Siemens SINUMERIK 840D Programming Manual page 321

4
03.96
09.01
If another value is assigned to parameter VARI, the
cycle is aborted and alarm
61002 "Machining type incorrectly programmed"
is output.
NUMT (number of thread starts)
With parameter NUMT you specify the number of
thread starts for a multiple thread. If you require a
single thread, either assign the value zero to the
parameter or omit it from the parameter list.
The thread starts are distributed uniformly around
the circumference of the turned part, the first thread
is defined in parameter NSP.
If a multiple-start thread with a non-uniform
distribution of threads around the circumference is to
be machined, the cycle must be called for every
thread start and the corresponding starting point
offset must be programmed.
_VRT (variable retraction path)
With SW 6.2 and higher, the retraction path can be
programmed on the basis of the initial thread
diameter in parameter _VRT.
When _VRT = 0 (parameter not programmed), the
retraction path is 1mm. The retraction path is always
measured in the programmed system of units inch or
metric.
© Siemens AG, 2002. All rights reserved
SINUMERIK 840D/840Di/810D Programming Guide Cycles (PGZ) – 11.02 Edition
4.8 Thread chaining – CYCLE98
0 degree mark
Start
1st thread
Start
2nd thread
4
Turning Cycles
Start
4th thread
NSP
Start
3rd thread
NUMTH = 4
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