LS Industrial Systems MASTER-K80S, Руководство пользователя

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Chapter 5 CPU Module
5-
１１
5.3 Program
5.3.1 Classification of program
All functional elements need to execute a certain control process are called as a ‘program’. In MASTER-K series, a program is
stored in the RAM mounted on a CPU module or flash memory of a external memory module. The following table shows the
classification of the program.
Program type Description
Scan program
The scan program is executed regularly in every scan. If the scan program is
not stored, the CPU cannot execute not only the scan program but also other
programs.
Time-driven interrupt
program (TDI) The TDI programs are executed with a constant time interval specified with
parameter setting.
Process driven
interrupt program
(PDI)
The PDI programs are executed only external interrupt input is applied and
the corresponding interrupt routine is enabled by EI instruction.
Subroutine program
The subroutine programs are executed when they are called by the scan
program with a CALL instruction.
5.3.2 Processing method
The following diagram shows that how the CPU module process programs when the CPU module is powered on or
switched to RUN mode.
Start operation
Scan program
END processing
Subroutine program
PDI program
TDI program