Siemens SINUMERIK 840D sl Programming Manual page 275

4.2 Spline interpolation (ASPLINE, BSPLINE, CSPLINE, BAUTO, BNAT, BTAN, EAUTO, ENAT, ETAN, PW, SD, PL)
Note
An alarm is output if the tolerated value is undershot and likewise when one of the axes
involved in the spline is programmed as a positioning axis.
Combine short spline blocks
Spline interpolation can result in short spline blocks, which reduce the path velocity
unnecessarily. The "Combine short spline blocks" function allows you to combine these
blocks such that the resulting block length is sufficient and does not reduce the path velocity.
The function is activated via the channel-specific machine data:
MD20488 $MC_SPLINE_MODE (setting for spline interpolation).
References:
Function Manual, Basic Functions; Continuous-Path Mode, Exact Stop, Look Ahead (B1),
Chapter: Combine short spline blocks
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
Special motion commands
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