wj200 vfd - spindle-speed-out to frequency #?

Hi, all;

I've been working with my mill rather than on it for a while, running a copy of pre-2.7.0 that I pulled from the git repository a while back. I've reached a point in life where I have a little spare time now and I'd like to establish full spindle speed control with my VFD. Previously I've just been using full speed (I've mostly been cutting aluminum) and the variable speed head.

I've found a couple of issues that I hope will be solved in 2.7.0, so I'm going to take the time to install a clean hard drive and the new ISO image.

Looking at the docs though, one thing isn't any clearer to me from the old version to the new - how do I attach the pins on the wj200 HAL object to the motion object in such a way that spindle-speed-out is converted to an appropriate 0-X hz number to feed to wj200-vfd.0.commanded-frequency?

I did see a reference to a conversion like this in the general docs for VFD modbus setup, but nothing on how to do it. It should be a straightforward bit of math, based on the pole count of the motor in use and the frequency... I know it's possible to read the pole count from the VFD but I don't know if the driver is set up to do it.

Anyone done this or something like it, and have a recipe for it?

Thanks,
Erik

See man motion9
use

Hmm...

motion.spindle-speed-out-rps OUT float
Desired spindle speed in rotations per second


Okay... maybe I'm too tired to think here, but I can't see how this does much? Is there a spindle-speed-out-hz?

Hz is cycles per second, and when referring to revolution speed aka revolutions per second.

Okay, so then my spindle motor runs at 1725rpm at 60 hz.

To get eg. 1725 rpm on the spindle I'd assume spindle-speed-out-rps is set by HAL to 1725/60 or 28.75. To turn that into the hz command I need for the motor I'd have to multiply it by 2.087 and set wj200-vfd.0.commanded-frequency to the product?

Still not sure how to do this...

Then you could use
linuxcnc.org/docs/html/man/man9/mult2.9.html
setp one of the mult2 inputs as the constant you need to multiply by and the other one to spindle-speed-out. Then connect the output of mult2 to your vfd's input.pin.

Okay, that makes sense. I can basically calculate a constant, then verify the speed of the spindle with a handheld tach and adjust the constant as needed.

I've got the new Debian based install on the control PC now, so I should be able to get this set up tonight.

Thanks!

Erik