Mitsubishi Electric FX3G SERIES Programming Manual page 815

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
3. Basic program (programming procedure)
Step
0
When interrupt is
Interrupt
given at every 20 ms
pointer
I620
4. Number and operation of (three) timer interrupt pointers
I
Timer time: 10 to 99 (ms)
Timer interrupt pointer (6, 7 or 8)
An interrupt routine program is executed at every specified interrupt cycle time (10 to 99 ms). Use the type of interrupt
in control requiring cyclic interrupt processing regardless of the operating cycle of a PLC.
Input number
I6
I7
I8
*1. Cleared when the PLC mode is changed from RUN to STOP.
Caution
If the timer interrupt time is set to 9ms or less, the timer interrupt processing may not be executed in an accurate cycle
in the following cases. Therefore, using a time that is over 10 ms is recommended.
• When the interrupt program processing time is long
• When the main program contains an applied instruction which processing time is long
5. Cautions
• Each pointer number (I6, I7 or I8) can only be used once.
• When M8056 to M8058 is set to ON in a program, a corresponding timer interrupt is disabled.
FNC 04
Interrupts are
EI
enabled
Main
program
End of
FNC 06
main program
FEND
Interrupt
routine
FNC 03
Interrupt return
IRET
END
Interrupt cycle (ms)
An integer ranging from 10 to 99 is put in "
Example: "I610" indicates a timer interrupt at every 10 ms.
36 Interrupt Function and Pulse Catch Function
36.5 Timer Interrupt (Interrupt in Constant Cycle)
Main program
Timer interrupts are enabled after the EI instruction.
It is not necessary to program DI (disable
interrupt) if there is no zone where input
interrupts should be disabled.
The FEND instruction indicates the end of the main
program.
Make sure to describe an interrupt routine after
the FEND instruction.
Interrupt subroutine
The interrupt routine is executed at every 20 ms.
Create a program to be executed as interrupt.
The IRET instruction returns the program execution
to the main program.
" in the pointer name.
Interrupt disable Flag
*1
M8056
*1
M8057
*1
M8058
813
31
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35
36
37
38
A
B