Siemens SINUMERIK 840D sl Function Manual page 1413

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
Approach/retraction with circles
DISR indicates always the radius of the tool center point path. If tool radius compensation is
activated, a circle is generated internally, the radius of which is dimensioned such that the tool
center path is derived, in this case also, from the programmed radius.
An alarm is output on approach and retraction with circles:
● If the radius of the circle generated internally is zero or negative
● If DISR is not programmed
● If the radius value ≤ 0.
DISCL
DISCLspecifies the distance from point P2 from the machining plane.
If the position of point P
to the circle plane, the value must be programmed in the form DISCL = AC( ....).
If DISCL is not programmed, points P
contour is mapped from P
The system checks that the point defined by DISCL lies between P
movements, which have a component perpendicular to the machining plane (e.g., infeed
movements, approach movements from P
sign. It is not permitted to change direction. An alarm is output if this condition is violated.
On detection of a direction reversal, a tolerance is permitted that is defined by the machine
data:
MD20204 $MC_WAB_CLEARANCE_TOLERANCE (direction reversal on SAR).
However, if P
to this tolerance, it is assumed that P
Example:
An approach is made with G17 starting at position Z=20 of point P
by P
MD20204=0.010. If P
that the value 20.0 or 0.0 is programmed. The alarm is output if the Z position of P
than 20.010 or less than -0.010.
Depending on the relative position of start point P
machining plane, the infeed movements are performed in the negative (normal for approach)
or positive (normal for retraction) direction, i.e., with G17 it is possible for the Z component of
end point P
Programming the end point P
Possible ways of programming the end point P
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
is to be specified by an absolute reference on the axis perpendicular
2
to P
1
is outside the range defined by P
2
is at Z=0. The point defined by DISCL must, therefore, lie between these two points.
3
is between 20.000 and 20.010 or between 0 and -0.010, it is assumed
2
to be greater than that of start point P
4
(or P for retraction) generally with X... Y... Z...
4 0
18.5 Tool radius compensation 2D (TRC)
, P and P are identical with G340 and the approach
1 2 3
.
4
to P ), this component must have the same leading
3 4
and P
1 3
is in the plane defined by P
2
and end point P
0
.
0
for approach
4
W1: Tool offset
and P , i.e., in all
1 3
and the deviation is less than or equal
and/or P .
1 3
. The SAR plane defined
1
with reference to the
4
is greater
2
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