Mitsubishi QCPU (Q Mode), Руководство пользователя

Страница: 43 / 456

4 - 3 4 - 3
MELSEC-Q
4 SEQUENCE PROGRAM CONFIGURATION AND EXECUTION
CONDITIONS
4.1.1 Main routine program
(1) Definition of main routine program
(a) A main routine program begins from step 0 and ends at the END/FEND
instruction. 1
(b) In the main routine program, the instructions are executed from step 0 to the
END/FEND.
1) If only one program is executed, the program is operated from step 0
again after the END/FEND instruction is executed and the END
instruction is processed.
END/FEND
Main routine
program
Step 0
END/FEND
END processing
Program execution
Returns to step 0 when only one
program is being executed.
2) If multiple programs are being executed, each of them will be operated
according to the designated execution conditions after the END/FEND
instruction is processed.
(2) Execution conditions for main routine programs 2
If multiple programs are being executed, the following five types of execution
conditions can be designated by the program in the PLC parameters according to
the application.
• Initial execution program : See Section 4.2.1.
• Scan execution type program : See Section 4.2.2.
• Low speed execution type program : See Section 4.2.3.
• Stand-by type program : See Section 4.2.4.
• Fixed scan execution type program : See Section 4.2.5.
REMARK
1: For details on the END/FEND instruction, refer to the "QCPU (Q
mode)/QnACPU Programming Manual (Common Instructions)".
2: If only one program is executed, it is processed under the "scan execution type
program" condition without designation by the program in the PLC parameters.