Analog Feedback

In this mode, the torque or force sensor is connected to one of the analog inputs on the NI motion controller. That analog channel is used as the feedback sensor.

Tuning the control loop with a force sensor, which is an analog feedback sensor, produces the same results as with a position feedback sensor. Depending upon the resolution you are using, the system may require higher gains to ensure a faster response. NI motion controllers have 12-bit or 16-bit analog inputs, whose ranges can be set from 0 V to 5 V, –5 V to +5 V, 0 V to 10 V, and –10 V to +10 V. When you use counts for entering the values of position, velocity, acceleration, and deceleration, you do not need to enter the counts/revolution value for the axis.

Refer to the motion controller user manual for information about analog input ranges.

Torque Control Using Analog Feedback Algorithm

The following figure shows the basic algorithm for torque control using analog feedback applicable to both C/C++ and LabVIEW code.