Mitsubishi Electronics FX1S Interrupt Pointers, Additional applied instructions, Nested levels

FX Series Programmable Controllers Devices in Detail 4

4.6Interrupt Pointers

FX1S FX1N FX2N FX2NC

Device Mnemonic: I

Purpose: Interrupt program marker

Alias: Interrupt

High speed interrupt

I

Available forms: Label: appears on the left of the left hand bus bar when the program is viewed in ladder mode

(see ➀ in the example device usage diagram).

Devices numbered in: Special numbering system based on interrupt device used and input triggering method

Further uses: Input interrupts - see page 4-12

Timer interrupts - see page 4-12

Disabling interrupts - see page 4-13

Counter interrupts - see page 4-13

Example device usage:

FEND

I101

1

IRET

END

Additional applied instructions:

• Interrupts are made up of an interrupt device, an interrupt pointer and various usage of three, dedicated interrupt applied instructions;

-IRET function 03: interrupt return - see page 5-9

-EI function 04: enable interrupt - see page 5-9

-DI function 05: disable interrupt - see page 5-9

Nested levels:

•While an interrupt is processing all other interrupts are disabled. To achieve nested interrupts the EI-DI instruction must be programmed within an interrupt routine. Interrupts can be nested for two levels.

Pointer position:

•Interrupt pointers may only be used after an FEND instruction (first end instruction, function 06).

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