I want to control an old DC servo amplifier with a CNC controller. The servo amplifier takes +-10V command signal to control the speed (0V = stop, -10V full CCW, +10V full CW). The CNC controller can generate either: 1) PWM + direction 2) PWM (for the high side) + inverted PWM (for the low side), 3) PDM + direction.
Generating analog voltage in one direction is simple - I take the PWM signal, put it through an RC low pass filter and then amplify it through an op-amp. However, I am struggling to find a solution which would allow me to invert the command signal based on the direction signal. What would be the simplest solution? Or is it achievable with the low- and high-side signal?