Siemens SINUMERIK 840D sl Function Manual page 194

B1: Continuous-path mode, Exact stop, Look Ahead
4.3 Continuous-path mode
Value E or Z
3
4
Profile for limit velocity
The use of a velocity profile for rounding in compliance with defined tolerances is controlled
via the hundreds position in MD20480:
Value
< 100:
≥100:
Note
MD28530 $MC_MM_PATH_VELO_SEGMENTS (number of memory elements for limiting the
path velocity)
Supplementary conditions
Restriction for protection zones with active radius compensation and tool orientation:
Although tool radius compensation is applied for a tool orientation, which is not perpendicular
to one of the three datum planes of the basic coordinate system, the protection zones are not
rotated onto the corresponding plane.
For G643 the following must apply:
MD28530 $MC_MM_PATH_VELO_SEGMENTS > 0 (number of memory elements for limiting
the path velocity)
If this condition is met, then it must be applicable for all axes:
194
Meaning
Geometry axes:
Rounding by maintaining the contour tolerance and the orientation tolerance:
SD42465 $SC_SMOOTH_CONTUR_TOL
SD42466 $SC_SMOOTH_ORI_TOL
Remaining axes:
Rounding by maintaining the maximum permitted path deviation:
MD33100 $MA_COMPRESS_POS_TOL
All axes:
The rounding length programmed with ADIS or with ADISPOS is used (as in case of
G641).
Any axis-specific tolerance or contour and orientation tolerance specifications are
ignored.
Meaning
A profile of the limit velocity is calculated within the rounding area, based on the defined
maximum values for acceleration and jerk on the participating axes or path.
This can lead to an increase in the path velocity in the rounding area and therefore to the
acceleration of the participating axes.
A profile of the limit velocity is not calculated for rounding blocks with G641/G642. A
constant velocity limit is specified instead.
This prevents the participating axes being accelerated into the rounding area during
rounding with G641/G642. However, in certain cases, this setting can cause the rounding
blocks to be traversed too slowly, especially in large rounding areas.
1xx: No velocity profile for G641
2xx: No velocity profile for G642
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions