Rockwell Automation GMLC Reference Manual - Manual (Page 280)

Publication GMLC-5.2 - November 1999
Change Dynamics 243
Change Dynamics
The Change Dynamics block changes the following for a servo axis,
on-the-fly:
•
speed of trapezoidal profile moves
• speed, acceleration, and deceleration of trapezoidal profile jogs
The Change Dynamics function block resides on the Main Palette.
Changing Move Dynamics
When you select Move in the For current field, you can change the speed
of a move in progress by entering a new speed value. You cannot change
the acceleration or deceleration values for a move in progress—only its
speed. The axis ramps up to the new speed at the current acceleration rate
(if the new speed is higher than the current speed), or ramps down to the
new speed at the current deceleration rate (if the new speed is lower than
the current speed).
You can change trapezoidal profile moves to any speed at any time.
However, you can change parabolic and S-curve profile moves only to
zero speed, and then only if the axis is not decelerating
(Decel_status = 0).
Pausing Moves
You can use the Change Dynamics block to temporarily pause a move in
progress, by changing its speed to zero. Use another Change Dynamics
block with a non-zero speed value to complete the move as originally
specified.
!
ATTENTION: The Change Dynamics block affects
only trapezoidal profile moves. Other velocity profiles
cannot be changed on the fly, except to zero speed.