Spindle encoder configuration (with G76 threading command and Mesa 7i96s)

I have a 600PPR quadrature encoder linked to my spindle with a 3:1 ratio, so 7200 PPR @ mesa spindle encoder input. A & B quadrature signals only, no 1PPR signal, but I don't think I need the 1PPR signal.

In Halshow
 - spindle.0.revs counts up as expected
 - spindle.0.speed-in appears correct
 - spindle.0.index-enable is disabled

in my SM-10.hal file I have: 
net spindle-index-enable      <=>  spindle.0.index-enable

IF I comment out this line, I can then enable spindle.0.index-enable manually in Halshow

Regardless when I try to open my 2 line G76 program I get the following error:
"Chosen spindle(0) not turning in G76"

I'm not sure if this is a HAL configuration issue or perhaps I need to do something in the gcode prior to the G76 command, not sure?

I have attached files for clarity.

Thanks,
Jeff


 

For threading, you need a 1PPR signal (index) from the spindle.