Need help setting up synchronized spindle

I connected the encoder and index
I got the spindle going and moving in the proper direction but only at full speed. I think the issue not getting the proper feedback to the PID.

I have my DYN4 Servo working as a spindle motor under PID control. Now I want to connect the encoder so I can do rigid taping. I have been searching and looking through the documentation. I found section "6.1. Spindle Synchronized Motion" section and followed it making the changes I thought made sense given that I am using a 7i76. I am using the encoder outputs on the DYN4 drive for the A&B phases and the optical detector on my spindle as the index.

I got the spindle going and moving in the proper direction but only at full speed. I believe that my issue is getting the correct feedback value to the PID.

Below are the spindle/encoder related HAL & INI file entries.

Thanks
John

# set the HAL encoder to 4551.111111 pulses per revolution.
setp encoder.0.position-scale [SPINDLE_9]ENCODER_SCALE
setp hm2_5i25.0.encoder.00.scale [SPINDLE_9]ENCODER_SCALE

# set the HAL encoder to quadrature simple counting using A & B.
setp encoder.0.counter-mode false

# connect the HAL encoder outputs to LinuxCNC.
net spindle-position encoder.0.position => motion.spindle-revs
#net spindle-velocity encoder.0.velocity => motion.spindle-speed-in
net spindle-index-enable encoder.0.index-enable <=> motion.spindle-index-enable

# connect the HAL encoder inputs to the real encoder.
net spindle-phase-a encoder.0.phase-A <= hm2_5i25.0.encoder.00.input-a
net spindle-phase-b encoder.0.phase-B <= hm2_5i25.0.encoder.00.input-b
net spindle-index encoder.0.phase-Z <= hm2_5i25.0.encoder.00.input-index

#// hm2_5i25.0.encoder.00
#// Parameters

#setp hm2_5i25.0.encoder.00.counter-mode true
#setp hm2_5i25.0.encoder.00.filter true
setp hm2_5i25.0.encoder.00.index-invert true
#setp hm2_5i25.0.encoder.00.index-mask false
#setp hm2_5i25.0.encoder.00.index-mask-invert false
#setp hm2_5i25.0.encoder.00.scale [SPINDLE_9]ENCODER_SCALE
#setp hm2_5i25.0.encoder.00.vel-timeout (Defalut 0.5)

setp hm2_5i25.0.encoder.sample-frequency 25000


#*******************
# SPINDLE S
#*******************
setp pid.s.Pgain [SPINDLE_9]P
setp pid.s.Igain [SPINDLE_9]I
setp pid.s.Dgain [SPINDLE_9]D
setp pid.s.bias [SPINDLE_9]BIAS
setp pid.s.FF0 [SPINDLE_9]FF0
setp pid.s.FF1 [SPINDLE_9]FF1
setp pid.s.FF2 [SPINDLE_9]FF2
setp pid.s.deadband [SPINDLE_9]DEADBAND
setp pid.s.maxoutput [SPINDLE_9]MAX_OUTPUT
setp pid.s.error-previous-target true

net spindle-index-enable <=> pid.s.index-enable
net spindle-enable => pid.s.enable
net spindle-vel-cmd-rpm-abs => pid.s.command
#net spindle-fb-rpm-abs => pid.s.feedback

net spindle-fb-rpm-abs => pid.s.feedback
net spindle-output <= pid.s.output

# ---Analog output signals/setup---

setp hm2_5i25.0.7i83.0.1.analogout5-scalemax [SPINDLE_9]OUTPUT_SCALE
setp hm2_5i25.0.7i83.0.1.analogout5-minlim [SPINDLE_9]OUTPUT_MIN_LIMIT
setp hm2_5i25.0.7i83.0.1.analogout5-maxlim [SPINDLE_9]OUTPUT_MAX_LIMIT
net spindle-output => hm2_5i25.0.7i83.0.1.analogout5

# ---setup spindle control signals---

net spindle-vel-cmd-rps <= motion.spindle-speed-out-rps
net spindle-vel-cmd-rps-abs <= motion.spindle-speed-out-rps-abs
net spindle-vel-cmd-rpm <= motion.spindle-speed-out
net spindle-vel-cmd-rpm-abs <= motion.spindle-speed-out-abs
net spindle-enable <= motion.spindle-on and2.ena.in0 estop-latch.1.reset
net spindle-cw <= motion.spindle-forward
net spindle-ccw <= motion.spindle-reverse
net spindle-brake <= motion.spindle-brake
#net spindle-revs => hm2_5i25.0.encoder.00.position motion.spindle-revs
#net spindle-revs => motion.spindle-revs
net spindle-at-speed => motion.spindle-at-speed
net spindle-vel-fb-rps => motion.spindle-speed-in
#net spindle-index-enable <=> motion.spindle-index-enable

net spindle-lockout-db estop-latch.1.ok-out => and2.ena.in1
net spindle-OK and2.ena.out => timedelay.0.in
net DYN-enable timedelay.0.out => hm2_5i25.0.7i76.0.0.output-03 hm2_5i25.0.7i83.0.1.analogena5
net spindle-Lockout hm2_5i25.0.7i76.0.0.input-07-not => estop-latch.1.fault-in

# ---Setup spindle at speed signals---

net spindle-vel-cmd-rpm-abs => near.0.in1
net spindle-fb-rpm-abs => near.0.in2
net spindle-at-speed motion.spindle-at-speed <= near.0.out
setp near.0.scale 1.02

# Use ACTUAL spindle velocity from spindle encoder
# spindle-velocity bounces around so we filter it with lowpass
# spindle-velocity is signed so we use absolute component to remove sign
# ACTUAL velocity is in RPS not RPM so we scale it.

setp scale.0.gain 60
setp lowpass.0.gain .8
setp lowpass.0.load false

net spindle-vel-fb-rps hm2_5i25.0.encoder.00.velocity => scale.0.in
net spindle-fb-rpm scale.0.out => abs.0.in
net spindle-fb-rpm-abs abs.0.out => lowpass.0.in
net spindle-fb-rpm-abs-filtered lowpass.0.out


INI File entries
[SPINDLE_9]
P = 2
I = 4
D = 0
FF0 = 1.03
FF1 = 0.00
FF2 = 0.00
BIAS = 0.0
DEADBAND = 0.0

MAX_OUTPUT = 5400.0
OUTPUT_MIN_LIMIT = -5400
OUTPUT_MAX_LIMIT = 5400
OUTPUT_SCALE = -10800
ENCODER_SCALE = 4551.111111
#((2048 * 4) / 1. = 4551.111111

"setp hm2_5i25.0.encoder.sample-frequency 25000"

Is fine for a one pulse per turn encoder = 600 usec filter but will fail at
more than about 10 RPM with ~4500 counts per turn

Thanks PCW.

I was eyeballing that one just before I shutdown for the night. That was to fix the display which is also not working right now but I wasn't going to address the display until I had it running correctly again.

John

It is possible that the encoder is counting reversed.

Take a look at the pid.s command and feedback signals with halscope.
If they have different signs, this is the problem.
There is also a possibility that one is in rpm and one is in rps...

I'm going to check everything over again when I get home but the RPM vs RPS comment brings up a question. Would it be better to use RPS or RPM in the PID? Or, does it not matter?

It's simpler to use RPS everywhere except if you want an rpm readout.

That was it. Commented that line out and the spindle and RPM display both work.

Thank You
John

Thanks for the help guys. I just rigid tapped my first hole. 6-32 in aluminum.

John