mesa 7I29 compatible anything i/o cards

Thank you for all the help provided in my last topic.

Mesa cards seem very good value. If I use 2 x Mesa 7I29 dual H Bridge cards to drive the SEM 3nm dc servo motors, what is the best combination of cards to connect to the computer ( using Linux ) ?

On my mill, the x and y axis use glass scales for position and the z uses a rotary encoder on the motor.

Where does the tacho feedback go back in to the card?

Thank you again for any help and advice. If I get this right, the next project is a Harrison M300 needing a control and crosslide or turret, but lots to learn first.

a 5I20 is a good choice here.

Do you know the current rating of your motors and the motor power supply voltage?
the 7I29 is rated 22.5A peak per Hbridge and 180V max

The 7I29 is a simple HBridge and has no tachometer inputs,
however the function of the tachometer can be replaced by the encoders
since the encoder counter hardware under LinuxCNC has good velocity estimation.
This will likely only work well if you have rotary encoders or very near
0 backlash on your scales however.

Forgot to ask: Do your linear scales have quadrature out?
If they are old enough they may be sine/cosine out and need an interpolator

I think it is time for PLAN B.

I was hoping to use new drives but it is looking much easier to get the old drive card repaired.

I believe this should allow me to use mesa 5I25 and 7I77 cards ( the same control as the Bridgeport series 1 project by dembedded)

Hopefully I can follow this previous project to help work through mine.

I mentioned the velocity estimation because you can do OK with the 7I29s
without any tachometer feedback since LinuxCNC Encoder velocity estimation is a good velocity signal for the PID loops D term which replaces the external velocity loop. However, if you can fix the existing drive, that would simplify things.