Siemens SINUMERIK 840Di Function Manual page 1626

Detailed Description
2.1 Path feedrate F
Retraction direction
The method for defining the retraction direction is controlled in conjunction with the variable
ALF using the following keywords:
• LFTXT
• LFWP
These G functions can always be programmed.
The default setting for NC Reset and/or NC Start is specified in machine data:
MD20150 GCODE_RESET_VALUES.
In the plane of the retraction movement, ALF is used, as before, to program the direction in
discrete steps of 45 degrees. With LFTXT, retraction in the tool direction was defined for
ALF=1.
With LFWP the direction in the working plane is derived from the following assignment:
G17:
G18:
G19:
Note
The extension for programming the plane of the retraction movement can be used
independently of thread cutting.
2-18
The plane of the retraction movement is determined by the path tangent and the tool
direction. This G code (default setting) is used to program the response on a fast lift.
For information about ALF programming, refer to:
References:
/PGA/ Programming Guide, Advanced
/FB1/ Description of Functions, Basic Machine; Mode Group, Channel, Program
Operation (K1);
Chapter: Asynchronous Subroutines (ASUBs), Interrupt Routines
The plane of the retraction movement is the active working plane selected with G codes
G17, G18 or G19. The direction of the retraction plane is independent of the path tangent.
This allows a fast lift to be programmed parallel to the axis.
X/Y plane
Z/X plane
Y/Z plane
Retraction in X direction
ALF=1
Retraction in Y direction
ALF=3
Retraction in Z direction
ALF=1
Retraction in X direction
ALF=3
Retraction in Y direction
ALF=1
Retraction in Z direction
ALF=3
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
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