Siemens SIMATIC S7 - Page 332

Program instructions
7.10 Interrupt
S7-200 SMART
332 System Manual, V2.3, 07/2017, A5E03822230-AF
Example 1: Input signal edge detector interrupt
LAD
STL
MAIN
Network 1
On the first scan:
1. Define interrupt routine
INT_0 to be a falling-edge
interrupt for I0.0.
2. Globally enable interrupts.
Network 1
LD SM0.1
ATCH INT_0, 1
ENI
Network 2
If an I/O error is detected, disa-
ble the falling-edge interrupt for
I0.0.
(This network is optional.)
Network 2
LD SM5.0
DTCH 1
Network 3
When M5.0 is on, disable all
interrupts. When disabled,
attached interrupt events will be
queued, but the corresponding
interrupt routines will not be
executed until interrupts are re-
enabled with the ENI instruc-
tion.
Network 3
LD M5.0
DISI
INT 0
Network 1
I0.0 falling-edge interrupt rou-
tine: Conditional return based
on an I/O error.
Network 1
LD SM5.0
CRETI