Another Fanuc retrofit thread

Hi,
Like many before me I have a VMC with Fanuc running gear that I would like to retrofit to run with LinuxCNC.
It is of 2000 vintage with an Alpha series servo drive (A06B-6102-H211) running 3 Axis and used to have an 18MC control. The servo motors have the Fanuc pulse-coder encoders.
I accept that the likely path is to replace the drive and implement some Mesa and/or Pico hardware, however to start there is a very informative thread here that stretches from 2012 to 2017 discussing the possibility of interfacing directly with the existing Fanuc drive. They employ a 3-phase PWM system with additional data lines and an, at the time, unknown communication protocol. At the time it seems there was no resolution, but I was wondering if in the intervening years someone had cracked the problem?
I am at the start of this journey and will likely have many questions, but starting here as priority one is determining what hardware I need to purchase.
Thanks in advance

Thank you for the reply.
I see that I made a mistake in my original post, the part number I listed is that of the serial spindle amplifier. I have not decoded the serial communication protocol for this as the machine is not in an operational state, but the spindle motor can be driven from a VFD so that is likely my best option there.
The servo drive is Fanuc A06B-6080-H304, which is a 3-axis drive the uses the 3-phase PWM system with addition data lines spoken about in the thread I linked to.
My current thinking is to replace the servo drive with 3 x Mesa 8I20 3-phase amplifiers, 3 x Pico Systems converters for the Fanuc encoders on the servos (or does Mesa support the Fanuc pulsecoder signals?) and replace the spindle amplifier with a VFD.
Where I'm stuck at right now is determining the correct Mesa hardware to control the servo amps, the VFD, the encoder inputs, a pendant if possible, and some IO for limit switches and a few other items. I am hoping for an ethernet solution to the computer.
I was thinking perhaps starting with a 7I80DB Anything I/O card with a 7I74 for serial IO to the servo drives, plus further daughter boards for the other items, but I just haven't had the time to go through the options yet. Any suggestions for suitable Mesa hardware would be greatly appreciated, otherwise I'll come up with a topography and post here for critique.

andypugh wrote:

I don't know if anyone has cracked the Fanuc optical / serial protocol.

 

I don't believe. we're having some trouble with those yellow boxes right now. Even the fanuc technician does not have a diagnostic tool. This is a very well-kept secret even at fanuc.