Siemens SINUMERIK 828D Function Manual page 195

Activation/Deactivation
The function can be switched on or off independently for every dynamic response mode (see "Dynamic response
mode for path interpolation [Page 191]"):
MD20606 $MC_PREPDYN_SMOOTHING_ON[<n>] = <value>
Index <n> Dynamic response mode
0 Standard dynamic response
settings (DYNNORM)
1 Positioning mode, tapping
(DYNPOS)
2 Roughing (DYNROUGH)
3 Finishing (DYNSEMIFIN)
4 Smooth-finishing (DYNFINISH)
Note
Due to the additional storage requirements, the function should only be activated in the
relevant processing channels.
Parameter assignment
Change in the contour sampling factor
The secant error which occurs during the interpolation of curved contours is dependent on the following factors:
• Curvature
• Interpolation cycle (display in the MD10071 $MN_IPO_CYCLE_TIME)
• Velocity with which the relevant contour is traversed
The max. possible secant error is defined for each axis in the machine data:
MD33100 $MA_COMPRESS_POS_TOL (maximum tolerance with compression)
If the set interpolation cycle is not sufficiently small, the max. path velocity may be reduced in the case of
contours with greater curvature. This is necessary for ensuring that the surface of the workpiece is also produced
with an adequate degree of precision in this case.
By changing the contour sampling factor, the time interval with which a curved contour is sampled in the
interpolator (contour sampling time) can be set at variance with the interpolation cycle. A contour sampling time
which is shorter than the interpolation cycle can prevent a reduction in path velocity in the case of contours with
greater curvature.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
B1: Continuous­path Mode, Exact Stop, LookAhead
Free-form surface mode: Basic
<value>
functions
0 off
1 on
0 off
1 on
0 off
1 on
0 off
1 on
0 off
1 on
3.4 Dynamic adaptations
195