You don't need power injector between hEX S and OmniTik if you connect OmniTik to ethernet port 5 of hEX S (which is PoE out capable). Power adapter, supplied with hEX S (24 V, 1.2A) should be good to power both devices (each consumes max 11W, combined 22W or 0.9A @ 24V). I know this, the question ...