[SOLVED] Bug: PnCConf does not set up servo spindle PID feedback correctly.

Hello,

After rewriting my HAL file and adding spindle-at-speed detection, I found out my spindle was not running at the correct RPM. After some investigation I found out this is because the HAL file generated by PnCConf does not correctly connect any feedback to the spindle PID loop.

Only spindle-fb-rps is connected directly to the signal from the 5i25 encoder signal, however the spindle feedback is connected to the RPM signal instead of RPS (spindle-feedback-rpm). This signal however is not connected anywhere else, meaning there is no RPM feedback going to the PID loop.

I have included an older HAL file that should be almost the exact same as the one generated by PnCConf, only some small alterations and none to the relevant sections. I have since resolved it in my HAL file by simply using the scale component, however this should probably be fixed within PnCConf as well.

It would probably be cleaner to use RPM everywhere and avoid the scale component
(since the driver in 2.8 exports the encoder velocity in RPM as well as RPS)

net spindle-vel-fb-rpm <= hm2_5i25.0.encoder.05.velocity-rpm

does resolvers also have the velocity-rpm pin?

Yes

Thanks - pushed the fix to 2.8/master

Hello,

i think i have the same problem, too.

I added the fix in PNCConf today, but i have no spindle regulation anyway.

PNCConf added this line in my HAL file: net spindle-vel-fb-rpm <= hm2_7i76e.0.encoder.00.velocity-rpm

I tested different PID parameters all day.

I`m using a Mesa 7i76e with 7i84s and a Lenze Vector 8200 VFD 0-5V, Speed range 1000-2500rpm.

My HAL and INI is in the attachments.



Hope you can help me
Steffen

Note that the encoder velocity signal "spindle-vel-fb-rpm" is not connected to anything

I would change this:


to this:


and remove the scale component since it is not used:

Hi PCW,

thank you, i just tested it but still the same problem.

Can you post the current hal/ini files?

Did you look at the pid.s.command and pid.s.feedback pins?
These values are key to diagnosing any closed loop speed control issue

here are the new files.

i have no counts at the pid.s.feedback pin