Mesa 7i96 pwm to drive servo

I have a 1.8Kw servo that I would like to try and get working with a Mesa 7i96

The drive will accept :-
step/dir for position control I have it working in this mode but it is not suitable at low rpm ie 500. this is on a mill.
Here is a bad vid of the problem ie not hold speed. the rpm on the drive display is the same and the gui.


-10v+10v for Speed, torque. Is there a way to achieve this with the 7i96.

I have used pwm to 0-10v converters before but this won't work with -10+10V

Thinking aloud could it be done with two of the above converters back to back somehow feeding the pwm into both converters !!! I am aware that I could use a Mesa 7i77 but that would be overkill !

If the drive does not control the RPM well in position mode, I'm not sure if it would be any better in velocity mode. Have you tried tuning the drives PID loops?