSE switches can provide different power failure detection modes according to the current type of power supply, DC or AC.
Table 12-16 Configure the power-off detection mode of the interface
Step
|
Command
|
Description
|
Enter the global configuration mode.
|
configure terminal
|
-
|
Enter the L2/L3 Ethernet interface configuration mode
|
interface interface-name
|
-
|
Configure the power-off detection mode of the interface
|
power disconnect { ac | dc }
|
Optional
By default, the power-off detection mode is DC.
|
![note](/storage/images/Document/Maipu/note-icon.jpg)
-
The PoE function of PSE equipment is integrated into the switch, which supplies power by the DC mode, and only supports the interface power off detection mode DC.