Mitsubishi Q00JCPU User Manual page 153

3
SEQUENCE PROGRAM CONFIGURATION AND
EXECUTION CONDITIONS
(f) Execution interval of a fixed scan execution type program
Highest common factor of fixed scan execution interval* < Interrupt disabled time ••• Expression 1)
Highst common factor of scan execution interval
Program execution
operation
Interrupt enabled/disabled
status
Note that the execution interval of a fixed scan execution type program may
increase from the set interval depending on the time set for disabling interrupts by
the DI instruction (interrupt disabled time).
When the interrupt disabled time by the DI instruction is set to longer, use an
interrupt program by fixed scan interrupt (I28 to I31) instead of a fixed scan
execution type program.
* Means the highest common factor of fixed scan execution interval set to several fixed scan execution
type programs.
When the expression 1) is satisfied, the actual execution interval of a fixed scan
execution type program may increase from the set interval by the time shown in
the expression below.
Interrupt disabled time
The following shows an example of the increase in execution time of a fixed scan
execution type program.
Example
• Fixed scan execution interval •••10ms, 5ms, 1ms, 0.5ms
• Highest common factor of fixed scan execution interval ••• 0.5ms
• Interrupt disabled time (DI) •••5ms
• (Interrupt enabled time (EI) •••less than 0.5ms)
With the settings above, the expression 1) is 0.5ms < 5ms.
n scan
DI
Disabled
Interrupt disabled time = 5ms
Figure 3.49 Program execution operation and interrupt enabled status
Therefore, the execution time of a fixed scan execution type program whose
execution interval is set to 10ms increases 100ms (5
most.
3.3 Settings for Creation and Execution of Multiple Sequence Programs
Fixed scan execution interval set to the corresponding program
EI
DI
END
Ena-
Disabled
bled
Less than
0.5ms
Interrupt disabled time = 5ms
3.3.5 Fixed scan execution type program
n+1 scan
EI
END
Ena-
Disabled
bled
Less than
0.5ms
0.5 10 = 100) at the
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