Siemens sinumerik 840d Programming Manual page 159

04.00
5
840D 840D
NCU 571 NCU 572
NCU 573
Settings for splines
The G codes ASPLINE, BSPLINE and CSPLINE link
block endpoints with splines.
For this purpose, a series of blocks (endpoints) must
be simultaneously calculated.
The buffer size for calculations is 10 blocks as
standard.
Not all block information is a spline endpoint.
However, the control requires a certain number of
spline endpoint blocks from 10 blocks.
They are as follows for:
A spline: At least 4 blocks out of every 10 must be spline blocks. These do not include comment
blocks and parameter calculations.
B spline: At least 6 blocks out of every 10 must be spline blocks. These do not include comment
blocks and parameter calculations.
C spline: From each 10 blocks at least the contents of machine data
$MC_CUBIC_SPLINE_BLOCKS+1 must be spline blocks (also in standard case 9)
The number of points must be entered in machine data
$MC_CUBIC_SPLINE_BLOCKS (standard value 8) which are used for calculating the
spline segment.
An alarm is output if the tolerated value is exceeded
and likewise when one of the axes involved in the
spline is programmed as a positioning axis.
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SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) − 04.00 Edition
FM-NC 810D 840Di
Special Motion Commands
5.2 Spline interpolation
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