HEIDENHAIN TNC 320 (340 55x-05) - Manual (Page 220)

220 Programming: Subprograms and Program Section Repeats
7.
5 Nesting
Repeating a subprogram
Example NC blocks
Program execution
1 Main program SUBPGREP is executed up to block 11.
2 Subprogram 2 is called and executed.
3 Program section between block 10 and block 12 is repeated twice.
Subprogram 2 is repeated twice.
4 Main program SUBPGREP is executed from block 13 to block 19.
End of program.
0 BEGIN PGM SUBPGREP MM
...
10 LBL 1 Beginning of program section repeat 1
11 CALL LBL 2 Subprogram call
12 CALL LBL 1 REP 2 The program section between LBL 1 (block 10)
... and this block is repeated twice
19 L Z+100 R0 FMAX M2 Last block of the main program with M2
20 LBL 2 Beginning of subprogram
...
28 LBL 0 End of subprogram
29 END PGM SUBPGREP MM