Mesa 7I76 with Spindle encoder and MPG-need help

I am retrofitting a Bridgeport Boss5 machine and have purchased a Mesa 5i25 and 7i76 daughter card for it. I see how to configure the spindle encoder but an unsure of how to add the MPG encoder to the config and what IO pins to connect it to. I was planning to run the field power for the limit switches at 24 volts, this will work for the mpg axis and step size selection switches but what about a 5 volt ttl encoder?

The 7I76 MPG inputs will work with 5V signals (they have a 2.5V threshold)

If you have a single MPG, its A and B lines would connect to field inputs 16 and 17

So if I understand this right, the logic high level is 2.5 volts even when using field io powered at 8-32 volts?

slowly slogging my way through a retrofit on my Boss, after sorting a motor issue I am back to wiring things up. Is the 5 volt ground connected to the field io ground? Can it be? The pendant I use is wired up to a db 25 connector and the switch commons and encoder 0volt are shared.

Field I/O ground is isolated from 5V ground.
They can be commoned if desired

I plan to use mode 2 for the 7i76 and set the mpg encoder up on 16 and 17, the encoder is a 5 volt encoder. How do I set this up in Linux cnc? The rest of the io on the pendant can be run at the field io voltage of 24 volts I just need to seperate it, can I keep it isolated from the 5 volt ground in mode two?

I picked up a buck converter and have the MPG encoder wired to TB5 16 and 17. The rest of the pendant IO is also wired to TB5 as follows axis select x 18, y 19, z 20, A 21, 1x step 22, 10x 23, 100x 24, and estop to 25. The io other than the encoder are set to use the field power at 24 volts. I looked through the config tabs in pncconf and it was not apparent to me how to configure anything other than the estop. Can someone point me to a guide or post on how to set this up with the 7i76? Thanks

I have made a little more progress, I found were to set the serial to mode 2 and I now have the encoder options for for pins 16,17,18 and 19. I am not seeing how to set the axis select or the step size though.