Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 67)

3–45 Programming and Operation
Publication 1771-UM002A–EN–P – May 2000
The following three examples show how this equation can be used.
Example Problem 1: Single-step mode or independent mode.
For the next move of a move profile, the change in move position
from beginning to end (DELPOS) must be 26k pulses. Determine
the maximum allowable final rate (FR) when using equal ramp and
decel times of 4 seconds.
The parameters of the equation (IR, FR, RT and DELPOS) and a
sketch of the move are shown in Figure 3.20.
Figure 3.20
Single Step or Independent Mode
Rate
FR
IR
RT DT
DEL POS
Start
Position Final
Position
10530
Position
20 ms
Solution
Write down the known facts.
1. RT = DT = 4 seconds
DELPOS = 26k pulses
IR = 0 (The initial rate of a move in the single step or
independent mode is zero by definition.)
Find FR, the maximum final rate.
4(FR + 0)
+ FR + 0.02 < 26k
2 2
4
Choose a value for FR, say 10k pulses per second.