Rockwell Automation 57C422B 2 Axis Servo Module - Manual (Page 92)

5-6 2-Axis Servo Module M/N 57C422B
5.4 Homing
The following is a sample routine that will home the axis. If
the setup parameters defined in section 5.3 are used, the
axis will first move in the direction of decreasing encoder
counts (negative) towards the home limit switch. After the
home limit switch has been tripped, the axis will then move at
slow speed in the opposite direction until it reaches the
marker pulse. This same routine will correctly perform all of
the other home sequences based on the configuration data
in register 2.
4991 !
4992 ! Homing Sequence
4993 !
4994 ! FDBK-SCALING
= encoder counts/engineering unit
4995 ! FDBK-POS = position (in engineering units)
4996 ! SPD = velocity (in engineering units)
4997 ! ACCEL = acceleration (in engineering units)
4998 ! FAULT@ = fault status
4999 !
5000 HOME_SPD!=(SPD/100.)*FDBK_SCALING*65.536
\!Slow home velocity
5010 CMD_POS!=FDBK_POS*FDBK_SCALING \!Home position
5020 CMD_VEL! =(SPD/10.)*FDBK_SCALING*65.536 \!Fast home velocity
5030 CMD_ACC!=(ACCEL/4.)*FDBK_SCALING*.065536 \!Maximum accel
5040 CMD_DEC!=CMD_ACC! \!Maximum decel
5050 MODES%=MODES% AND 0FEH \!Disable fdbk
5060 DELAY 10 TICKS
5070 MODES%=MODES% OR 1
\!Enable fdbk loop
5080 CMD66%=4 \GOSUB 25000 \!HOME COMMAND
5090 IF FAULT@ THEN RETURN
5100 DELAY 20 TICKS VF NOT HOME_COMPLETE@ THEN GOTO 5100
5110
DELAY 20 TICKS
5120 FAULT@= (FAULTS% AND 037FH) < > 0
5130 RETURN