Corrected from:Library: L_MC1P_MotionControlBasic (FAST Motion) from V03.23.00.159
(Update via Package Manager)
Response of the new version:
For the jogging function (ManualJog), the behaviour of the profile generator when reversing has now been changed as follows:
- When reversing, the specified deceleration is now used for the deceleration phase and
- for the subsequent blending process, the specified blending.
- Now the described overrunning of the SW end positions no longer occurs for this reason.
For other movement functions, e.g. Move FBs, it remains the same as before that the entire reversing process is carried out with the specified acceleration.
Justification:
Compliance with the compatibility of the movement behavioursw with previous versions was assessed as more important for these movement functions. The probability of occurrence in practice for the described behaviour with relevant effects on the machine, is assessed as very low for the other movement functions.
What happens?
When reversing after reversing to a movement in the opposite direction, the drive sporadically moves beyond the SW limit.
When does the behaviour occur?
L_MC1P_ManualJog and all Move FBs:
- Jogging mode or motion mode with activated monitoring of the software end positions.
- The deceleration at FB input 'lrDeceleration' is set greater than the acceleration at FB input 'lrAcceleration'.
- During a movement and shortly before reaching the SW end position, a new travel command is issued for a movement in the opposite direction.
Background:
The distance to the SW end position is monitored during jog or motion operation. Each movement is stopped at the SW end position at the latest, with the delay set at the FB input 'lrDecceleration'.
If a new travel command is issued in the opposite direction during the movement to the SW end position, reversing is required. Reversing (stopping and accelerating in the opposite direction) is done continuously with the acceleration value set at FB input 'lrAcceleration'.
If the reversing process takes place close to the SW end position, this can cause the SW end position to be overrun, because the use of the smaller acceleration value for stopping increases the braking distance compared to the originally used deceleration value.
Which products are affected?
Library: L_MC1P_MotionControlBasic (FAST Motion)
Short-term measures, Evaluation/Recommendations:
With the following applicative measure, the described behaviour can be avoided:
Calculate the required braking distance in the application, starting from the current speed to standstill, using the set values at the FB inputs lrAcceleration and lrJerk for ramping down.
If the available distance from the actual position to the SW end position is smaller than the calculated required braking distance, a movement in the opposite direction may only be commissioned after the standstill has been reached.
Automatic Translation
