Siemens SINUMERIK 840DE

Programming Motion Commands
4.19 Stop with thread cutting(LFOF, LFON, LFTXT, LFWP, LFPOS)
Fundamentals
4-62 Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
Note
LFON or LFOF can always be programmed, they are evaluated only during thread cutting
(G33).
Example of enabling fast retraction in tapping
N55 M3 S500 G90 G18
;Active machining plane
... ;Approach start position
N65 MSG ("thread cutting") ;Tool infeed
MM_THREAD:
N67 $AC_LIFTFAST=0 ;Reset before beginning of
;thread
N68 G0 Z5
N68 X10
N70 G33 Z30 K5 LFON DILF=10 LFWP ALF=3
;Enable fast retraction for thread
;cutting
Retraction path =10mm, retraction plane Z/X (due to G18)
Retraction direction -X (with ALF=3; retraction direction
+X)
N71 G33 Z55 X15 K5
N72 G1 ;Deselect thread cutting
N69 IF $AC_LIFTFAST GOTOB MM_THREAD ;If thread cutting was ;interrupted
N90 MSG ("")
...
N70 M30
Example of deactivating fast retraction before tapping.
N55 M3 S500 G90 G0 X0 Z0
...
N87 MSG ("tapping")
N88 LFOF
;Deactivate fast retraction before
;tapping.
N89 CYCLE... ;Tapping cycle with G33
N90 MSG ("")
...
N99 M30