User manual

Rockwell Automation Publication MOTION-UM003F-EN-P - March 2015 255
Appendix C
Program
This chapter describes how to program a velocity profile and jerk rate.
Program a Velocity Profile
and Jerk Rate
You can use either of these motion profiles for various instructions:
•Trapezoidal profile for linear acceleration and deceleration
•S-curve profiles for controlled jerk
Definition of Jerk
The Jerk is the rate of change of acceleration or deceleration.
The jerk parameters apply only to S-curve profile moves using these instructions:
For example, if acceleration changes from 0 to 40 mm/s
2
in 0.2 seconds, the jerk
is:
(40 mm/s
2
- 0 mm/s
2
) / 0.2 s = 200 mm/s
3
Topic Page
Program a Velocity Profile and Jerk Rate 255
Enter Basic Logic 266
Choose a Motion Instruction 268
Troubleshoot Axis Motion 271
Troubleshoot Axis Motion 271
Why does my axis overshoot its target speed? 272
Why is there a delay when I stop and then restart a jog? 275
Why does my axis reverse direction when I stop and start it? 277
Programming with the MDSC Function 279
• MAJ • MCS
• MAM • MCCD
• MAS • MCCM
• MCD • MCLM