There are power and data traveling over a single Ethernet cable in a standard PoE system. While the PoE system is not working, both power and data indicator is OFF. You can examine the power and data separately.
We will recommend you test the whole PoE power system before you go for installation in the field.
You can bring the edge device to the center and connect it to the PoE system with a patch cord. If the system is working, the PoE equipment is working.
Examine the connection. The connection properly is an easier place to go wrong. Please check each of the connections carefully.
There is always power loss inline. The longer the distance, the serious PoE power loss will be. You should pick the pure copper Ethernet cable and avoid the CCA which could generate serious power loss. You may see the power indicator keep showing on and off, using a shortage cable can verify the power loss issue.
The edge device should be IEEE802.3af/at/bt compatible device. While a non-PoE device is being connected at the edge, the PoE system will not release the power.