Spindle Encoder selection Mesa

Hello

Looking to add a spindle encoder to my Bridgeport boss5 with a mesa 5I25/7I76/7I84 setup. The MPG on my control panel is hooked to the 7I84. The spindle encoder would be hooked to the 7I76 board. I thought at one point I had this questioned answered but no clue.

Max spindle RPM : 5000 RPM
Spindle control: Hitachi VFD
Would like to do rigid tapping and to know the true RPM of spindle

What is the max PPR the card could support?
Recommend PPR count?
Line driver (differential) or NPN open collector output?

Looking at automationdirect encoders with a coupler and a mount on top of the mill.

The PPR * speed limitation is almost always in the encoder itself, not the 7I76/5I25 which can count to more than 5 MHz

Because of this encoder limitation, high resolution encoders may not be capable of the required output frequency at high shaft speeds.

For example many of the KOYO encoders listed in your link have a maximum output frequency of 100 KHz

If you chose a 2500 line encoder, a 100 KHz limited encoder would only be guaranteed to work up to 40 RPS
and a 200 KHz model would still only be guaranteed to work up to 80 RPS (5000 RPM is 83.3 RPS)

A common 500 line encoder (2000 counts/turn) is probably a good choice ( a comfortable 41.66 KHz at 5000 RPM)

Differential (line driver) signaling is much better at noise rejection so I would always chose line driver outputs

Would you have a recommend encoder company that may work better or would this be more then enough to for rigid tapping?

Even 100 lines is fine for rigid tapping