User Manual
Chapter 7
GFK-1742F
Jan 2020
Programmed Motion
204
Jump Stop
A jump stop is a stop that is caused by a jump. When a jump stop occurs, the current
programmed acceleration and acceleration mode are used. Note that s-curve motion will
achieve constant velocity before beginning to decelerate. See the s-curve jump examples
for more details. There are two ways of generating a jump stop each described below.
A conditional JUMP triggered during a PMOVE will always generate a jump stop. Because a
PMOVE always stops before continuing to a subsequent motion, a jump stop always occurs
when a jump takes place during a PMOVE.
When a conditional jump trigger occurs during a CMOVE, however, a jump stop will not
occur if the motion programmed at the jump destination is a PMOVE or CMOVE
representing sufficient distance in the same direction. A jump stop will occur if the PMOVE
or CMOVE at the jump destination does not represent sufficient distance or represents
motion in the opposite direction.
In an s-curve move, a jump stop will do one of two things. If the jump takes place after the
midpoint of the acceleration or deceleration, the acceleration or deceleration is completed
before the jump stop is initiated. If the jump occurs before the midpoint of the acceleration
or deceleration, the profile will immediately begin leveling off. Once acceleration or
deceleration is zero, the jump stop begins. See the s-curve jump examples.
Example 10: Jump Stop
The following is an example conditional jump with a jump stop. An enhancement on
Example 5, DWELL, would be to watch an external CTL bit that would indicate a problem
with the positive motion. If the CTL bit never turns on, the profile for the following program
will be identical to the profile shown in the DWELL example. If the CTL bit turned on during
the first PMOVE or the DWELL, the reverse movement would immediately commence.
The following profile would appear if the CTL bit turned on during the first PMOVE, at the
dashed line. Because the first move completed early due to the CTL bit turning on, the
second move would not have to move as far to get back to 0 position as it did in the DWELL
example. Note that because the motion programmed at the jump destination is in the
opposite direction as the initial motion, the profile would be identical if the moves were
CMOVEs instead of PMOVEs.
Figure 81: Jump Stop