Siemens Sinumerik 840D sl Programming Manual page 367

Programming tool orientation using rotary axis positions
Tool orientation can be also specified using rotary axis positions, e.g. with the following
structure:
N... X=<...> Y=<...> Z=<...> A=<...> B=<...> C=<...> THETA=<...> F=<...>
In this case, compression is executed in two different ways, dependent on whether large
radius circular interpolation is executed. If no large radius circular interpolation takes place,
then the compressed change in orientation is represented in the usual way by axial
polynomials for the rotary axes.
Contour accuracy
Depending on the selected compression mode (MD20482 $MC_COMPRESSOR_MODE)
either the configured axis-specific tolerances (MD33100 $MA_COMPRESS_POS_TOL) or
the following channel-specific tolerances – set using setting data – are effective for the
geometry axes and orientation axes for compression:
SD42475 $SC_COMPRESS_CONTUR_TOL (maximum contour deviation)
SD42476 $SC_COMPRESS_ORI_TOL (maximum angular deviation for tool orientation)
SD42477 $SC_COMPRESS_ORI_ROT_TOL (maximum angular deviation for the angle of
rotation of the tool) (only available on 6-axis machines)
References:
Function Manual Basic Functions; 3 to 5-Axis Transformation (F2),
Chapter: "Compression of the orientation"
Activation/deactivation
Compressor functions are activated using the modal G codes COMPON, COMPCURV or
COMPCAD.
COMPOF terminates the compressor function.
See " NC block compression (COMPON, COMPCURV, COMPCAD, COMPOF) [Page 259] ".
Note
Orientation motion is only compressed when large radius circular interpolation is active (i.e.
tool orientation is changed in the plane which is determined by start and end orientation).
Large radius circular interpolation is executed under the following conditions:
• MD21104 $MC_ORI_IPO_WITH_G_CODE = 0,
ORIWKS is active and
the orientation is programmed as a vector (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.
Job planning
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
6.6 Compression of the orientation (COMPON, COMPCURV, COMPCAD)
Transformations
367