Siemens sinumerik 840d Programming Manual page 172

Special Motion Commands
5
5.5 Settable path reference, SPATH, UPATH (SW 4.3 and higher)
840D 840D
NCU 571 NCU 572
NCU 573
Programming example
The following program example shows the difference
between both types of motion control. Both times the
default setting FGROUP(X,Y,Z) is active.
N10 G1 X0 A0 F1000 SPATH
N20 POLY PO[X]=(10, 10) A10
or
N10 G1 X0 F1000 UPATH
N20 POLY PO[X]=(10, 10) A10
In block N20, path S of the FGROUP axes is
dependent on the square of curve parameter U.
Therefore, different positions arise for synchronized
axis A along the path of X, according to whether
SPATH or UPATH is active:
Control response at Power ON, mode change,
Reset, block search, REPOS
After Reset the G code defined via MD 20150:
GCODE_RESET_VALUES [44]
is active (45th G code group).
The basic setting value for the type of rounding is set
in MD 20150: GCODE_RESET_VALUES [9] (10th G
code group).
5-172
810D 840Di
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) − 04.00 Edition
SPATH:
A A
A(X)=X
10 10
10 X
Different geometry relationships between
axes with SPATH and UPATH
 Siemens AG 2000. All rights reserved
04.00
5
UPATH:
A(X)=SQRT(X)
10 X