Fanuc servo drive integration

Control blcd jon .picosystem.

Pwm bldc 8015a chino

jmelson wrote: These Fanuc servo amplifiers require SIX PWM signals for each axis. If you have 5 motors on the robot (typical) then you would need THIRTY fast PWM channels to drive the 5 axes

There is a Hostmot2 firmware with 6 channels of 6-pin PWM and 6 channels of encoders:
git.linuxcnc.org/gitweb?p=hostmot2-firmw...3e244e0b93d7de8c5667

There is another for 48-pin cards with 5 channels of PWM, but that has no room for anything else at all.
git.linuxcnc.org/gitweb?p=hostmot2-firmw...45055d75e18ae99ec106

This is interesting.

Did anything ever come of the previous effort to interface FANUC AC servo drives? What about FANUC AC spindle drives?

Quite a timely subject given the quality of the AC drives+servos and the obsolescence of the late 90s' early 00s' controllers.

Has anyone actually retrofitted just the controller on a red-cap based machine, and documented what was done?

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_jC wrote: This is interesting.

Did anything ever come of the previous effort to interface FANUC AC servo drives? What about FANUC AC spindle drives?

Quite a timely subject given the quality of the AC drives+servos and the obsolescence of the late 90s' early 00s' controllers.

Has anyone actually retrofitted just the controller on a red-cap based machine, and documented what was done?

.

I have converters for both the first-generation Fanuc encoders and the later serial pulse coders. These give you standard quadrature plus index encoder output plus commutation signals. These could be used with a variety of well-known brand servo amplifiers such as Servo Dynamics, AMC and Copley.

I also have servo amps and controller for LinuxCNC that can be used with Fanuc motors. They go up to 150 V and 20 A peak. So, they are quite good for smaller Fanuc motors, but not really beefy enough for the largest motors.

Jon

I was hoping for a solution that replaces only the controller, and keeps as much of the magnetics cabinet intact as possible, including the existing cabling, powersupply and servo inverters.

The Controller <=> Servo inverter signaling seems quite similar to the Inverter <=> Drive signaling.

I take it from your reply that the current approach is to replace the FANUC Servo Inverters then?

https://lh3.googleusercontent.com/dIx1W-qv9hbpYImoEkqb5KXTtDGcZ4B9At5SoAGrmFo=w800-h600

Its possible with Mesa hardware but requires a few missing bits (Mesa already supports reading the Fanuc serial encoders without losing the absolute position information and has 3 phase PWM output capability)

If I had enough time (I dont) I would make a Fanuc Servo amp daughtercard, This would have a multichannel A-D for the
analog R/S current feedback signals, sets of buffers for the PWM signals (some models are differential, some single ended)
These buffers must be floated to read the drive state in fault conditions (some of the PWM signals are bidirectional so
the drive inputs PWM when running but outputs fault status when in faulted state). Ideally the daughtercard would have the proper Honda (older drives) or high density (newer drives) connectors for compatibility with existing cables