Siemens SINUMERIK 840D sl Programming Manual page 168

Special Motion Commands
5.2 Spline interpolation (ASPLINE, BSPLINE, CSPLINE, BAUTO, BNAT, BTAN)
Parameters
ASPLINE
BSPLINE
CSPLINE
A, B and C splines are modally active and belong to the group of motion commands.
The tool radius offset may be used.
Collision monitoring is carried out in the projection in the plane.
Note
Parameters for A-SPLINE and C-SPLINE
For the Akima spline (A spline) and the Cubic spline (C spline), restrictions for the transition
behavior at the start and the end of the spline curve can be programmed.
These restrictions for the transition behavior are divided into two groups with statements
each with three commands as follows:
Start of spline curve:
BAUTO
BNAT
BTAN
End of spline curve:
EAUTO
ENAT
ETAN
5-4
The Akima spline passes as tangent through the intermediate
points.
The B spline does not pass directly through the control points
but only near them. The programmed positions are not
interpolation points but only control points.
Cubic spline with transitions to the interpolation points both
tangentially and in terms of curvature.
No command input; start is determined by the position of the
first point
Zero curvature
Tangential transition to preceding block (initial setting)
No command input; end is determined by the position of the
last point
Zero curvature
Tangential transition to next block (initial setting)
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
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