SIM_SPINDLE comp usable for lathe threading?

I have a lathe with all servo motors, including the spindle. I'm using 7i92 => 7i77 and everything is working fine but since the encoders are attached to the servo motor I'm still missing the index pulse per revolution (of the chuck) needed for G76 threading.

I was looking at the best way to add an encoder/sensor for the index but stumble on this SIM_SPINDLE component that appear to do exactly this given that it is a 'Simulated spindle with index pulse'. I'm then wondering if this could work 'good enough' for normal (slow speed) threading... and how.

Also, where is the index pulse??? I see index-enable pin that reset position-fb pin but what is the point of this since there should be 1 index pulse per revolution??? The rev count will then never exceed 1 under 'normal' circumstance...
 

...Further reading seems to indicate that this is for simulation only...

Hey thanks Andy!

I've seen this and was thinking about it. One of the problem is that I have no 'pulses'. I have a 7i92 => 7i77 all analog setup. Including the servo spindle. I guess I could use the encoder A or B return from my drive (AB ultra3000) and feed that as pulses for your component...

But then the problem I have is that the result of the encoder ppr should then be translated to the final ppr of chuck rotation. The final number should be a whole number since any fraction will make the reference to slowly drift... To make thing worse the slow speed on my gearbox is 12:29  or 0.41379310344  at 4000 ppr (motor side) I would get 9666.667 pulse per chuck revolution.

I don't think I can use this because for every chuck rotation I will either be 1/3 of a pulse ahead or 2/3 pulse behind. For threading operation the entry point would drift away too fast I think.

I'm thinking that:
- I could modify the gearbox to have a workable ratio.
- Use an encoder with gazillion bits of resolution to minimize the drifting error.
- Or simply going back to the original idea of using a sensor on the spindle.

(Yeah, feeling old and lazy, so #3 is the preferred option for today)