Siemens SINUMERIK 840D Programming Manual page 256

Turning Cycles
4
4.8 Thread chaining – CYCLE98
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.
4-256
Start
1st thread
Start
2nd thread
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide, Cycles (PGZ) - 04.00 Edition
03.96
4
0 degree mark
Start
4th thread
NSP
Start
3rd thread
NUMTH = 4
 Siemens AG 2000 All rights reserved.