Which products are affected?
Positioner Software Package V3.1
LenzeMotionControlV3.lib
What happens?
Immediately after the changeover to the following profile, the drive is decelerated with a set delay, exceeds the target minimally, reverses and reverses again after reaching the profile velocity. This swinging is repeated several times.
When does the problem occur?
In a time-scanned system, the exact point of time when the target is reached can possibly be between two calls of the controller. Theoretically, it is therefore possible that the drive exceeds the target minimally by using the setpoint from the last call. For theoretically extremely short distances of the following target at changeover, the drive may already have exceeded the target of the following profile with the last setpoint of the previous profile. As a result, the drive reverses and tries to re-approach the target with the final speed selected.
Very short distances of the following profile and high overchange velocities support the occurrence of the behaviour.
Possible diagnostics?
If the behaviour described before can be observed at the drive, the traverse path –defined by the following profile- should be extended considerably. As a result, the reversing behaviour does not occur anymore.
Short-term measures/recommendations?
None.
Evaluation
For the conditions described, the behaviour is reproducible. It can be detected during commissioning. In case of drives which only permit a positive direction of rotation, the reversing can cause damages to the machine / product.
The extremely unfavourable parameters which provoke the behaviour are not or very unlikely used in practical applications.
