thank you. yes however fdcan is fully backwards compatible with can / bacan which was my interest, i want to mix the two, i mean my solution needs g431 and f103 and f042 working together using g431 fdcan in backwards bacan compatible mode.
as far as the flags, you may have a good point i may not have paid attention and copied the can enable instead of the fdcan i am afk but will check in a few hours and if i fat fingered the enable switch that may well deserve me an ass kicking. stay tuned and thank you for pointing this out.