Fanuc servo drive integration

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03 Nov 2015 02:17 #64638 by andypugh
Welcome to the forum.

Are you adding information to this thread (Which is rather old) for future reference? In that case, thank you.

Or, do you have some questions?

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03 Nov 2015 10:11 #64656 by jmelson
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. Also, the top and bottom transistor of each pair must never be on at the same time, or it will likely blow the transistors. It might be better to just use 3 PWM generators with a pair of deadtime generators each to produce the 6 transistor drive signals. This would get into custom FPGA development.

Jon

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03 Nov 2015 11:12 #64659 by MANOLOMARAVILLAS
Control blcd jon .picosystem.

Pwm bldc 8015a chino

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03 Nov 2015 18:12 #64676 by andypugh

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

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22 Nov 2015 23:54 - 22 Nov 2015 23:54 #65677 by jCandlish
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?

.
Last edit: 22 Nov 2015 23:54 by jCandlish.

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23 Nov 2015 02:12 #65681 by jmelson

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

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23 Nov 2015 05:54 #65686 by jCandlish
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

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23 Nov 2015 16:44 #65705 by PCW
Replied by PCW on topic Fanuc servo drive integration
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
The following user(s) said Thank You: Diederik

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23 Nov 2015 19:22 - 23 Nov 2015 19:44 #65713 by jCandlish
You have just described my thinking.

I envision a fairly large 'sheild' card for a SOM card that has sufficient GPIOs to cover the functionality of a FANUC 18, with the same form factor as the FANUC board and the same Honda connectors and etc.

I don't think anyone has looked at the FANUC spindle drive yet? It has a different interface than the kinematic servos. Also the FANUC I/O module protocol would need to be reverse engineered.

Quite a piece of work, but that is the (pipe) dream. MANOLOMARAVILLAS comment to this thread gave me hope that others might document concrete progress on the FANUC front.

I would need to get more spares to be able to contribute at this time. The FANUC machine I have is running good, but it is limited by its motion controller to 3 axis and is quite weak at HSM. (not deep enough look-ahead)

MANOLOMARAVILLAS please come back and tell us what you are doing.
Last edit: 23 Nov 2015 19:44 by jCandlish.

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05 Feb 2017 00:37 #87320 by Diederik
Has any development gone into this?

I would love to know which mesa cards to use for pwm. Andy, you mentioned about a fpga card to use. What would you suggest? Will something like a 7i80DB work? together with a 7i75? I suppose I will need 30 I/O for a 5 axis machine with pwm. so my configuration for this machine can be as follows:
7i80DB => J2 => 7i75 => PWM
=> J3 => 7i75 => PWM
=> J4 => 7i77 => 7i84(SS)
=> J5 => 7i77 => 7i84(SS)

Would this hardware configuration work for the PWM red cap Fanuc servo drives?
Just to recap: I confirmed each drive has 6 PWM channels, 3-CW, 3-CCW. I need to drive 5 Axis on this machine.

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