Siemens Sinumerik 840D sl Programming Manual page 252

Special Motion Commands
4.2 Spline interpolation (ASPLINE, BSPLINE, CSPLINE, BAUTO, BNAT, BTAN, EAUTO, ENAT, ETAN, PW, SD,
Further Information
Advantages of spline interpolation
By using spline interpolation, the following advantages can be obtained contrary to using
straight line blocks G01:
• The number of part program blocks required to describe the contour are reduced
• Soft, curve characteristics that reduce the stress on the mechanical system at transitions
between part program blocks.
Properties and use of the various spline types
Spline type
A spline
252
Properties and use
Properties:
• The passes precisely through the specified intermediate points along the
curve.
• The curve characteristic is tangential, but does not have continuous
curvature.
• Produces hardly any undesirable oscillations.
• The area of influence of changes to intermediate points along the curve is
local. This means that a change to an intermediate point along the curve only
affects up to max. 6 adjacent intermediate points.
Application:
The A spline is especially suitable for interpolating curves with large changes in
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
Job planning