Fanuc Drives

Dear everyone,

I have just successfully operated small Yaskawa drives with linuxcnc after a non-negligible amout of work lol. This was just a test run for the real thing because the real thing is we want to retrofit old machines with FANUC drives both DC and AC (Fanuc 6M and Fanuc OM). I made a try on a Fanuc 6 drive for one of the axes but could not get it to run with signals from Linuxcnc and I still don't understand why.

Is there something fundamentally different between those old fanuc 6 drives and the more modern yaskawa DR2 ones? I used step/dir signals and even tried the PWM outmput of the spindle but no result.

Anyone knows how to interface those Fanuc drives with linuxcnc via parallel port?

With the Yaskawa drives I used Parallel port and it worked just fine after some settings in the drives.

I would be grateful for any help. I'm still new to linuxcnc but passionate about it

In case anyone wants info about what I did with the small yaskawa drives, I'm happy to help.

Best regards,

Bouslama Karim from Tunisia.

I am pretty sure the old Fanuc 6 drives will require analog commands to run them. Just 1 for a torque command, or 2, a velocity command and a tacho singal (from a real tachogenerator on the motor, or a synthetic one like used by Fanuc.) The 0-M drives, I'm not sure about, but they might be similar, or could be much more difficult to figure out. The problem with Fanuc drives in general is they were never designed or intended to be used with other hardware. (and I think Fanuc tried their hardest to keep it that way)

One thing is for certain, they will never work with simple step/dir commands like your Yaskawa drives.

Thank you friends for your help.
well we also have some machines with Fanuc OM controllers and they have digital drives which I think might be a bit easier to adapt.
Maybe the Om drives even accept STEP/DIR signals? This would be great.

Modern Yaskawa drives actually worked quite well with STEP/Dir pulses (Yaskawa DR2 from the scrapyard hh).

Anyone knows if at least the more modern OM drives can be made to run with parallel port from Linuxcnc?

Best regards,

Bouslama Karim

Fanuc has at least 3 basic types of drives

a06b-60XX with XX up to 57 are mostly analog +-10V velocity mode drives and can run with any of linuxcnc's
Analog servo interface systems (Mesa, Pico systems etc)

a06b-60XX with XX from 58 and higher are "digital drives" and take 3 phase PWM (some models take differential PWM others are single ended) and return 2 phase currents back to the controller as analog voltages. In this case the controller
implements the Field oriented control

Later drives use a high speed proprietary serial bus (FSSB) to communicate from the controller to the drive

None of these drives can be driven well by a parallel port