Siemens SINUMERIK 840D sl Programming Manual page 232

Fundamentals
2.9 Motion commands
LFTXT
LFWP:
ALF= :
LFPOS:
POLFMASK:
POLFMLIN:
POLF[]:
<axis
identifier>:
Note
LFON or LFOF can always be programmed, but the evaluation is performed exclusively during
thread cutting (G33).
Note
POLF with POLFMASK/POLFMLIN are not restricted to thread cutting applications.
232
The retraction direction is controlled in conjunction with ALF with G
commands 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.
The direction is programmed in discrete degree increments with ALF in the plane of
the retraction motion.
With LFTXT, retraction in the tool direction is defined for ALF=1.
For LFWP, the direction in the machining plane is derived from following assignment:
● G17 (X/Y plane)
ALF=1 ; Retraction in the X direction
ALF=3 ; Retraction in the Y direction
● G18 (Z/X plane)
ALF=1 ; Retraction in the Z direction
ALF=3 ; Retraction in the X direction
● G19 (Y/Z plane)
ALF=1 ; Retraction in the Y direction
ALF=3 ; Retraction in the Z direction
For additional information on the programming options with ALF see Chapter "Tra‐
versing direction for fast retraction from the contour (Page 546)".
Retraction of the axis declared with POLFMASK or POLFMLIN to the absolute axis
position programmed with POLF.
Release of axes (<axis 1 name>,<axis 1 name>, etc.) for independent
retraction to absolute position.
Release of axes for retraction to absolute position in linear relation
Note:
Depending on the dynamic response of all the axes involved, the linear relation can‐
not always be established before the lift position is reached.
Define absolute retraction position for the geometry axis or machine axis in the index
Effective: Modal
In the case of geometry axes, the assigned value is interpreted as
=<value>:
a position in the workpiece coordinate system. In the case of ma‐
chine axes, it is interpreted as a position in the machine coordinate
system.
The values assigned can also be programmed as incremental di‐
mensions:
=IC<value>
Identifier of a geometry axis or machine axis.
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming