Mitsubishi Electric MELSEC iQ-F FX5 - 11 INTERRUPT FUNCTION; 11.1 Multiple Interrupt Function; Interrupt priority

11 INTERRUPT FUNCTION
11.1 Multiple Interrupt Function
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11 INTERRUPT FUNCTION
This chapter describes the interrupt function.
11.1 Multiple Interrupt Function
When an interrupt occurs while an interrupt program triggered by another cause is running, stops the program if its priority is
lower than that of the new interrupt, and runs the higher-priority program whenever its execution condition is satisfied.
Precautions
A watchdog timer error may occur under the following conditions.
• When the interrupt frequency is high
• When the interrupt program execution time is long
When a watchdog timer error occurs, review the call frequency and execution time of the interrupt program.
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. (Page 74 The priority for the interrupt pointer
numbers and interrupt factors)
(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 executing interrupt is completed.
• When the multiple interruption function is enabled
I10 interrupt program
I0 interrupt program
Main routine program
Time
(1)
• When not set (at default)
During interruption execution
During interruption stop
I10 interrupt program
I0 interrupt program
Main routine program
Time
(2)
[Priority]
• I10: High
• I0: Low
Interruption occurred
Program stops
Program restarts