Siemens SIMATIC S5 IP 281 Equipment Manual page 79

R 11/92
4 Interrupt Processing
What Is Interrupt Processing?
4.1
Interrupt processing takes place when a signal external to the processor (CPU, central processing
unit of the PLC) interrupts the running program and triggers a separate program (the interrupt pro-
gram).
Interrupt processing is involved when such an interrupt signal is acquired via interrupt lines and
fed to the central processing unit.
via input byte 160.
Only interrupt processing
availabe on this module.
The interrupt program acknowledges the queued interrupt and evaluates it by reading and storing
current actual values, for example, or by generating an immediate reaction on a digital output
module. After the interrupt program is processed, processing of the interrupted program is contin-
ued at the point at which it was interrupted.
Interrupt processing is used to achieve fast reactions to changes in signal status.
Process interrupt processing is involved when acquisition is
can be triggered on the 1P 281. Process interrupt processing is
Interrupt Processing
not
4 – 1