Settable Path Reference (Spath, Upath) - Siemens Sinumerik 840D sl Programming Manual

Special Motion Commands

4.6 Settable path reference (SPATH, UPATH)

4.6 Settable path reference (SPATH, UPATH)
Function
During polynomial interpolation, the user may require two different relationships between the
velocity determining FGROUP axes and the other path axes: The latter should either be
controlled, synchronized to the path S or synchronized to the curve parameter U of the
FGROUP axes.
Both types of path interpolation are used in different applications and can be set/switched
over using the two modal language commands SPATH and UPATH contained in the 45th G
code group.
Syntax
SPATH
UPATH
Meaning
SPATH:
UPATH:
Note
UPATH and SPATH also define the interrelationship of the F word polynomial (FPOLY, FCUB,
FLIN) with path motion.
General conditions
The path reference set is of no importance:
• for linear and circular interpolation
• in thread blocks
• if all path axes are contained in FGROUP.
Examples
Example 1:
The following example shows a square with 20 mm side lengths and corners rounded-off with
G643. The maximum deviations from the precise contour are defined for each axis using the
axis-specific machine data MD33100 $MA_COMPRESS_POS_TOL[<n>].
268
Path reference for FGROUP axes is arc length
Path reference for FGROUP axes is curve parameter
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
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