Siemens SIMATIC S5 Manual page 150

STEP 5 Operations
Note
If interrupt processing is not required, you can reduce the PLC scan time.
Inhibit interrupt processing with the IA operation and switch off interval monitoring
when setting the operating system parameters with COM 115F.
Example
Disable interrupt processing in
a specific program section and
then enable it again.
1 Only one interrupt can be stored for each interrupt line.
3-54
STL
.
.
.
.
.
= Q 7.5
IA
A I 2.3
JU FB 254
NAME: SYNC
SYNC: KM000-0010
:
:
:
JU FB 3
.
.
.
RA
.
.
.
S5-115F Manual
Explanation
Disable interrupt.
Synchronization FB call for
servicing process/time interrupts
If an interrupt occurs, the
program section between the
operations IA and RA is scanned
without interruption.
Enable interrupt.
Interrupts that occurred in the
meantime are processed after
1
the "RA" operation.
EWA 4NEB 811 6149-02