L_MC1P: Switching between operating modes: Tracking error is not correctly taken into account, this can have an effect when closing the brake, among other things (corrected from V03.24.01)
Corrected from:
Library: L_MC1P_MotionControlBasic (FAST Motion) from V03.24.01
(Update über Package-Manager)
Response of the new version:
When switching from speed to position control, the set position is now always equated with the actual position.
By resetting the pending drag error, no more erroneous balancing movement occurs now.
What happens?
Under the conditions mentioned below, there is no comparison of the target position with the actual position, which initiates a compensation movement to an incorrect target position.
When the brake is closed (automatic brake activated), this leads to a torque build-up against the closed brake.
When does the behaviour occur?
Control mode of the motion axis under Sub 090 = [10] (speed control) and
Motor encoder is source for the actual position value (Sub 092 = '-') and
during the movement of the axis, a position difference has built up between the set position and the actual position, because e.g. the drive cannot follow the torque limitation due to the engagement and
in the subsequent standstill, either a QSP application is triggered or the inverter is locked with activated automatic braking.
The described behaviour does not occur if the position feedback is done via an external encoder.
The following short-term measures are possible to prevent the occurrence:
During the transition to the axis state Standstill, implement the deletion of the tracking error that has built up by means of FB 'L_MC1P_ResetFollowingError'.
For the cases described (controller disable, QSP application), trigger a quick stop in the inverter in parallel via FB 'L_MC1P_SetQuickStop'.
Activate the drag error monitoring and check the set threshold to detect and prevent any compensating movement that may occur.
