Siemens SINUMERIK 840D sl Function Manual page 87

Conditions
The orientation movement is compressed in the following cases:
• Active orientation transformation (TRAORI)
• Active large radius circular interpolation (i.e. tool orientation is changed in the plane which
is determined by start and end orientation).
Large circle interpolation is performed under the following conditions:
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Parameter assignment
NC blocks can only be compressed if deviations are allowed between the programmed
contour and interpolated contour or between the programmed orientation and interpolated
orientation.
Compression tolerances can be used to set the maximum permissible deviation. The higher
the tolerances, the more blocks can be compressed. However, the higher the tolerances, the
more the interpolated contour or orientation can deviate from the programmed values.
Axis accuracy
For each axis, the compressor creates a spline curve which deviates from the programmed
end points of each axis by a maximum of the value set with the following machine data.
MD33100 $MA_COMPRESS_POS_TOL (maximum tolerance with compression)
Contour accuracy
The maximum contour deviations (geo axes) and tool orientation are specified via the
following setting data:
SD42475 $SC_COMPRESS_CONTUR_TOL (maximum contour deviation for compressor)
SD42476 $SC_COMPRESS_ORI_TOL (maximum angular deviation for tool orientation
compressor)
SD42477 $SC_COMPRESS_ORI_ROT_TOL (maximum angular deviation for the angle of
rotation of the tool) (only available on 6-axis machines)
Note
It is only possible to specify a maximum angular deviation for tool orientation if an orientation
transformation (TRAORI) is active.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
MD21104 $MC_ORI_IPO_WITH_G_CODE = 0,
ORIWKS is active and
orientation is programmed with the help of vectors (with A3, B3, C3 or A2, B2, C2).
MD21104 $MC_ORI_IPO_WITH_G_CODE = 1 and
ORIVECT or ORIPLANE is active.
The tool orientation can be programmed either as a direction vector or with rotary axis
positions. If one of the G-codes ORICONxx or ORICURVE is active, or if polynomials for
the orientation angles (PO[PHI] and PO[PSI]) are programmed, no large circle
interpolation will be executed.
F2: Multi-axis transformations
1.9 Orientation
87