Siemens SIMATIC S5 Manual page 197

General Notes
User program can be interrupted
at:
When using the interrupt OBS the
scratchpad flags must be saved and
loaded again before exiting the
interrupt OB
Calling handling blocks in interrupt
branches
Start-up types
Cold restart
beginning of the cy;~ic
processing
Automatic warm restart
beginning of the cyclic
processing
Manual warm restart
Saving scratchpad flags and
operating system data
in OB21 and OB22
1 ) If this is necessary, you must ensure that FB164 is not interrupted in the cyclic program.
2) FB164 should be run through once for each axis before the first operation job is sent, to allow
the binary identifiers in the DB for each specific axis to be updated.
3) See S5-150U
4) See note on following page
6 - 4
115U 135U
Block
Command
boundaries boundaries
or
command
boundaries
to to
RS 60
to
not not
)
permitted ' permitted if
interrupts
are at
ri 1)
n
bou da es
at start of at start of OB 1
OB 1
at start of at interrupt point
OB 1
OB 21, at interrupt point
not not
permitted permitted
save FYB200 to FY255 4)
to
150U 155U
Block
Block
boundaries boundaries
or
command
boundaries
work with
to
permitted see
not
not
permitted in permitted
in OB21
and OB22
see note 3)