7i76E one PWM needed

Chose the other differential pair output (so its 0V when the 7I76E is idle) and invert the PWM output in HAL

Must have been too late :silly: Don't know why I forgot it's differential.. Thanks!!!

Okay this works, but there is some sort of glitch of a few 100ms during startup of Linuxcnc. The negative pin is low when linuxcnc is not running which is good. At startup of linuxcnc the pin will go high and stay high until the invert command is executed.

So I'm not sure it can be solved in linuxcnc. Is it possible to change the FPGA code so when I use the positive pin PWM will stay 0 if Linuxcnc is closed?

Yes, you would probably have to change the FPGA code to get a glitch free startup
You will always need to use the negative output as this is the only output that will stay at 0 when linuxcnc is not running

What is required is to make the FPGA PWM output active low. To do this as a hack you would
change ( in pwmpdmgenh.vhd )

to

I've got this part working, but I'm facing another strange problem which is maybe related to the bit file.
I've hooked up a spindle encoder. I don't know why but the index signal does not work. I have the encoder in counter mode because I only have one input on signal A. And I've hooked the index signal. When I open hal scope I can see both signals are working. The index signal is available at hm2_7i76e.0.encoder.00.input-index.

Hal looks like:
# ---Encoder feedback signals/setup---

setp hm2_7i76e.0.encoder.00.counter-mode 1
setp hm2_7i76e.0.encoder.00.filter 1
setp hm2_7i76e.0.encoder.00.index-invert 0
setp hm2_7i76e.0.encoder.00.index-mask 0
setp hm2_7i76e.0.encoder.00.index-mask-invert 0
setp hm2_7i76e.0.encoder.00.scale [SPINDLE_9]ENCODER_SCALE

net spindle-revs <= hm2_7i76e.0.encoder.00.position
net spindle-vel-fb-rps <= hm2_7i76e.0.encoder.00.velocity
net spindle-index-enable <=> hm2_7i76e.0.encoder.00.index-enable

# ---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
net spindle-cw <= motion.spindle-forward
net spindle-ccw <= motion.spindle-reverse
net spindle-brake <= motion.spindle-brake
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

What could be wrong? The spindle-index-enable signal alwaysstays FALSE.

Regards Chris

If motion.spindle-index-enable is false (so hm2_7i76e.0.encoder.00.index-enable remains false),
The index hardware is disabled so the index input does nothing

For spindle synchronized motion, spindle at speed must be true for motion to set index enable,
so I would check this first