Siemens SINUMERIK 840D sl Programming Manual page 257

Note
The DITS and DITE commands relate to setting data
SD42010 $SC_THREAD_RAMP_DISP[0,1], in which the programmed paths are written. If
no run-in/deceleration path is programmed before or in the first thread block, the
corresponding value is determined by the current value of SD42010.
References:
Function Manual, Basic Functions; Feedrates (V1)
Example
Program code
...
N40 G90 G0 Z100 X10 SOFT M3 S500
N50 G33 Z50 K5 SF=180 DITS=1 DITE=3
N60 G0 X20
Further information
If the run-in and/or run-out path is very short, the acceleration of the thread axis is higher than
the configured value. This causes an acceleration overload on the axis.
Alarm 22280 ("Programmed run-in path too short") is then issued for the thread run-in (with
the appropriate configuration in MD11411 $MN_ENABLE_ALARM_MASK). The alarm is
purely for information and has no effect on part program execution.
MD10710 $MN_PROG_SD_RESET_SAVE_TAB can be used to specify that the value written
by the part program is written to the corresponding setting data during RESET. The values
are, therefore, retained following power off/on.
Note
DITE acts at the end of the thread as a rounding clearance. This achieves a smooth change
in the axis movement.
When a block with the DITS and/or DITE command is loaded to the interpolator, the path
programmed under DITS is written to SD42010 $SC_THREAD_RAMP_DISP[0] and the path
programmed under DITE is written to SD42010 $SC_THREAD_RAMP_DISP[1].
The current dimensions setting (inch/metric) is applied to the programmed run-in/run-out
path.
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
9.10 Thread cutting with constant lead (G33)
Comment
; Start of smoothing with Z=53.
Motion commands
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