Rockwell Automation Publication MOTION-UM003K-EN-P - January 2019 323
Out of Box Configuration for PowerFlex Drives Appendix B
Look For
Cause
When you use an S-curve profile, jerk determines the acceleration and
deceleration time of the axis:
• An S-curve profile has to get acceleration to 0 before the axis can slow
down.
• If you reduce the acceleration, it takes longer to get acceleration to 0.
• In the meantime, the axis continues past its initial target speed.
The following trends show how the axis stops with a trapezoidal profile and an
S-curve profile.
The MAJ instruction that starts the axis
has a higher acceleration rate than the
instruction that stops the axis.
The MAJ instruction that stops the axis has
a lower acceleration rate than the
instruction that starts the axis.
S-curve profile
S-curve profile