Siemens SINUMERIK 840D sl Function Manual page 59

Modal G command (G340, G341), which defines the subdivision of the movement into individual blocks
from the start point to the end point
G34
0:
G34
1:
Figure 2-8
Note
Active, rotating frames are included in all cases where the position of the active plane G17 - G19
(circle plane, helix axis, infeed movements perpendicular to the active plane) is relevant.
DISR
DISRSpecifies the length of a straight approach line or the radius of an approach arc.
Retraction/approach with straight lines
On approach/retraction along a straight line, DISR specifies the distance from the cutter edge
to the start point of the contour, i.e. the length of the straight line with active TRC is calculated
as the total of the tool radius and the programmed value of DISR.
An alarm is displayed:
● If DISR is negative and the amount is greater than the tool radius (the length of the resulting
approach line is less than or equal to zero).
Retraction/approach with circles
Tools
Function Manual, 06/2019, A5E47435126B AA
The approach characteristic from P
If G247 or G347 is active (quadrant or semicircle) and start point P
plane defined by the end point P
coincides with P .
3
The circle plane or the helix axis is determined by the plane, which is active in the SAR block (G17
- G19), i.e. the projection of the start tangent is used by the following block, instead of the tangent
itself, to define the circle.
The movement from point P
before the SAR block.
The approach characteristic from P
P and P are located within the machining plane, with the result that a circle is always inserted
3 4
instead of a helix with G247 or G347.
Sequence of the approach movement depending on G340/G341
to P is shown in the figure.
0 4
, a helix is inserted instead of a circle. Point P
4
to point P takes place along two straight lines at the velocity valid
0 3
to P is shown in the figure.
0 4
W1: Tool offset
2.5 2D tool radius compensation
is outside the machining
3
is not defined or
2
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