FX Series Programmable Controllers Devices in Detail 4
4-11
4.6 Interrupt Pointers
Device Mnemonic:
I
Purpose:
Interrupt pro
ram marker
Alias:
Interrupt
Hi
h speed interrupt
I
Available forms:
Label: appears on the left of the left hand bus bar when the pro
ram is
viewed in ladder mode
(see
¿
in the example device usa
e dia
ram).
Devices numbered in:
Special numberin
s
stem based on interrupt device used and input
tri
erin
method
Further uses:
Input interrupts - see pa
e 4-12
Timer interrupts - see pa
e 4-12
Disablin
interrupts - see pa
e 4-13
Counter interrupts - see pa
e 4-13
Example device usage:
Additional applied instructions:
• Interrupts are made up of an interrupt device, an interrupt pointer and various usa
e of
three, dedicated interrupt applied instructions;
- IRET function 03: interrupt return - see pa
e 5-9
- EI function 04: enable interrupt - see pa
e 5-9
- DI function 05: disable interrupt - see pa
e 5-9
Nested levels:
• While an interrupt is processin
all other interrupts are disabled. To achieve nested inter-
rupts the EI-DI instruction must be pro
rammed within an interrupt routine.
Interrupts can be nested for two levels.
Pointer position:
• Interrupt pointers ma
onl
be used after an FEND instruction (first end instruction, func-
tion 06).
