Rockwell Automation GMLC Reference Manual - Manual (Page 110)

Publication GMLC-5.2 - November 1999
Defining Position 73
S Curve
You will most frequently use the S curve velocity profiles when the stress
on the mechanical system and load needs to be minimized. However, the
S curve velocity profile sacrifices acceleration and deceleration time
compared to the trapezoidal. In addition, the speed (velocity) of S curve
motion cannot be changed once the motion is started—except to zero—
and the same acceleration and deceleration must be used. (Any
deceleration value is ignored in subsequent Move or Jog Axis blocks.)
Velocity
Time
Jerk
Accel
Time
Time