Sfc Program For Program Execution Management - Mitsubishi Electric MELSEC-Q Series Programming Manual

SFC program for program execution management

This SFC program can be used to manage the program execution sequence when multiple program file switching is required.
In addition to a normal SFC program, only one block can be created and executed for a single file of an SFC program for
program execution management.
How to create SFC program for program execution management
This section describes how to create SFC program for program execution management.
■Number of files and blocks
In addition to a normal SFC program, only one file of an SFC program for program execution management can be created as
a scan execution type program. Only one block of the SFC program for program execution management can be created.
■Usable instructions
The SFC diagram symbols (except the block START steps) and steps that can be used in an SFC program and the sequence
instructions that can be used in transition conditions can all be used.
If block start steps are described, a "BLOCK EXE. ERROR" error (error No. 4621) will occur during SFC
program execution and the CPU module will stop the execution.
Execution procedure
The program is started automatically when registered as a scan execution type program. At end step processing, the initial
step is reactivated and processing is repeated.
• Use the peripheral device to select between the SFC program for program execution management and the
normal SFC program. For details regarding the setting procedure, refer to the GX Developer Operating
Manual (MELSAP-L).
• Periodic execution block settings cannot be defined the SFC programs for program execution control. If a
SFC program for program execution control is set in a periodic execution block, the execution of the SFC
program will not be performed.
• The Basic model QCPU, Universal model QCPU, and LCPU do not support SFC programs for program
execution management.
• The SFC program for program execution management cannot be set as a stand-by type program. In
addition, execution designation by POFF or PSCAN instruction cannot be applied to the program.
• The SFC control instructions cannot be executed for the SFC program for program execution management.
5 SFC PROGRAM PROCESSING SEQUENCE
150
5.2 Whole Program Processing of High Performance Model QCPU, Process CPU, Redundant CPU, Universal Model QCPU, and