Siemens Simatic S7-200 System Manual page 310

Instruction Set
Interrupt Examples
Figure 10-57 shows an example of the Interrupt Routine instructions.
Network 1
SM0.1
Network 2
SM5.0
Network 3
M5.0
.
.
.
Network 50
.
.
.
Network 60
4
INT
.
.
.
Network 65
SM5.0
Network 66
Figure 10-57
10-122
LAD
On the first scan:
ATCH
Define interrupt routine 4
EN
to be a rising edge
interrupt routine for I0.0.
4 INT
0 EVENT
Globally enable
ENI
interrupts.
DTCH
If an I/O error is detected,
disable the rising edge
EN
interrupt for I0.0.
(This rung is optional.)
0 EVENT
Disable all interrupts
DISI
when M5.0 is on.
End of main ladder.
END
I/0 rising edge interrupt
subroutine.
Conditional return based
RETI
on I/O error
End of I0.0 rising edge
RETI
interrupt routine.
Example of Interrupt Instructions
Network 1
LD SM0.1
ATCH 4, 0
ENI
Network 2
LD SM5.0
DTCH 0
Network 3
LD M5.0
DISI
.
.
.
Network 50
MEND
.
.
.
Network 60
INT 4
.
.
.
Network 65
LD SM5.0
CRETI
Network 66
RETI
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02
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