Thanks, yes, it has a carrier, of high frequency, but they dont say how high.
They avoid referring to it (on all the time), as i guess, most comms lines dont do ON all the time..they have eg Manchester coding.
Also, it says what the infineon gate drivers say, and i have just had a reply from the official infineon forum saying they dont do 100% duty with any of their isolated gate drivers...this has blown my entire reality check totally out of the water on this subject. My compass on this is now just spinning round and round.