Internal and external POE at the same time

[filip wouters]

I've a customer who wants to connect a POE clientdevice on a POE-enabled switch (WS-X6148A-GE-45AF blade in a 6509 switch).

The device is an alarm system and even without network connection it will need to be powered because it needs to be able to do some local alarming (light and sound).

For redundancy reasons the customer wants to connect the device to an external POE-injector at the same time. He claims that the switch will detect the power of the external injector and will not provide power as long as this external power is present. And that the switch will autmatically take over when the extarnal source goes down.

Is this true?

And if this is true (and reliable) how do i need to configre the poe settings: auto, static or something other?

[Reza Sharifi]

So, this depends on how much power will this "clientdevice" draws. If the blade support UPOE that is up to 60 watts and POE+ up to 30. So, I would simply connect it to a port and see if it powers up and the device can function. It may just work with default setting in the port if not you would need static setting on that port.

HTH