Corrected from:
Response of the new version:
The target will be reached correctly now.
What happens?
When activating a safely limited speed (SLS) at the LS_Limiter system block during a running positioning process, the target position is overtravelled. If the drive traverses in negative direction, it reverses. In the limited traversing range, the software limit position monitoring responds. In the unlimited or modulo traversing range, the drive continues rotating.
The same behaviour can be monitored if one of the limiting parameters (C2703, C2705, C2706) is changed during positioning.
When does this behaviour occur?
The behaviour occurs under the following conditions:
The limit setpoint is changed by changing a parameter in C2703, C2705, C2706 or by activating a limited speed during an active profile generation (POS_bActive=TRUE).
Profile generation is jerk-reduced; S-ramp time > 1ms
Which products are affected?
Short-term measures:
Any change of the limiting parameters and the activation of a limited speed must be effected before positioning is started. If this cannot be ensured, the jerk reduction must be deactivated.
The behaviour does not occur with the previous firmware versions (e.g. 10.x or 11.x).
Evaluation/recommendations:
- Overtravelling the target position and/or reversing may lead to collisions in the traversing range or at mechanical limits. The transported material may be damaged.
- The behaviour should always be detected during commissioning as part of checking the safety functions.
- Incompatible with previous versions. In the event of a device replacement in the case of servicing, the behaviour will not necessarily be detected immediately because the safety functions will not be tested again in detail.
- In general, limiting parameters are not changed during an active positioning process.
- Applications in which SLS is always activated from standstill are not concerned. This is frequently done.
- The behaviour does not occur during manual control. Here, the drive stops, as expected, no later than at the software limit position without response of a monitoring function.
