Fanuc servo drivers with fiber optic

1. scrambled then encoded with 8b/10b
2. i couldn't find a way to generate this sequence with a single lfsr. instead i'm using eight 12-bit galois lfsrs with f(x) = x^9 + 1, each gives one bit of the byte sequence

dm17ry wrote: 1. scrambled then encoded with 8b/10b
2. i couldn't find a way to generate this sequence with a single lfsr. instead i'm using eight 12-bit galois lfsrs with f(x) = x^9 + 1, each gives one bit of the byte sequence

Thank you for answer.
1. I did group 10bit from NRZ data on QD75MH (using logic analyzer) but have some group is "0111111100'' (LSB - MSB) and it is not 8B10B encoding, it is SOF and EOF?
2. Look like it very difficult to conver to original data byte from scrambled data byte, can you take an example ?
3. Can share original data sample from controller and driver?

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!