Siemens SINUMERIK 840DE Programming Manual page 168

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