Tolerance And Compression Of G0 Blocks - Siemens SINUMERIK 840D sl Function Manual

Supplementary conditions
Programming
The tolerances programmed with CTOL, OTOL, and ATOL also affect functions that indirectly
depend on these tolerances:
● Limiting the chord error in the setpoint value calculation
● The basic functions of the free-form surface mode
The following rounding functions are not affected by the programming of CTOL, OTOL, and
ATOL:
● Rounding orientation with OSD
OSD does not use a tolerance, it uses a distance from the block transition.
● Rounding with G644
G644 is not used for processing, it is used for optimizing tool changes and other movements
without machining.
● Rounding with G645
G645 virtually always behaves like G642 and, thus, uses the programmed tolerances. The
tolerance value from machine data MD33120 $MA_PATH_TRANS_POS_TOL is only used
in uniformly tangential block transitions with a jump in curvature, e.g. a tangential circle/
straight line transition. The rounding path at these points may also be located outside the
programmed contour, where many applications are less tolerant. Furthermore, it generally
takes a small, fixed tolerance to compensate for the sort of changes in curvature which
need not concern the NC programmer.
4.7

Tolerance and compression of G0 blocks

Function
The function "Tolerance and compression of rapid traverse blocks (G00)" allows rapid traverse
motion to be traversed faster.
It consists of the components:
1. Parameterization / programming of a tolerance factor for rapid traverse movements
Using this factor, the tolerances for G0 motion can be set differently to the workpiece
machining tolerances.
2. Compressing G0 blocks
If the compression of G0 blocks is active while NC block compression is active, not only
traversing blocks with programmed feedrate (G01) but also traversing blocks with G0 (rapid
traverse) are compressed.
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
B1: Continuous-path mode, Exact stop, Look Ahead
4.7 Tolerance and compression of G0 blocks
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