Can I use Mesa 5I20 + 7I47S + 7I42TA for AC Servo?

Hello I had purchased the Mesa 5I20 + 7I47S + 7I42TA for a different project using DC Servo's and I recently purchased AC servo's and am wondering if I can drive them with my current cards. The drives I have are 1x SDB50NK5 for using a 3.8KW servo as a spindle drive and 3x SDB20NK3 drives for driving three 1.8KW servo's for motion control. The drive can do step/dir and Speed/Torque control modes. In the speed control mode only the Z phase part of the encoder is showing as being able to be output. Here is the manual for my series of drives. If I use step/dir I can still output the A/B/C/Z encoders to LinuxCNC but would having the drive also using it's PID loop throw a wrench into the mix?

What would be my best approach at connecting these drives and using LinuxCNC with it? If I need new daughter cards which one should I get? I know the 7I77 is for velocity mode servo control. All help is appreciated.

Thank you,
Jeremiah

You should be able to do step/dir control including encoder feedback
(either for monitoring or PID control) with what you have.

It seems strange that you cannot get encoder feedback in the velocity or torque modes,
as those modes _need_ encoder feedback for position control

If you can figure out how to get encoder outputs in velocity or torque modes
a 7I33TA will give you 4 analog channels and encoder inputs (replacing the 7I47S)

Andy I was thinking the same thing. Thank you for looking at it. I'm going to try it out this weekend to see if I get feedback out of the drive in speed mode. If I do I'll pick up a 7I33 card to hook up the servo's with.