User`s manual

9-6 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – October 2000 GFK-1742A
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following the master command. Note that the Accel Ramp and Make-Up Time feature could
be used to allow the follower axis to catch up to the master axis if required.
4. Once the follower is enabled, the PLC sends the
Execute Motion Program n
%Q bit to start
execution of the selected program for the follower axis. At the time the program is selected,
Program Command Position will be set to program reference position (0) because the follower
is enabled. Program execution is then relative to the moving part edge as the follower axis
tracks the part. Program Command Position now contains the position of the follower axis
relative to the part edge and
Actual Position
indicates the total distance the follower axis has
moved from the Home point (master +/– program commands).
5. At the end of program, the PLC turns
Enable Follower
%Q bit OFF and loops back to step 1
to repeat for next part.
Note
Since the DSM314 saved the Follower enable input trigger
Commanded
Position
in a parameter register (#226 for axis 1, #234 for axis 2), step 1 this
time could be used to execute another program with an absolute move command
back to the parameter value position and continuing with step 2. In this case,
the
Moving
and
In Zone
%I bit indications could be used to indicate when step 1
is complete.
This method is possible because the Program Command Position is set to the
Actual Position + Position Error
when execute motion program is commanded
with the follower disabled.