Fanuc servo drivers with fiber optic

1. yeah, as far as i remember. they are exactly what i called "slightly modified"
2,3. that was quite some time ago, i need to search my archives... but actually, it is not hard after you know what's going on. the QD75MH sends some empty frames (entirely zeros except the crc at the end) - that's your pseudo-random byte sequence in plain text. just xor it with other command/response frames. those also have a lot of zeros inside, so you'll know when it is correct.
if you will still have hard time figuring it out - email me, i'll try to find my old notes...

Do you still have some note regarding the fssb protocol? I'am looking for any bits of information. Thanks!