Omron CJ - REFERENCE MANUAL 10-2009 Reference Manual page 731

Multiple global subroutine regions (GSBN(751) to
GRET(752)) can be defined in interrupt task 0.
An SBS(091) or GSBS(750) instruction can be
written within a subroutine region (SBN(092) to
RET(093)) or global subroutine region (GSBN(751)
to GRET(752)) to "nest" subroutines. Subroutines
can be nested up to 16 levels.
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Cyclic or interrupt task
0.01
Interrupt task 0
Subroutine functions
divided by task.
Execution
condition ON
0.00
GSBS
n
B
GSBS
m
D
END
GSBN
n
A
GRET
GSBN
m
C
GRET
END
Interrupt task 0
GSBN 10 GSBN 11
to to
GSBS 11 GSBS 12
to to
GRET GRET
3. Instructions
B
Execution
condition ON
D
3
A
C
GSBN 12
to
GRET
693