Galil Motion Control CDS-3310, User Manual

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CDS-3310 Chapter 6 Programming Motion
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Example Motion 1:
The host program determines that the first target for the controller to move to is located at 5000
encoder counts. The acceleration and deceleration should be set to 150,000 cts/sec
2
and the velocity is
set to 50,000 cts/sec. The command sequence to perform this is listed below.
COMMAND DESCRIPTION
PT1 Place the X axis in Position tracking mode
AC150000
Set the X axis acceleration to 150000 cts/sec
2
DC150000
Set the X axis deceleration to 150000 cts/sec
2
SP50000 Set the X axis speed to 50000 cts/sec
PA5000 Command the X axis to absolute position 5000 encoder counts
Figure 1 Position vs Time (msec) Motion 1
Example Motion 2:
The previous step showed the plot if the motion continued all the way to 5000, however partway
through the motion, the object that was being tracked changed direction, so the host program
determined that the actual target position should be 2000 cts at that time. Figure 2 shows what the
position profile would look like if the move was allowed to complete to 2000 cts. The position was
modified when the robot was at a position of 4200 cts. Note that the robot actually travels to a distance
of almost 5000 cts before it turns around. This is a function of the deceleration rate set by the DC
command. When a direction change is commanded, the controller decelerates at the rate specified by
the DC command. The controller then ramps the velocity in up to the value set with SP in the opposite
direction traveling to the new specified absolute position. In figure 3 the velocity profile is triangular
because the controller doesn’t have sufficient time to reach the set speed of 50000 cts/sec before it is
commanded to change direction.