Auto Correction - JVL MIS17 Series User Manual

5.2
5.2.1 Position "Auto correction"
This feature is only active when the motor is in Position Mode. Also the function is only
active if the motor is equipped with one of the encoder options -H2/H3 or H4.
The function can be called a semi-closed loop feature since it do only correct the motor
position after a move have been done or tried done and not dynamically during a move
like closed loop will do. See also
The auto correction feature can be useful to assure that the motor reach its target posi-
tion. The feature will take effect if for example the movement was physically blocked,
the torque of the motor was insufficient, or a bad value for start velocity or acceleration
were used. It might also be used to handle occasional mechanical oscillations.
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5.2.2 "Auto correction" - basic function
The auto-correction feature is only used when the motor has stalled and not reached its
final target position within the given position window.
Each time the motor has done a movement the "Actual position" counter and the "En-
coder position" counter is compared.
If the difference without sign is within the value specified in the "In position window" as
shown below no further action is taken.
If the difference is larger than the value in the "In position window" the motor will try to
correct the position by doing a new motor movement. The "Max number of retries" is
the number of times the motor will try to correct the position, and the "Settling time be-
tween retries" is the time the motor will wait between each retry.
The AutoCorrection system will first wait (unconditionally) for a certain time (settling
time) to allow the initial movement to settle mechanically before testing for the target
position. It will then attempt a normal movement, using the same values for velocities and
acceleration as the movement that failed. It will continue until the encoder position is
within the target window, or the selected number of retries has expired.
Note that AutoCorrection will only start after the value of the Position (P_SOLL) register
is changed. In other words, changing P_SOLL (not just writing the same value again) will
reload the maximum number of retries and set the Auto Correction Active status bit.
The Auto Correction Active status bit will remain set until either the position is within
the target window or the max number of retries has been exhausted.
Also note that if the motor is used to control other motors by sending out the pulse and
direction signals on digital outputs, any extra movements caused by AutoCorrection will
send out additional steps to the other motors.
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94 JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS17x, 23x, 34x, 43x

Auto Correction

The Auto correction feature is not recommended to use if the motor also has
enabled the closed loop regulation.
The Auto correction feature is not recommended to use if the motor also has
enabled the closed loop regulation.
Introduction to closed loop
Only MISxxx---H2/H3/H4---
operation., page 98