User`s manual

7-22 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
7
t
v
v
t
Types of Acceleration
Linear Acceleration
A sample linear move profile that plots velocity versus time is shown in Figure 7-1. As
illustrated, a linear move uses constant (linear) acceleration. The area under the graph represents
the distance moved.
ACCEL 1000
VELOC 2000
PMOVE 6000, INCR, LINEAR
Figure 7-1. Sample Linear Motion
S-Curve Acceleration
An S-Curve motion sample, plotting velocity versus time, is shown below. As illustrated, S-
Curve acceleration is non-linear. When the move begins, the acceleration starts slowly and
builds until it reaches the programmed acceleration. This should be the midpoint of the
acceleration. Then, the acceleration begins decreasing until it is zero, at which time the
programmed velocity has been reached. An S-Curve move requires twice the time and distance
to accelerate and decelerate that a comparable linear move needs. The area under the graph
represents the distance moved.
ACCEL 2000
VELOC 2000
PMOVE 8000, INCR, S-CURVE
Figure 7-2. Sample S-Curve Motion