Siemens SINUMERIK 840D sl Operating Manual page 346

Programming technology functions (cycles)
8.3 Contour turning
Parameter Description
Direction in front Direction of the contour element towards the starting point:
of the contour
In the negative direction of the horizontal axis
•
In the positive direction of the horizontal axis
•
In the negative direction of the vertical axis
•
In the positive direction of the vertical axis
•
Additional You can enter additional commands in the form of G code for each contour element.
commands You can enter the additional commands (max. 40 characters) in the extended
parameter screens ("All parameters" softkey). The softkey is always available at the
starting point, it only has to be pressed when entering additional contour elements.
You can program feedrates and M commands, for example, using additional G code
commands. However, carefully ensure that the additional commands do not collide with
the generated G code of the contour and are compatible with the machining type
required. Therefore, do not use any G code commands of group 1 (G0, G1, G2, G3), no
coordinates in the plane and no G code commands that have to be programmed in a
separate block.
The contour is finished in continuous-path mode (G64). As a result, contour transitions
such as corners, chamfers or radii may not be machined precisely.
If you wish to avoid this, then it is possible to use additional commands when
programming.
Example: For a contour, first program the straight X parallel and then enter "G9" (non-
modal exact stop) for the additional command parameter. Then program the Z-parallel
straight line. The corner will be machined exactly, as the feedrate at the end of the X-
parallel straight line is briefly zero.
Note:
The additional commands are only effective for finishing!
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Operating Manual, 03/2013, 6FC5398-8CP40-3BA1
Unit
Turning