以下程勋，N600往后，求高人解释一下，什么意思

N100 PROC ELEVATOR_C1

;===========
;Definitions
;===========
N110 DEF INT al_time=10
N120 DEF INT feedZ_1A=9000, feedZ_1A_slow=2000
N150 DEF REAL P_Z1A_HOMEPOS

N160 GUD_CONTR_C1
N170 SBLOF

;===============
;Definitions IDS
;===============

;=================
;Programcode Start
;=================
N350 G01 G60 G90 G500 SOFT

N390 l_new_instr:
;================
;Instruction Loop
;================
N400 IF(DBO_C1_InstrucNo<>0)
N420    DBO_C1_InstrucNo=0
N430    G04 F0.2
N440 ENDIF
N450 G90
N455 CANCEL(12)

;=================================
;Elevator to home position
;=================================
N480 IF(DBI_C1_Elev_toHomePos==TRUE) GOTOF toHomePos
 
;=================
;AUTO-INSTRUCTIONS
;=================
;## Instruction list:
;## 98: Program stop by cycle end
;##
;## 01: Elevator to intake Position
;## 02:
;## 03:
;## 04:
;## 05:
;## 06:
;## 07:
;## 08:
;## 09:
;## 10:
;## 11: Elevator to runout Position
;## 12:
;## 13:
;## 14:
;## 21:

N500 IF(DBI_C1_AUTO_mode==TRUE)
N510   CASE DBI_C1_InstrucNo OF 1 GOTOF Elev_to_intake_pos 11 GOTOF Elev_to_runout_pos
N530   CASE DBI_C1_InstrucNo OF 98 GOTOF stop_on_cycle_end          
N540 ENDIF

;=====================
;Channel in JOG or MDI
;=====================
N600 IF (DBI_C1_AUTO_mode==TRUE) AND (DBI_Machine_AUTO_mode==TRUE)
N610    G04 F0.1
N620    GOTOB l_new_instr
N630 ENDIF
N640 STOPRE
N650 M_25_in_Homepos
N660 DBO_C1_InstrucNo=0
N670 G04 F0.2
N680 M30

N700 stop_on_cycle_end:
;====================================
;Instr. 98: Program stop on cycle end
;====================================
;Definition Homepos
N700 IF(DBI_C1_part_present==FALSE) AND (DBI_C1_no_part_present==FALSE)
N710    WHEN TRUE DO SETAL(066221) DBO_C1_Cyc_Alarm
N720    M00
N730 ENDIF
N740 IF DBI_C1_part_present==TRUE
N750    P_Z1A_HOMEPOS=P_Z1A_RUNOUT
N760 ENDIF
N770 IF DBI_C1_no_part_present==TRUE
N780    P_Z1A_HOMEPOS=P_Z1A_INTAKE
N790 ENDIF
N800 SBLON
N810 DBO_C1_InstrucNo=98
N820 MSG("Elevator ELV2 Program stop by cycle end")
N825 ID=12 WHENEVER((DBI_C1_Enab_from_intake==FALSE) OR (DBI_C1_Enable_from_runout==FALSE) OR (DBI_C1_Enable_part_in_pos==FALSE)) DO $AA_OVR[Z_1A]=0
N830 G1 G60 POS[Z_1A]=P_Z1A_HOMEPOS FA[Z_1A]=feedZ_1A
N840 STOPRE
N835 CANCEL(12)
N850 M_25_in_Homepos
N860 DBO_C1_InstrucNo=0
N870 G04 F0.2
N880 M30

N900 toHomePos:
;================================================
;Instr.99: Elevator to homeposition
;================================================
;Definition Homepos
N910 IF(DBI_C1_part_present==FALSE) AND (DBI_C1_no_part_present==FALSE)
N920    WHEN TRUE DO SETAL(066221) DBO_C1_Cyc_Alarm
N930    M00
N940 ENDIF
N950 IF DBI_C1_part_present==TRUE
N960    P_Z1A_HOMEPOS=P_Z1A_RUNOUT
N970 ENDIF
N980 IF DBI_C1_no_part_present==TRUE
N985    P_Z1A_HOMEPOS=P_Z1A_INTAKE
N986 ENDIF
N987 SBLON
N988 DBO_C1_InstrucNo=99
N989 MSG("Elevator ELV2 to homeposition")
N825 ID=12 WHENEVER((DBI_C1_Enab_from_intake==FALSE) OR (DBI_C1_Enable_from_runout==FALSE) OR (DBI_C1_Enable_part_in_pos==FALSE)) DO $AA_OVR[Z_1A]=0
N990 G1 G60 POS[Z_1A]=P_Z1A_HOMEPOS FA[Z_1A]=feedZ_1A
N991 STOPRE
N835 CANCEL(12)
N992 M_25_in_Homepos
N993 DBO_C1_InstrucNo=0
N994 G04 F0.2
N995 M30

N1000 Elev_to_intake_pos:
;===============================================================
;Instr. 1: Elevator to intake position
;===============================================================
N1010 SBLON
N1020 DBO_C1_InstrucNo=1
N1030 MSG("Elevator ELV2 to intake position")
N1035 ID=12 WHENEVER((DBI_C1_Enab_from_intake==FALSE) OR (DBI_C1_Enable_from_runout==FALSE) OR (DBI_C1_Enable_part_in_pos==FALSE)) DO $AA_OVR[Z_1A]=0
N1040 POS[Z_1A]=P_Z1A_INTAKE G01 G60 FA[Z_1A]=feedZ_1A
N1050 STOPRE
N1055 CANCEL(12)
N1060 M_25_in_Homepos
N1080 MSG("")
N1090 GOTOB l_new_instr

N1100 Elev_to_runout_pos:
;===============================================================
;Instr. 11: Elevator to runout position
;===============================================================
N1110 SBLON
N1120 DBO_C1_InstrucNo=11
N1130 MSG("Elevator ELV2 to runout position")
N1135 ID=12 WHENEVER((DBI_C1_Enab_from_intake==FALSE) OR (DBI_C1_Enable_from_runout==FALSE) OR (DBI_C1_Enable_part_in_pos==FALSE)) DO $AA_OVR[Z_1A]=0
N1140 POS[Z_1A]=P_Z1A_RUNOUT G01 G60 FA[Z_1A]=feedZ_1A
N1150 STOPRE
N1155 CANCEL(12)
N1160 M_25_in_Homepos
N1180 MSG("")
N1190 GOTOB l_new_instr