Minimum Interval When Repeat~Ng The Same Interrupt Continuously - Mitsubishi Electric A1SI61 User Manual

3. INTERRUPT PROCESSING
MELSEC-A
3.3 Minimum Interval When Repeating the Same lnterrupt Continuously
When repeating the same interrupt continuously, set the interrupt interval
input pulse to a time greater than the total time until executing an interrupt
program by an interrupt signal and the execution time of an interrupt pro-
gram.lf it is set less than this total, the interrupt signal will be stored.
And then, the interrupt is executed after completing execution of an interrupt
program. However, even if several interrupt signals are input, an interrupt is
executed only once.
t l :
Time until executing an in-
n
terrupt program after in-
putting an interrupt
lnterrupt prog;am
12. Execution time of an inter-
rupt program
Interrupt input
I
I
I
I
I
(
(external switch)
L
This ~nterrupt signal is ignored.
3.4
lnterrupt Processing Priorities
If several interrupt factors occur during interrupt processing, the lowest input
number has the highest priority.
This is explained as Indicated below.
lnterrupt 12
lnterrupt detection
lnterrupt program
lnterrupt 15
Interrupt detection
lnterrupt program
-t--f
Y
lnterrupt
13
lnterrupt detection
lnterrupt program
lnterrupt 11
lnterrupt detection
lnterrupt program
Sequence program
\s
In t h ~ s example, the order of execution
IS:
Even if an interrupt factor occurs in the order of 15 and 13 while processing
interrupt 12, the interrupt program of 13 whose interrupt.number (pointer) is
lower has priority over 15. Therefore, after processing 12, 13 is executed.
And, w h ~ l e executing the 13 interrupt program, the I1 Interrupt factor occurs.
Therefore, after processing 13 before 15, the interrupt program of I1 will be
executed, after which 1 5 will be executed.