Siemens SINUMERIK 840D Programming Guide

5
04.00 Special Motion Commands
5.2 S
p
line inter
p
olation
5
840D
NCU 571
840D
NCU 572
NCU 573
FM-NC 810D 840Di
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Siemens AG 2000. All rights reserved
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA)
−
04.00 Edition
5-159
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.

Siemens SINUMERIK 840D Specifications

General

Series	SINUMERIK 840D
Axes	Up to 31
Channels	Up to 10
Operating System	Windows-based
Power Supply	24 V DC
Control Unit Type	CNC
Interface	Ethernet, PROFIBUS
Display	TFT color display
Interpolation	Spline
PLC	Integrated PLC
Data Storage	CompactFlash, USB