Schematic

Modes Description
Advanced Digital Motor Controller User Manual 121
SECTION 10
Closed Loop Speed and
Speed-Position Modes
This section discusses the controller’s Closed Loop Speed modes.
Modes Description
Close loop speed modes ensure that the motor(s) will run at a precise desired speed. If
the speed changes because of changes in load, the controller automatically compensates
the power output so that the motor maintains a constant speed. Two closed loop speed
modes are available:
Closed Loop Speed Mode
This mode is the traditional closed loop technique where speed is measured with a speed
sensor. The speed is compared to the desired speed and a PID control loop adjusts the
power output up or down in order to reach and maintain that speed.
Speed Command
PWM
Motor
Speed Sensor
Speed Feedback
-
PID
Closed Loop Speed Position Control
In this mode, the controller computes the position at which the motor must be at every
1ms. Then a PID compares that expected position with the current position and applies
the necessary power level in order for the motor to reach that position. This mode is espe-
cially effective for accurate control at very slow speeds.