No Closed-Loop Spindle Control with Working Encoder

I'm using a 7i92 + 2x 5-axis Chinese BOBs and everything is wired up and working fine. 

The spindle is controlled using the BOB 0-10V analog output (converts the PWM signal to analog) and I'm using an analog-analog optoisolator to bypass my KBIC speed controller potentiometer.  The input of the optoisolator goes from 0-10V but the output only goes up to ~8.5V which is fine for me as it reaches near the maximum spindle RPM that I'm targeting.  I Just had to change the OUTPUT_SCALE to 15400 for 100% to equate to 9750 rpm.

I have a Masso optical encoder (quadtrature) connected to the BOB pins 11-13 and all the signals are working correctly when I manually turn the spindle. The RPM reading is very erratic until I changed the counter-mode to TRUE; not sure why but I can live with this since I don't really need the indexing.  I would like to fix it if possible.  I have changed the ENCODER_SCALE to -7 since the rpm was reversed.  It's reading correctly as compared to a tachometer I am using to verify.

I tried to perform a PID tuning process of increasing P until oscillation but all it does is increase the speed and I never hit any oscillation.  My pid.s.feedback always shows 0, not sure if this is normal.  Basically, I don't see any closed-loop control happening at all.  Any advise or suggestions would be greatly appreciated.

Thx, Mor

Any ideas? I’m stuck right now. Any help much appreciated. Thanks!

What PPR encoder?
What is the base period set at in the ini file?
Is the encoder wired to BOB?
Are you using a VFD or a servo drive for the spindle?

The signal spindle-vel-fb-rpm-abs is unconnected (so always 0)

This is a pncconf bug, it should create that signal from the output
of the absolute function, something like:


loadrt abs
addf abs.0 servo-thread
net spindle-vel-fb-rpm abs.0.in
net spindle-vel-fb-rpm-abs abs.0.out

tommylight wrote:

What PPR encoder?

7

What is the base period set at in the ini file?

setp    [HMOT](CARD0).pwmgen.pwm_frequency 250
setp    [HMOT](CARD0).pwmgen.pdm_frequency 6000000
setp    [HMOT](CARD0).watchdog.timeout_ns 10000000

Is the encoder wired to BOB?

Yes, 5-axis Chinese BOB (ST-v2)

Are you using a VFD or a servo drive for the spindle?

Neither; using 0-10V directly to potentiometer inputs.

 

PCW wrote:

The signal spindle-vel-fb-rpm-abs is unconnected (so always 0)This is a pncconf bug, it should create that signal from the outputof the absolute function, something like:loadrt absaddf abs.0 servo-threadnet spindle-vel-fb-rpm abs.0.innet spindle-vel-fb-rpm-abs abs.0.out 

That explains the open loop.  
I'm not that great with HAL editing nor how the PID and spindle pins/parameters are supposed to be set up.
Can you explain how I should implement the above code?
Attached is the HAL provided by PNCConf and I added the lines you provided.  I now get pid.s.feedback with some values.