3.
.INTERRUPT PROCESSING
MELSEC-A
3.5
Creating an Interrupt Program
Create an interrupt program after a sequence program (after the FEND
~nstruction and before the END instruction). Enter the interrupt pointer I [ ] [ ]
at the head (the.left side of a bus) of an interrupt program.
And then, enter an IRET instruction at the end of the interrupt program.
o
F
I
Z
I
Sequence program
.
1. .
T<
to 1 1 0)
t
1
Program isexecuted
110
.
IRET
'
Interrupt program
Sample of interrupt program ladder
,
I t 0
lnterrupl
program
I
END
I
Program flow
POINTS
(1) When an interrupt program is executed by using an A1S161, it is
necessary to switch to the El state (interrupt enabled state) using an El
instruction.
(2)
The interrupt program that corresponds to interrupt input in the Dl state
is executed in the El state.
(3) The interrupt program that corresponds to interrupt input in STOP state
is executed in the El state after switching from the STOP state to the
RUN state.