Siemens SINUMERIK 840D sl Programming Manual page 520

Work preparation
3.2 Subprogram technique
<number of
return jump levels>:
<return jump to the
beginning of the program>:
Note
For a subprogram return jump with a character string to specify the target block search, initially,
a search is always made for a jump marker in the calling program.
If a jump target is to be uniquely defined using a character string, it is not permissible that the
character string matches the name of a jump marker, as otherwise the subprogram return jump
would always be made to the jump marker and not to the character string (refer to example 2).
Supplementary conditions
When making a return jump through several program levels, the SAVE statements of the
individual program levels are evaluated.
If, for a return jump over several program levels, a modal subprogram is active and if in one of
the skipped programs the deselection command MCALL is programmed for the modal
subprogram, then the modal subprogram remains active.
NOTICE
Programming error
For a return jump across several program levels, it is the user's responsibility to ensure that
processing is continued with the necessary modal settings. This can be achieved, e.g. by
programming an appropriate main block.
520
The parameter specifies the number of program levels that should
be jumped through (return jumps) to search there for the target
block and continue processing the program.
Type: INT
Value: 1 The program is resumed at the "current pro‐
gram level -1" (just like RET without parame‐
ter).
2 The program is resumed at the "current pro‐
gram level -2", i.e. one level is skipped.
3 The program is resumed at the "current pro‐
gram level -3", i.e. two levels are skipped.
...
Range of 1 ... 15
values:
The parameter specifies, for a return jump into the main program,
whether the program should be continued at the start of the pro‐
gram in the active ISO dialect mode.
Type: BOOL
Value: 1 If the return jump is made into the main pro‐
gram and an ISO dialect mode is active there,
then the program branches to the beginning of
the program.
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming