Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 68)

3–46 Programming and Operation
Publication 1771-UM002A–EN–P – May 2000
4(10k + 0)
+ 10k
+ 0.02 < 26k
2 2
4
20k + 20.2k <26k
40.2k <26k This exceeds the constraint.
The selected value of 10k was too large. Try FR = 6k.
4(6k + 0)
+ 6k
+ 0.02 < 26k
2 2
4
12K + 12.12K <26k
24.12k <26k This is within the constraint.
The final rate of 6k pulses per second is allowable and can be used.
Any value greater than approximately 6.4k pulses would cause a
programming error when the move is executed.
Example Problem 2: Continuous Mode (except the last move)
Determine the minimum final position (shortest allowable travel) of
a move when the final position and final rate of the previous move
were 100k pulses and 2k pulses per second, respectively, and the
ramp time and final rate of the current move are RT = 3 seconds and
FR = 10k pulses per second.
The parameters of the equation (IR, FR, RT and DELPOS) and a
sketch of the move are in Figure 3.21.
Figure 3.21
Continuous Mode (Except the Last Move)
Rate
FR
IR
RT
DEL POS
10532
Position
Start
Position Final
Position
20 ms
Solution: Write down the know facts.