7i96 Spindle PWM

A relatively basic PWM spindle setup would be something like:

setp hm2_7i96.0.pwmgen.00.output-type 0 # 0=standard PWM/DIR mode)
setp hm2_7i96.0.pwmgen.00.scale (full_scale_rpm)
setp hm2_7i96.0.pwmgen.pwm_frequency (desired_PWM_frequency)

net spindle-on motion.spindle-on => hm2_7i96.0.pwmgen.00.enable
and
net spindle-speed-abs motion.spindle-speed-out-abs hm2_7i96.0.pwmgen.00.value
for unsigned output
or
net spindle-speed motion.spindle-speed-out hm2_7i96.0.pwmgen.00.value
for signed output (dir pin will follow sign)

The 7I96 has a single encoder input that can be used for spindle feedback if desired
if you mean for closed loop spindle speed control that's possible also

pncconf does a clever thing here in that closed and open loop spindle control are setup identically
(they always use a PID component) but the default spindle PID setup has only FF0=1 and all other pins
0 which means the PID provides no feedback and just passes the commanded velocity directly to the PID output (FF0=1 does this)
Simple using non 0 P or I terms changes the mode to closed loop

There's a scale issue, the encoder velocity is in RPS but the spindle commanded velocity is in RPM

I guess the options are to scale everything in RPS (using motions RPS speed pins)
or to scale the encoder feedback velocity to RPM using the scale component
The latter has the advantage of providing a actual RPM number for display