Mitsubishi Electric MELSEC FX3U Programming Manual page 157

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Operations
Pointer for
interrupt
I001
Pointer for
interrupt
I101
2. Pointers for timer interrupt: 3 points
The PLC executes an interrupt routine program at every specified interrupt cycle time (10 to 99 ms).
Use these pointers for control requiring cyclic processing regardless of the operation cycle of the PLC.
Input No.
I6
I7
I8
*1. This function is supported only in FX
*2. Cleared when the PLC mode switches from RUN to STOP.
Caution
It is recommended to set the timer interrupt time to 10 ms or more. When the timer interrupt time is set to 9
ms or less, the timer interrupt processing may not be executed at an accurate cycle in the following cases:
• When the processing time of the interrupt program is long
• When an instruction requiring long processing time is used in the main program
FNC 04
EI
Interrupt enabled
range
FNC 06
FEND
Rising edge of X000 is detected
Interrupt routine [1]
FNC 03
IRET
Rising edge of X001 is detected
Interrupt routine [2]
FNC 03
IRET
END
→ For details on timer interrupt function, refer to Section 36.5.
Interrupt cycle (ms)
An integer in the range from 10 to 99 is put in "
pointer name.
Ex: I610 = Timer interrupt at every 10 ms
/FX
3U
•
Interrupt is usually disabled in the PLC.
If interrupt is enabled by EI instruction, when
X000 or X001 turns ON while a program is
scanned, the PLC executes the interrupt
routine [1] or [2], and then returns to the main
program by IRET instruction.
•
Make sure to program a pointer for interrupt
(I***) as a label after FEND instruction.
" portion of the
PLCs.
3UC
4 Devices in Detail
4.12 Pointer [P and I]
Interrupt disabling flag
*1
M8056
*1
M8057
*1
M8058
155
1
2
3
4
5
6
7
8
9
10