HEIDENHAIN TNC 360 ISO Programming - Manual (Page 125)

6 Subprograms and Program Section Repeats
TNC 360 6-2
Fig. 6.1: Flow diagram for a subprogram;
S = jump, R = return jump
R
S
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1
2
3
N1 % ... *
L1, 0 *
Z + 100 M2 *
G98 L1 *
G98 L0 *
N9999 % ... *
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 wish.
Labels
Subprograms and program section repeats are marked by labels.
A label carries a number from 0 to 254. Each label number (except 0) can
only appear once in a program. Labels are assigned with the command
G98.
LABEL 0 marks the end of a subprogram.
6.1 Subprograms
Principle
The (main) program is executed up to the block in
which the subprogram is called with Ln,0 (
1 ).
Then the subprogram is executed from beginning to
end (G98 L0) (
2 ).
Finally, the main program is resumed from the
block after the subprogram call (
3
).
Operating limits
• One main program can contain up to 254
subprograms.
• Subprograms can be called in any sequence and
as often as desired.
• A subprogram cannot call itself.
• Subprograms should be located at the end of the
main program (after the block with M2 or M30).
• If subprograms are located in the program before
the block with M02 or M30, they will be execut-
ed at least once even without being called.