Siemens SINUMERIK 840Di Function Manual page 170

Detailed Description
2.3 Continuous-path mode
Setting parameters for path smoothing
The user can define the following parameters to set the path smoothing:
• Use of MD20460 to increase machining time
• Use of MD32440 to input the resonance frequencies of the participating axes
• Use of MD20462 to take into account the programmed feedrate for smoothing
MD20460
A percentage value corresponding to the permissible extension must be specified in machine
data:
MD20460 LOOKAH_SMOOTH_FACTOR.
The percentage value defines how much longer a machining step without accelerations may
be than the corresponding step when performing the accelerations/decelerations.
This would be a "worst-case" value, if all accelerations within the part program, except the
initial approach motion, were smoothed.
The actual extension will always be smaller, and may even be 0, if the criterion is not met by
any of the accelerations.
Values between 50 and 100% may also be entered without significantly increasing the
machining time.
MD20462
Machine data:
MD20462 LOOKAH_SMOOTH_WITH_FEED
defines that the programmed feedrate will also be taken into account in the rounding.
If the MD is set to 1 (default), the smoothing factor is observed with particular precision if the
override is set to 100%.
2-22
If the velocity is not accelerated, it will take longer to process this part program (see
example).
Only accelerations in velocity, which clearly excite machine resonances, should be
removed
Continuous-Path Mode, Exact Stop, LookAhead (B1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0