HEIDENHAIN TNC 407 (280 580) User Manual - Manual (Page 176)

TNC 425/TNC 415 B/TNC 407 6-2
6 Subprograms and Program Section Repeats
6 Subprograms and Program Section Repeats
Subprograms and program section repeats enable you to program a
machining sequence once and then run it as often as you desire.
Labels
Subprograms and program section repeats are marked by labels.
A label is identified by a number between 0 and 254. Each label (except
for label number 0) can be used only once with LABEL SET in a program.
LABEL 0 marks the end of a subprogram.
6.1 Subprograms
Principle
The program is executed up to the block in which a
subprogram in called via CALL LBL (
1 ).
The subprogram is then executed from beginning to
end (
2 ). The subprogram end is marked with LBL
0.
The main program is then resumed from the block
after the subprogram call (
3 ).
Operating limits
• A main program can hold up to 254 subpro-
grams.
• Subprograms can be called in any sequence and
as often as desired.
• A subprogram cannot call itself.
• Subprograms should be written at the end of the
main program (behind the block with M2 or
M30).
• If subprograms are located before the block with
M02 or M30, they will be executed at least once,
even if they are not called.
0 BEGIN PGM ...
CALL LBL 1
L Z + 100 M2
LBL 1
LBL 0
END PGM ...
1
2
3
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R
S
Fig. 6.1: Flow diagram for a subprogram run;
S = jump R = return jump