How do I recognise ack-messages?
I am building my own controller (in Python) and although most of it seems to work now, I haven't built functionality that resends not-acknowledged messages yet. I am planning to do so, but I can't find any documentation about how I can recognise an "acknowledged"-message. I know how to send one, but I don't know what I'm expected to receive back as acknowledgment.
Some tests show me that the controller literally repeats the message when that was sent by the controller, but before I start building, I would like to know if this is indeed how these messages were designed.
TL;DR - Is my assumption correct that messages with an ack-request are replied to with an exact copy of that message?
Yes, your assumption is correct.