Hi....i suggest Ethercat - > 24 V PoE injector - > Esmacat(EASE) - > Arduino - > LED. It sounds to me like optocouplers and PoE have a comparable capacity in the arrangement as the PoE injector, yet they notice that the injector is on the grounds that EASE is fueled through 24 V Poe and Beckhoff gadgets may not be. I thought the explanation behind an optocoupler was to decrease the voltage from 24 V emerging from the KRC4 minimal to 5 V for the Arduino.