Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 544

■EI
• This instruction clears the interrupt disabled state that has been set by the DI (Disabling interrupt programs) instruction, and
enables execution of interrupt programs with the interrupt pointer numbers permitted by the IMASK instruction. When the
IMASK instruction is not executed, I32 to I43 are disabled.
• For the operation of the EI instruction used with the DI (Disabling interrupt programs with specified priority or lower)
instruction, refer to the following.
Page 544 DI
In
A: Sequence program
B: Interrupt program
• The operation of the EI instruction in interrupt programs differs depending on the execution status of the DI (Disabling
interrupt programs with specified priority or lower) instruction before the EI instruction. The EI instruction in the interrupt
program after the execution of the DI (Disabling interrupt programs with specified priority or lower) instruction can be
executed.
When the EI instruction is executed in the interrupt program
after the DI (Disabling interrupt programs with specified priority
or lower) instruction was executed in the main routine program
A
SM400
(2)
B
M0
I50
A: Main routine program
B: Interrupt program
(1) The DI (Disabling interrupt programs with specified priority or lower)
instruction is executed.
(2) An interrupt has occurred.
(3) Execution of the interrupt program is enabled.
7 APPLICATION INSTRUCTIONS
542
7.3 Program Execution Control Instructions
A
DI
A
EI
FEND
B
INC D10
DI K7
(1)
Y0
EI
(3)
Even if an interrupt factor occurs between the DI and EI instructions, the
corresponding interrupt program will not be executed until the processing
between the DI and EI instructions completes.
When the EI instruction is executed in the interrupt program
without executing the DI (Disabling interrupt programs with
specified priority or lower) instruction in the main routine
program
A
SM400
INC
(2)
B
M0
I50
EI
A: Main routine program
B: Interrupt program
(1) The DI (Disabling interrupt programs with specified priority or lower)
instruction is not executed.
(2) An interrupt has occurred.
(3) Execution of the interrupt program is disabled. (No processing is
performed.)
D10
(1)
Y0
(3)