Program Execution Control Instruction - Mitsubishi Electric MELSEC iQ-F FX5 Programming Manual

8.3

Program Execution Control Instruction

Disabling/enabling interrupt programs
DI, EI
Interrupts are usually disabled in CPU module. These instructions enable interrupts in CPU module (EI instruction) or disable
interrupts again (DI instruction).
• DI: Disables the execution of the interrupt program.
• EI: Releases the execution disabled state of interrupt programs.
Ladder diagram
FBD/LD
EN ENO
Processing details
■DI
• This instruction disables the execution of the interrupt program until the EI instruction is executed, even if the interrupt
cause occurs.
• When the power is turned on or the CPU module is reset, the state in which the DI instruction is executed is applied.
• For the operation of the DI instruction (DI instruction without an argument) when using the interrupt disable instruction with
a specified priority or lower (DI instruction with an argument), refer to Page 387 Disabling the interrupt program with
specified priority or lower.
■EI
• This instruction releases the execution disabled state of interrupt programs when the DI instruction is executed, and
enables the execution of the interrupt program with the interrupt pointer number enabled by the IMASK instruction.
• For the operation of the EI instruction when using the interrupt disable instruction with a specified priority or lower (DI
instruction with an argument), refer to Page 387 Disabling the interrupt program with specified priority or lower.
A
A
In
B
A: Sequence program
B: Interrupt Program
Even though an interrupt occurs between
the DI and EI instructions, the execution of
DI
the interrupt is held until the processing
between the instructions ends.
EI
FEND
Structured text
ENO:=DI(EN);
ENO:=EI(EN);
8 APPLICATION INSTRUCTION
8.3 Program Execution Control Instruction
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