Mitsubishi Electronics FX3G User Manual
233
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
8 Program Flow – FNC 00 to FNC 09
8.4 FNC 03 – IRET / Interrupt Return
1
Introdu
ction
2
Ov
ervi
ew
ew
3
Instruction
Li
st
4
D
evices
in Det
ai
l
5
Specifi
ed the
De
vice
&
C
onst
ant
ant
6
Bef
ore
ore
Pr
og
ra
mmi
ng
ng
7
Bas
ic
ic
Instruction
8
FN
C00-FN
C00-FN
C0
9
Program Fl
ow
9
FNC
10-FN
C19
Mov
e & Com
e & Com
pare
10
FNC
20-FNC
29
Arith. & Lo
gi
c
Operati
on
8.4
FNC 03 – IRET / Interrupt Return
Outline
This instruction returns the program execution from an interrupt routine to the main program.
1. Instruction format
2. Set data
3. Applicable devices
Explanation of function and operation
When an interrupt (input, timer or counter) is generated while the main program is executed, the program execution
jumps to an interrupt (I) routine.
IRET instruction returns the program execution to the main routine.
The table below shows three types of jump to an interrupt routine.
jumps to an interrupt (I) routine.
IRET instruction returns the program execution to the main routine.
The table below shows three types of jump to an interrupt routine.
1. Types of interrupt function
*1.
This function is supported only in FX
3U
/FX
3UC
PLCs.
→ For the interrupt function, refer to Chapter 36.
Operand type
Description
Data type
–
There is no set data.
–
Oper-
and
Type
Bit Devices
Word Devices
Others
System User
Digit Specification
System User
Special
Unit
Index
Con-
stant
stant
Real
Number
Charac-
ter String
Pointer
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
V Z Modify K H
E
" "
P
–
There are no applicable devices.
Function
Interrupt No.
Description
Reference
Input interrupt
I00* to I50*
Executes the interrupt processing when an input (X) signal turns ON or
OFF.
OFF.
Section 36.3 and
Section 36.4
Timer interrupt
I6** to I8**
Executes the interrupt processing at a specified time interval (constant
cycle).
cycle).
Section 36.5
Counter interrupt
*1
I010 to I060
Executes the interrupt processing when a high-speed counter reaches
it’s set value.
it’s set value.
Section 36.6
FNC 03
IRET
IRET
Mnemonic
Operation Condition
Continuous
Operation
Independent Inst.
1 step
This instruction is the independent type, and
does not require drive contact.