Siemens SINUMERIK 840D sl Function Manual page 193

Parameterization
Maximum path deviation
The maximum path deviation permitted with G642/G643 is set for each axis in the machine
data:
MD33100 $MA_COMPRESS_POS_TOL
Contour tolerance and orientation tolerance
The contour tolerance and orientation tolerance are set in the channel-specific setting data:
SD42465 $SC_SMOOTH_CONTUR_TOL (maximum contour deviation)
SD42466 $SC_SMOOTH_ORI_TOL (maximum angular deviation of the tool orientation)
The settings data can be programmed in the NC program and can in this way be specified
differently for each block transition.
Note
The setting data SD42466 $SC_SMOOTH_ORI_TOL is effective only in active orientation
transformation.
Rounding behavior
Rounding behavior with G642 and G643 is configured via the machine data:
MD20480 $MC_SMOOTHING_MODE (rounding behavior with G64x)
The units positions (E) define the behavior for G643, the tens positions (Z) the behavior for
G642:
Value E or Z
0
1
2
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Meaning
All axes:
Rounding by maintaining the maximum permitted path deviation:
MD33100 $MA_COMPRESS_POS_TOL
Geometry axes:
Rounding by maintaining the contour tolerance:
SD42465 $SC_SMOOTH_CONTUR_TOL
Remaining axes:
Rounding by maintaining the maximum permitted path deviation:
MD33100 $MA_COMPRESS_POS_TOL
Geometry axes:
Rounding by maintaining the orientation tolerance:
SD42466 $SC_SMOOTH_ORI_TOL
Remaining axes:
Rounding by maintaining the maximum permitted path deviation:
MD33100 $MA_COMPRESS_POS_TOL
B1: Continuous-path mode, Exact stop, Look Ahead
4.3 Continuous-path mode
193