Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 549

• When the DI (Disabling interrupt programs) instruction, DI (Disabling interrupt programs with specified priority or lower)
instruction, and EI instruction are executed, the interrupt disabled sections will be as follows.
• When another DI (Disabling interrupt programs with specified priority or lower) instruction with a wider priority range is executed during execution of the DI
(Disabling interrupt programs with specified priority or lower) instruction
(1)
A
EI DI K3
t
A: Scan execution type program
(1) Interrupt enabled section for all priorities
(2) Interrupt disabled section for priority 3 to 8 (Interrupt enabled section for priority 1 and 2)
(3) Interrupt disabled section for priority 2 to 8 (Interrupt enabled section for priority 1)
• When another DI (Disabling interrupt programs with specified priority or lower) instruction with a narrower priority range is executed during execution of the DI
(Disabling interrupt programs with specified priority or lower) instruction
(1)
A
EI DI K2
t
A: Scan execution type program
(1) Interrupt enabled section for all priorities
(2) Interrupt disabled section for priority 2 to 8 (Interrupt enabled section for priority 1)
(3) The priority of the disabled interrupt remains unchanged because the interrupt with priority 2 or lower is already disabled.
• When the DI (Disabling interrupt programs with specified priority or lower) instruction is executed in the interrupt program
(1)
B
A
EI DI K3
t
A: Scan execution type program
B: Interrupt program
(1) Interrupt enabled section for all priorities
(2) Interrupt disabled section for priority 3 to 8 (Interrupt enabled section for priority 1 and 2)
(3) Interrupt disabled section for priority 2 to 8 (Interrupt enabled section for priority 1)
• When only the DI (Disabling interrupt programs) instruction is executed
(1)
A
EI DI
t
A: Scan execution type program
(1) Interrupt enabled section for all priorities
(2) Interrupt disabled section for priority 1 to 8 (Interrupt disabled section for all priorities)
(3) Executing the EI instruction only once enables interrupts with all priorities.
(2) (3)
DI K2 EI
(2)
DI K3 EI
(3)
(2) (3) (2)
DI K2 EI
(2)
DI DI
(2) (1)
EI
(1)
EI
(1)
IRET
EI
(1)
EI
(3)
7 APPLICATION INSTRUCTIONS
7.3 Program Execution Control Instructions
7
547