User manual

262 Rockwell Automation Publication MOTION-UM003F-EN-P - March 2015
Appendix C Program
Which revision do you have?
• 15 or earlier – % of Time is fixed at 100.
• 16 or later – % of Time defaults to 100% of time on projects converted
from earlier versions. For new projects, you must enter the Jerk value.
EXAMPLE
Example #1
Start Speed = 8.0 in/sec
Desired Speed = 5.0 in/sec
Desired Decel Rate = 2.0 in/sec
2
Desired Decel Jerk = 1.0 in/sec
3
Temporary Speed = (Desired Decel Rate)
2
/ Desired jerk value in Units/Sec
3
= 2.0
2
/ 1.0 =
= 4.0 in/sec
k = (8.0 - 5.0) / max(5.0, 4.0) = 3.0 / 5.0 =
= 0.6
Because k < 1, we can enter the desired Decel jerk directly in the faceplate
Instruction faceplate Decel jerk in Units/Sec
3
= 1.0 in/sec
3
EXAMPLE
Example #2
Start Speed = 13.0 in/sec
Desired Speed = 5.0 in/sec
Desired Decel Rate = 2.0 in/sec
2
Desired Decel Jerk = 1.0 in/sec
3
Temporary Speed = (Desired Decel Rate)
2
/ Desired jerk value in Units/Sec
3
= 2.0
2
/ 1.0 =
= 4.0 in/sec
k = (13.0 - 5.0) / max(5.0, 4.0) = 8.0 / 5.0 =
= 1.6
Because k > 1, we have to calculate the Decel jerk to use on the instruction
faceplate as:
Instruction faceplate Decel jerk in Units/Sec
3
=
= 1.0 in/sec
3
* 1.6 =
= 1.6 in/sec
3