Siemens SINUMERIK 840D sl Function Manual page 176

Detailed description
2.3 Continuous -path mode
Selection and deselection of rounding blocks
Program code G641 can be inserted in any NC part program block to modally select
rounding according to a path criterion. Before or on selection, the path criteria
ADIS/ADISPOS must be specified.
Continuouspath mode G641 can be
• Interrupted non-modally by selecting exact stop G09
• Deselected by selecting exact stop G60
• Deselected by selecting velocity drop G64
Rounding with axial tolerances
In addition to rounding using the command G641, rounding with axial tolerances enabled
modally using G642 is possible.
In this case, instead of rounding being performed within a defined ADIS range, the axial
tolerances defined with the following machine data are used.
MD33100 $MA_COMPRESS_POS_TOL (maximum tolerance with compression).
The mode of operation is otherwise identical to G641.
References:
/PG/Programming Manual Fundamentals
Extensions
G643 is not used to generate a separate rounding block, but axisspecific blockinternal
rounding movements are inserted.
The expansions described below refine the response with G642 and G643 and "rounding
with contour tolerance" is introduced.
When rounding with G642 and G643, the maximum permissible deviations of each axis are
normally specified.
Rounding with G642 and G643 can be configured with the following machine data such that
instead of the axis-specific tolerances, a contour tolerance and an orientation tolerance can
be specified.
MD20480 $MC_SMOOTHING_MODE (rounding behavior with G64x)
In this case, the tolerance of the contour and of the orientation is set using two independent
setting data, which can be programmed in the NC program. This means that different setting
data can be specified for each block transition.
Contour tolerance
A contour tolerance is specified using the setting data:
SD42465 $SC_SMOOTH_CONTUR_TOL (maximum contour tolerance when rounding)
This setting data defines the maximum rounding tolerance for the contour.
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Basic logic functions: Continuouspath Mode, Exact Stop, LookAhead (B1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0