PoE has two Power Injection Techniques:
Alternative A – Power is supplied via centre taps of 2 coupling transformer (connected across data pairs 1, 2 & 3, 6)
Power & Data Signals – Transmitted over 1, 2 & 3,6;
PSE supplies power & data over same pairs & PD is able to receive its power on unused pair/data pair.
Phantom Power: Power running on wire carrying data signal
Alternative B – Power is transmitted over unused pairs (4, 5 & 7, 8)
Power - Transmitted over 4, 5 & 7, 8
Data - Transmitted over 1, 2 & 3, 6
If the above mentioned schemes are right, how and based on what do I select the power transferring mode (Mode A/ B) for my application? This is quite significant for me, because only based on this, I would have to select my PSE (Power Sourcing Equipment).
Thank You.
