Multiple Interrupt Function - Mitsubishi Electric MELSEC iQ-R Series User Manual

Multiple interrupt function

When a new interrupt triggered by another factor occurs during execution of an interrupt program, the running program will be
suspended if its priority is lower than that of the new interrupt. A program with higher priority is executed based on the set
priority whenever its execution condition is satisfied.
When the multiple interrupt function is enabled
[Priority]
I10: High
I0: Low
I10 interrupt program
I0 interrupt program
Main routine program
Time
(1) A high-priority interrupt is executed by interrupting a low-priority interrupt.
(2) Even if a high-priority interrupt occurs, it enters the waiting status until the interrupt in execution is completed.
Interrupt priority
If the interrupt priority of a program for which its execution condition has been satisfied is higher than that of the running
program, the programs are executed in accordance with their interrupt priority. If the interrupt priority of the new program is the
same or lower, it enters the waiting status until the running program finishes. The interrupt priorities 1 to 4 listed below cannot
be changed, whereas the interrupt priorities 5 to 8 can. ( Page 130 Interrupt priority setting)
Interrupt Interrupt factor (Interrupt pointer)
priority
High 1 High-speed interrupt by internal timer 1 (I49)

2 High-speed interrupt by internal timer 2 (I48)

3 Inter-module synchronous interrupt (I44), Multiple CPU
Low
synchronous interrupt (I45)
4 Interrupt by internal timer (I28 to I31), Fixed scan
execution type program
5 to 8 Interrupt from module (I0 to I15, I50 to I1023)
When not set (at default)
(1)
I10 interrupt program
I0 interrupt program
Main routine program
Execution sequence at simultaneous occurrence


I45  I44
I31  I30  I29  I28  Fixed scan execution type program
I0    I1023
Interrupt is being executed.
Interrupt stops.
(2)
Time
8 RUNNING A PROGRAM
interrupt occurs.
Program stops.
Program restarts.
Changeability
Unchangeable
(Fixed)
Changeable
129
8.7 Interrupt Program
8