Fanuc servo drive integration

Diederik wrote: Just to recap: I confirmed each drive has 6 PWM channels, 3-CW, 3-CCW. I need to drive 5 Axis on this machine.

Can you elaborate on how that works? like, what do the pwm amplitudes need to do, in response to the commutation signals?

At the moment I am just confused. I can't even imagine how separate PWM signals for FWD and REV would work.

Hi Andy,

I Apologise. I had to translate from afrikaans, so I think I misunderstood my friend.
His answer was 3PWM+, 3PWM-
So also after looking at your attachment, I think it's supposed to be as follows:
phase-A
phase-B
phase-C
phase-A-inverted
phase-B-inverted
phase-C-inverted
Will this be my connections?
Sorry... I think I misunderstood the first time.

That makes _so_ much more sense.

Basically that is the direct-drive signals for each element in the 3-phase bridge:

en.wikipedia.org/wiki/Power_inverter#Three-phase_inverters

The Mesa 3-phase PWM can drive those, and the HAL "bldc" component can interpret the 4-line commutation signal to drive the Mesa 3-phase PWM.

So, all you really need to join-the-dots is a Mesa firmware with all 6 PWM outputs.

Thank you Andy.

Will my configuration as follows be sufficient?

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)

I don't think an ethernet card would be my first choice. I think I would look at a PCI 50-pin card like the 5i23.

There is a firmware definition that defines all 6:
github.com/LinuxCNC/hostmot2-firmware/bl...c/PIN_TPEN6_6_72.vhd
and github.com/LinuxCNC/hostmot2-firmware/bl...c/PIN_TPEN4_5_48.vhd
And it looks like it gets built for some cards:
github.com/LinuxCNC/hostmot2-firmware/blob/master/firmwares.txt
Note that this is the code that makes the linuxcnc-firmwares package, and it doesn't cover some of the newer cards, but does include some firmwares that Mesa don't distribute.

It looks like you could get a 5i23 and get a 6-channel firmware easily.
But the 5i23 isn't the cheapest card, and the 5i24 is just as capable.

Though, that is only part of the puzzle. What feedback do you get from the motors for commutation?

Thanks Andy.
I was under the impression that the Ethernet cards is the way forward? And I quite like it, because I can now have my computer in operators panel, away from switchgear enclosure.
If you recommend 5i23, won't the 7i80hd, and 7i90hd do the job just as well? If any specific reasons, I understand, but I don't have a pc with a pci slot at the moment. I'll have to source one. ..