Recovery From Interrupt Programs (Iret) - Mitsubishi MELSEC QCPU Programming Manual

6 BASIC INSTRUCTIONS

6.6.2 Recovery from interrupt programs (IRET)

Internal Devices
Set
(System, User)
Data
Bit Word
[Instruction Symbol] [Execution Condition]
I
IRET
[Functions]
(1) Indicates the completion of interrupt program processing.
(2) Returns to sequence program processing following the execution of the IRET instruction.
[Operation Errors]
(1) In the following cases an operation error occurs, the error flag (SM0) turns ON, and an error
code is stored at SD0.
• There is no pointer corresponding to the interrupt number.
• The IRET instruction has been issued prior to the execution of the interrupt program.
• An END, FEND, GOEND, or STOP instruction as been executed after the generation of an
interrupt and prior to the execution of the IRET instruction.
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Usable Devices
MELSECNET/10(H)
File Direct J \
Register
Bit Word
QCPU
PLC CPU
Process CPU
Basic
High Performance
Special
Index
Function
Register
Module
Zn
U \G
MELSEC-Q/QnA
QnA Q4AR
Constant
Other
K, H
IRET
(Error code: 4220)
(Error code: 4223)
(Error code: 4221)
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