Configuring the PoE Power, Priority, and Class
The PoE Settings page displays system PoE information for enabling PoE on the interfaces and monitoring the current power usage and maximum power limit per port.
This page limits the power per port in two ways depending on the Power Mode:
- Port Limit: Power is limited to a specified wattage. For these settings to be active, the system must be in PoE Port Limit mode. That mode is configured in the PoE Properties page.
When the power consumed on the port exceeds the port limit, the port power is turned off.
- Class Limit: Power is limited based on the class of the connected PD. For these settings to be active, the system must be in PoE Class Limit mode. That mode is configured in the PoE Properties page.
When the power consumed on the port exceeds the class limit, the port power is turned off.
In some cases, the switch does not have enough power to supply all ports with their allowed power at once. To resolve this problem, assign both limits and priorities to the ports. For example, 15.4W is allowed on all 48 ports, but only 24 ports can be supplied at one time due to power limits. In this case, the priority determines which ports receive power and which ports do not even though no port is above the limit and they all have PDs connected. These priorities are entered in the PoE Settings page.
See the Smart Switch Models table for a description of the switch models that support PoE and the maximum power that can be allocated to PoE ports.
To configure PoE port settings:
- Click Port Management > PoE > Settings (Port Limit). The PoE Settings page opens.
- Select a port and click Edit. The Edit PoE Settings page opens.
- Enter the value for the following field:
- Interface--Select the port to configure.
- PoE Administrative Status--Enable or disable PoE on the port.
- Power Priority Level--Select the port priority: low, high, or critical, for use when the power supply is low. For example, if the power supply is running at 99% usage and port 1 is prioritized as high, but port 3 is prioritized as low, port 1 receives power and port 3 might be denied power.
- Administrative Power Allocation--This field is displayed only if the Power Mode set in the PoE Properties page is Port Limit. If the Power mode is Power Limit, enter the power in milliwatts allocated to the port. The range is 0 to 15,400.
- Max Power Allocation--Displays the maximum amount of power permitted on this port.
- Class--This field is displayed only if the Power Mode set in the PoE Properties page is Class Limit. The class determines the power level:
Class
Maximum Power Delivered by Switch Port
0
15.4 watt
1
4.0 watt
2
7.0 watt
3
15.4 watt
4
15.4 watt
- Power Consumption--Displays the amount of power in milliwatts assigned to the powered device connected to the selected interface.
- Overload Counter--Displays the total number of power overload occurrences.
- Short Counter--Displays the total number of power shortage occurrences.
- Denied Counter--Displays number of times the powered device was denied power.
- Absent Counter--Displays the number of times that power was stopped to the powered device, because the powered device was no longer detected.
- Invalid Signature Counter--Displays the times an invalid signature was received. Signatures are the means by which the powered device identifies itself to the PSE. Signatures are generated during powered device detection, classification, or maintenance.
- Click Apply. The PoE settings for the port are defined and the Running Configuration file is updated.