Siemens sinumerik 840d Programming Manual page 74

Flexible NC Programming
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1.14 Interrupt routine
840D 840D
NCU 571 NCU 572
NCU 573
Retraction movement in SW 4.3 and higher
The direction of the retraction movement is
programmed by means of the G code LFTXT or
LFWP with the variable ALF.
• LFTXT
The plane of the retraction movement is
determined from the path tangent and the tool
direction. This G code (default setting) is
presently used for programming the behavior for
fast lift.
• LFWP
The plane for the retraction movement is the
active working plane which is selected by means
of G codes G17, G18 or G19. The direction of the
retraction movement is not dependent on the
path tangent. Thus it is possible to program an
axis-parallel fast lift.
In the retraction movement plane, ALF is used to
program the direction in discrete steps of
45 degrees as was the case formerly. With LFTXT
retraction in tool direction is defined for ALF=1.
With LFWP the direction in the working plane is
according to the following:
• G17: X/Y plane
• G18: Z/X plane
• G19: Y/Z plane
1-74
810D 840Di
ALF=1 retraction in X direction
ALF=3 retraction in Y direction
ALF=1 retraction in Z direction
ALF=3 retraction in X direction
ALF=1 retraction in Y direction
ALF=3 retraction in Z direction
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) − 04.00 Edition
02.98
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