I need to use Ethernet cable for communication between controllers and also for PoE purpose. but I don't know exactly how to implement it? i mean is that need any extra circuit for that. or can i directly use two pairs of cable for message and another for power.
If your propose is that you want to have a Ethernet between to controller so you can use TCP/IP protocol please review this: https://www.edaboard.com/threads/115684/