Mitsubishi 00JCPU, Руководство пользователя

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(5) Precautions
(a) Interrupt counter and interrupt program execution
One interrupt pointer cannot be used for both interrupt counting and interrupt program execution.
Once the interrupt counter is set in the PLC system tab of the PLC parameter dialog box, interrupt programs
are not executable.
(b) When counting processing is suspended
If an interrupt occurs during execution of the processing shown below, counting is suspended until the
execution of each processing is completed.
• Each instruction on the sequence program
• Interrupt program
• Fixed scan execution type program
Upon completion of the processing, the counting restarts.
However, if the same interrupt occurs again during each processing, these interrupts are counted as once.
(c) Maximum counting speed of the interrupt counter
The maximum counting speed is determined by one of the longest processing time among the following:
• Processing time for the instruction that needs the longest time in the program
• Processing time for an interrupt program
• Processing time for a fixed scan execution type program
(d) When too many points are used for the interrupt counter
The processing time of the sequence program will increase, and "WDT ERROR" may occur.
If this occurs, reduce the number of interrupt counter points or slow down the input pulse signal counting
speed.
(e) Resetting the interrupt counter
Use the RST C instruction in the main routine program.
(f) Reading the count value
The interrupt counter's count value can be read out with the MOV instruction in the sequence program.