Hi Rich
Now I am puzzled. Does the x40 uS only apply to the 'other inputs', and not to the index? That would be odd, because I am sure I solved a spindle speed problem by reducing the Index debounce down to about 1 or 0.
My logic was that the index pulse from a standard encoder is about 1/512 of a rev. At 3,000 rpm one rev takes 50 mS, so the index pulse is about 97 uS. Actually, it is half of that as the index pulse is usually only half the 4-cycle interval. An index debounce of 2 is 80 uS, and that can mask the 50 uS index pulse. Changing down to 0 meant that the displayed spindle speed at 3,000 rpm went from all over the place to a nice solid stable value.
Now, all this could be wrong of course, so please tell.
Cheers
Roger