Encoder Spindle Index not working

I am struggling trying to setup spindle encoder on a converted manual lathe. I am using a 5i25+7i76 combo.
I need to know the rpm and have a starting point to make threads (G76 syncro motion) . The A and B channel seems to be working fine, setting low pass filter gain small, aprox 0.03, with these value RPM remains stable. Wired Z and Z/ channel to IDX+ and IDX- pins of the 7i76 but turning lathe chuck by hand spindle index signal never change from false to true in a complete turn in hal meter. The encoder P/N is SICK DBS50E-S5AK01000. I am stuck and will appreciate any help.

Thank you.

José

I would not expect to see the index signal with halshow (its typically
too short to see unless you turn the spindle _very_ slowly)

The way to check index operation is to:

sets [index_enable_signal] true

Then monitor [index_enable_signal] with halshow as you slowly
rotate the spindle. If index is working, [index_enable_signal]
should go false at the index location.

[index_enable_signal] may have different names depending on how
the hal file was created