Fast Retraction During Thread Cutting (Lfon, Lfof, Dilf, Alf, Lftxt, Lfwp, Lfpos, Polf, Polfmask, Polfmlin) - Siemens SINUMERIK 840D sl Programming Manual

2.9.10.4 Fast retraction during thread cutting (LFON, LFOF, DILF, ALF, LFTXT, LFWP, LFPOS,
POLF, POLFMASK, POLFMLIN)
The "Rapid retraction during thread cutting (G33)" function can be used to interrupt thread
cutting without causing irreparable damage in the following situations:
● NC stop initiated via DB21, ... DBX7.3
● NC stop implicitly initiated via an alarm
● Switching a fast input (Page 544)
The retraction motion can be programmed via:
● Retraction path and retraction direction (relative)
● Retraction position (absolute)
Note
NC stop signals
During thread cutting, the following NC stop signals do not trigger a rapid retraction:
● DB21, ... DBX3.4 (NC stop axes plus spindles)
● DB21, ... DBX7.2 (NC stop at the block limit)
Tapping
The "Rapid retraction" function cannot be used with tapping (G331/G332).
Syntax
Enable rapid retraction, retraction motion via retraction path and retraction direction:
G33 ... LFON DILF=<value> LFTXT/LFWP ALF=<value>
Enable rapid retraction, retraction motion via retraction position:
POLF[<axis identifier>]=<value> LFPOS
POLFMASK/POLFMLIN(<axis 1 name>,<axis 2 name>, etc.)
G33 ... LFON
Disable rapid retraction during thread cutting:
LFOF
Meaning
LFON:
LFOF:
DILF= :
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Enable rapid retraction during thread cutting (G33)
Disable rapid retraction during thread cutting (G33)
Define length of retraction path
The value preset during MD configuration (MD21200 $MC_LIFTFAST_DIST) can be
modified in the part program by programming DILF.
Note:
The configured MD value is always active following NC-RESET.
Fundamentals
2.9 Motion commands
231