Siemens Sinumerik 840D sl Programming Manual page 225

The retraction motion can be programmed via:
● Retraction path and retraction direction (relative)
● Retraction position (absolute)
Note
NC stop signals
The following NC stop signals do not trigger a rapid retraction during thread cutting:
● 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= :
LFTXT
LFWP:
Fundamentals
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
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.
The retraction direction is controlled in conjunction with ALF with G functions
LFTXT and LFWP.
The plane in which the retraction motion is executed is calculated from
LFTXT:
the path tangent and the tool direction (default setting).
The plane in which the retraction motion is executed is the active working
LFWP:
plane.
Motion commands
10.10 Thread cutting
225