JVL MIS17 Series User Manual page 100

5.3
Example 2:
The motor is not able to follow the ideal acceleration and therefore increases the velocity
to catch up the follow error. During the movement overloads also occur forcing the mo-
tor to go down in speed because lack of torque to overcome the load.
5.3.3 Current control (optional)
In a classic stepper motor system (not closed loop) the motor current is typically set to
maximum to make sure that the motor do not stall and loose track of its position.
The disadvantage is that the motor becomes hot and energy is wasted.
When running in closed loop, loss of position (motor stall) is not a concern and therefore
the control algorithms current control will (if enabled) adjust the current to a level where
the motor is able to follow the requested velocity and not loose the position.
The actual running current ("Actual torque" in MacTalk) is a percentage of the user de-
fined "Running current". The motor can never run with a higher RMS current than the
one specified in the "Running current" register, and the algorithm decreases the actual
running current according to the follow error.
100 JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS17x, 23x, 34x, 43x
Closed loop operation
Only MISxxx---H2/H4---