Fanuc servo drivers with fiber optic

Hallo friends,
I would like to connect Fanuc servodrivers with FSSB interface (optical) to Mesa and LinuxCNC. I am afraid it is not easy First I checked if analog interface is still present in these drivers, but probably not. I still thinking to try to hack this optical link, but first I would like to ask if somebody has tried this before and would like to help me or cooperate. Or tell me it is mission impossible
Thanx for answer.

Do you have a working optical controller and a way to log the transactions?

did that for mitsubishi sscnet iii which uses similar optical interface. it required some effort to get the data. packets are XOR'd with a pseudo-random sequence and then transmitted using a slightly modified 8b/10b encoding. took some time to understand how they generate that sequence to implement the RNG in hardware.

if fanuc didn't bother with some kind of real encryption then it is probably possible to hack given some dedication and yes, you'll definitely need a working controller to log the link...

i have an FPGA PCI card with 125Mbit POF transceiver which should be compatible with fanuc's

yurtaev.com/yssc3p.html

andypugh wrote: Do you have a working optical controller and a way to log the transactions?

Yes, I have. It is in a new, cca. 1 month old machine - my friend's mistake We have a machine with LinuxCNC, but he needed next one and ordered machine with Fanuc. Now he see how stupid Fanuc controller is (compared to LinuxCNC) and he wants to rebuild it. I do not want to change servos, it is a lot of work and money, I preffer to change controller only. Problem is with optic interface.
I have no idea about data protocol and speed used (should be 50Mbit?!?), so my first idea was to connect oscilloscope to optical transceiver in controller and want to see at least something, measure the speed etc. and then decide next step. Unfortunatelly, I didn't found any testpoints and connect to optical transceiver terminals is a bit tricky, it means to diassemble the controller too much. Well, if there is no other way, I will do this. But first I am looking for way to connect some interface to optical bus and start there.

I have no idea how to do this, but Google seems to suggest it is possible,
www.joshruppe.com/fiber-optic-tapping-tapping-setup/
for example.

dm17ry wrote: did that for mitsubishi sscnet iii which uses similar optical interface. it required some effort to get the data. packets are XOR'd with a pseudo-random sequence and then transmitted using a slightly modified 8b/10b encoding. took some time to understand how they generate that sequence to implement the RNG in hardware.

Thanx a lot for answer! Very good information that there is a way to solve it.

if fanuc didn't bother with some kind of real encryption then it is probably possible to hack given some dedication and yes, you'll definitely need a working controller to log the link...

No problem, I have full working system to log communication and many experiences with reverse enginnering, but I am not sure it will be enough

i have an FPGA PCI card with 125Mbit POF transceiver which should be compatible with fanuc's
yurtaev.com/yssc3p.html

Very nice! I thought FPGA is right way. Is it possible to get such card?