Settable Path Reference, Spath, Upath (Sw 4.3 And Higher) - Siemens sinumerik 840d Programming Manual

04.00
5

5.5 Settable path reference, SPATH, UPATH (SW 4.3 and higher)

840D 840D
NCU 571 NCU 572
NCU 573
5.5

Settable path reference, SPATH, UPATH (SW 4.3 and higher)

Programming
SPATH
UPATH
Introduction
During polynomial interpolation the user may require
two different relationships between the velocity-
determining FGROUP axes and the other path axes:
The latter are to be controlled
• either synchronized with the path of the FGROUP
axes
• or synchronized with the curve parameter.
Previously, only the first motion control variant was
implemented; now Software Version 4.3 and higher
offers a G code (SPATH, UPATH) for selecting and
programming the desired response.
Function
During polynomial interpolation – and here we are
referring to polynomial interpolation in the stricter sense
(POLY), all spline interpolation types (ASPLINE,
BSPLINE, CSPLINE) and linear interpolation with
compressor (COMPON, COMPCURV) – the positions
of all path axes i are preset by means of polynomials
p i (U). Curve parameter U moves from 0 to 1 within an
NC block, therefore it is standardized.
The axes to which the programmed path feed is to
relate can be selected from the path axes by means of
language command FGROUP. However, during
polynomial interpolation, an interpolation with constant
velocity on path S of these axes usually means a non
constant change of curve parameter U.
 Siemens AG 2000. All rights reserved
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) − 04.00 Edition
810D 840Di
Path reference for FGROUP axes is length of arc
The curve parameter is the path reference for FGROUP axes
Special Motion Commands
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