Which products are affected?
L_MCProfileGenerator profile generator of the LenzeMotionControlVx.lib function library as of version V31. This profile generator is used in the template as of version 3.1.
What happens?
If the speed of an active profile is decelerated by reducing the override value or changing the profile, the parameter of the profile acceleration is applied instead of the profile deceleration which would have been expected to be used.
When does the problem occur?
The behaviour only occurs in case of profiles with jerk limitation (S-ramp time > 0).
The profile parameters for acceleration must differ from the ones for deceleration. In addition, the set speed of a profile is reduced online. This reduction in speed can be caused by the following different actions:
- Reduction of the speed override
- Change to a profile with lower set speed; this change can be triggered by touch probe or restart of the profile
Possible diagnostics?
The setpoint of the profile generator can be recorded by means of the Global Drive Oscilloscope. As a result, the steepness when approaching the target position and the steepness when reducing the speed can be compared with each other by applying the action mentioned above. Under the conditions mentioned above, these steepnesses differ from each other.
Short-term measures/recommendations?
None.
Evaluation
The drive decelerates slower or faster than expected but not with a steepness impermissible for the machine. If the steepness of the speed change in case of an override reduction or when changing the profile is relevant for the application, the behaviour is detected during commissioning. In many cases it is not application relevant.
