![H3C S5120-SI Series Configuration Manual Manual pdf 716 page image](https://manuals-archive2.s3.amazonaws.com/3375400/6b95534c4ac31cac063c82b3e23ed663716f.jpg)
1-3Task Remarksthem, so noconfiguration isrequired.Configuring PoE Profile OptionalConfiguring PoE Interfacethrough PoE Profile Applying PoE Profile OptionalUpgrading PSE Processing Software in Service Optionalz Before configure PoE, make sure that the PoE power supply and PSE are operating normally;otherwise, you cannot configure PoE or the configured PoE function does not take effect.z Turning off the PoE power supply during the startup of the device might cause the PoEconfiguration in the PoE profile invalid.Enabling PoEEnabling PoE for a PoE InterfaceThe system does not supply power to or reserve power for the PDs connected to a PoE interface if thePoE interface is not enabled with the PoE function.You are allowed to enable PoE for a PoE interface if the PoE interface will not result in PoE poweroverload; otherwise, whether you can enable PoE for the PoE interface depends on whether the PoEinterface is enabled with the PoE power management function (for the detailed description of the PoEinterface power management function, refer to Configuring PoE Interface Power Management).z If the PoE interface is not enabled with the PoE power management function, you are not allowedto enable PoE for the PoE interface.z If the PoE interface is enabled with the PoE power management function, you are allowed toenable PoE for the PoE interface (whether the PDs can be powered depends on other factors, forexample, the power supply priority of the PoE interface).The PSE supplies power for a PoE interface in the following two modes:z Over signal wires: The PSE uses the pairs (1, 2, 3, 6) for transmitting data in category 3/5 twistedpair cables to supply DC power while transmitting data to PDs.z Over spare wires: The PSE uses the pairs (4, 5, 7, 8) not transmitting data in category 3/5 twistedpair cables to supply DC power to PDs.