Siemens SINUMERIK 840D sl Function Manual page 60

W1: Tool offset
2.5 2D tool radius compensation
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
P is at Z=0. The point defined by DISCL must, therefore, lie between these two points.
3
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
End point P
P can be determined by the end point of the next traversing block.
4
Further blocks (dummy blocks) can be inserted between the SAR block and the next traversing
block without moving the geometry axes.
60
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 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
can be programmed in the actual SAR block.
4
, 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
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 by
1
with reference to the
4
Function Manual, 06/2019, A5E47435126B AA
is greater
2
Tools