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Rockwell Automation 1771-QB Linear Pos. User Manual

Page 104

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Formatting Module Data (WRITES)

Chapter 7

7Ć25

The velocity smoothing constant determines how quickly the system will
change its acceleration and deceleration. The higher the value, the more quickly
acceleration and deceleration will change. A higher, faster value produces
jerkier motion, while a lower, slower value produces a smoother transition. The
following diagrams demonstrate the effect of the velocity smoothing constant.

Figure 7.34

Lower Velocity Smoothing Constant

50021

Velocity

Acceleration

Deceleration

Time

Time

If the velocity smoothing constant is set to zero, velocity smoothing is disabled,
and acceleration and deceleration will change instantaneously. The zero setting
produces the jerkiest motion.

Because of the smoother motion that can be achieved by using this feature, you
can achieve higher acceleration and deceleration levels without jerk. The
smoother motion also results in less wear and tear and less tendency to
overshoot the intended end position.