Backup power source

hello all, we are using a NETRON EP4 with the latest firmware version with poe. Is it possible to use the 5V USB-Power-Source as backup if the switchport with poe fails? We are able to connect port A of the EP4 to the switchpack as well, so that data could be transmitted.

The 5V and POE can coexist, but you can’t send two inputs into the EP4, that will create a network loop and lock it up.
The port is a switch, not 2x Input.