Rockwell Automation 57C422B 2 Axis Servo Module - Manual (Page 96)

5-10 2-Axis Servo Module M/N 57C422B
5.8 Cam Mode
The following example illustrates the software necessary to
use the axis in the cam mode. The example is a time cam. It
illustrates how to calculate cam parameters and the values in
the cam table itself. It also shows how to start cam execution.
8992 !
8993 ! Compute cam parameters
8994 !
8995 ! FDBK_SCALING = encoder counts/engineering units
8996 ! CAM_CYCLE_TIME = time (in seconds) for one complete
cam cycle
8997 ! SPD = maximum speed (in engineering units)
8998 ! MAX_SPD = maximum speed (encoder counts/cam
time interval)
8999 !
9000 IF CAM_CYCLE_TIME <1915*.00125 THEN STEP_TIME=1 \GOTO 9010
9005 STEP_TIME%=CAM_CYCLE_TIME/(1915*.00125)+.999
9010 TOTAL_PTS%=CAM_CYCLE_TIME/(STEP_TIME%*.00125)+.999
9015 IF TOTAL_PTS% > 1915 THEN TOTAL_PTS%= 1915
9020 MAX_SPD=SPD*FDBK_SCALING*STEP_TIME%*.00125
9025 RETURN
9297 !
9298 ! Calculate Cam Profile Points
9299 !
9300 ADDRESS!=VARPTR!(CAM_TABLE%) \!Starting address for cam profile
9310 FOR I%=0 TO TOTAL_PTS%_1
9315 ! DATA_POINT%=change in position for next time interval
9320 IOWRITE(3, DATA_POINT%, ADDRESS!)
9325 ADDRESS!=ADDRESS! +2
9330 NEXT I%
9335 RETURN
9400 !
9497 !
9498 ! Start cam cycle
9499 !
9500 CAM_LOOPBACK%=0 !No loopback point.
9505 CAM_MODE%=9 \!Run continuously, word format
9510 CMD66%=080H \GOSUB 25000 \! Do cam profile
9515 RETURN