Mitsubishi Electric MELSEC FX3U - 5. How to Specify Devices and Constants to Instructions; 5.1 Numeric Values Handled in PLCs (Octal, Decimal, Hexadecimal and Real Numbers)

156
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.12 Pointer [P and I]
Operations
3. Pointers for counter interrupt: 6 points
*1
→ For details on counter interrupt function, refer to Section 36.6.
The PLC executes an interrupt routine based on the comparison result obtained by the comparison set
instruction for high speed counter (DHSCS instruction).
Use these pointers for control requiring an interrupt routine based on the counting result from high speed
counters.
*1. This function is supported only in FX
3U/FX3UC PLCs.
*2. Cleared when the PLC mode switches from RUN to STOP.
Pointer No. Interrupt disabling flag Pointer No. Interrupt disabling flag
I010
M8059
*2
I040
M8059
*2
I020 I050
I030 I060
Step
0
I620
Pointer for
interrupt
Interrupt
routine
Interrupt is
enabled
Main program
is finished
Main
program
Interrupt at every 20 ms
Interrupt return
FNC 04
EI
FNC 06
FEND
FNC 03
IRET
END
"FEND" indicates the end of the main
program.
Make sure to describe an interrupt routine
after "FEND".
•
The PLC executes an interrupt routine at every
20 ms.
The PLC returns to main program by IRET
instruction.
•
Timer interrupt is enabled after EI instruction.
It is not necessary to program DI (disable
interrupt) instruction when no zone to disable
timer interrupt is needed.
•