Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual page 59

■If another interrupt occurs while the fixed scan execution type program is being executed
If an interrupt program (including an interrupt which triggers the event execution type program) is triggered while the fixed
scan execution type program is being executed, the program operates in accordance with the interrupt priority. ( Page 81
Multiple interrupt function)
Processing when the fixed scan execution type program starts
The same processing as when the interrupt program starts. ( Page 78 Processing at interrupt program startup)
Fixed scan execution mode
For fixed scan interrupts (I28 to I31, I48, I49) triggered by the fixed scan execution type program or the internal timer of the
CPU module, this mode specifies the program execution operation that is performed when more than one interrupt occurs
( Page 68 Operation upon occurrence of an interrupt factor) However, an execution cause which occurs while the
interrupt is disabled by the DI instruction is excluded from the fixed scan execution mode target.
■Operation in the fixed scan execution mode
This section describes the operation which can be performed in the fixed scan execution mode.
• Execution Count Takes Priority
The program is executed for all the pending number of executions so that it can be executed the same number of times as
execution causes.
Cycle interval of TEISYU
"TEISYU"
(Fixed scan execution type program)
(1) The program is executed just three times, which is the pending number of executions, as soon as interrupt becomes available.
• Precede Fixed Scan
When a pending execution exists, it is performed within the delay limit value behind a cycle. ( Page 58 Delay limit value
behind a cycle) Note that, even if more than one pending execution exists, only one execution is performed.
Cycle interval of TEISYU
"TEISYU"
(Fixed scan execution type program)
(1)
Section where interrupts
are disabled
Section where interrupts
are disabled
Execution cause:
6 times
Number of
executions: 6 times
Delay behind the cycle
Execution cause:
6 times
Number of
executions: 4 times
1 RUNNING A PROGRAM
1.5 Program Execution Type
1
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