Raspberry Pi 4 & MESA 7i92

hm2/hm2_7c81.0: IO Pin 014 (P1-21): Encoder #0, pin A (Input)

hm2/hm2_7c81.0: IO Pin 021 (P2-03): StepGen #4, pin Step (Output)

Encoder 0 'A' is on GPIO14 and P1 physical pin 21
(if unconnected it should read high since its an input with a pullup)

Stepgen 4 step pin is on GPIO21 and and P2 physical pin 3
(if idle, that is not during a step pulse, it should read low)

I agree with you all.

My problem is when I tied my RPM pulse generator to P1-21 it never drives low, it remains high all the time (checked with a scope).
I'll check it again.

Thanks!