Sfc Program Start And Stop - Mitsubishi Q series Programming Manual

6 SFC PROGRAM EXECUTION
6. SFC PROGRAM EXECUTION

6.1 SFC Program START And STOP

There are the following three types of SFC program start and stop methods.
• Auto START using PLC parameter
• Start and stop using the special relay for SFC program start/stop (SM321)
• Start and stop using the PSCAN/POFF instruction (except the Basic model QCPU)
• Start and stop using GX Developer (except the Basic model QCPU and Universal model QCPU)
(1) Auto START using PLC parameter
Set the start condition in the "SFC setting" of the PLC parameter dialog box to "Block 0 Auto
START".
The SFC program is started when the CPU module switches from STOP to RUN.
(When the SFC program starts, block 0 also starts.)
(2) Start and stop using the special relay for SFC program start/stop (SM321)
SM321 turns ON when an Auto START is made using the PLC parameter.
(a) Turn OFF SM321 to stop the SFC program execution.
(b) Turn ON SM321 to start the SFC program.
(3) Start and stop using the PSCAN/POFF instruction (except the Basic model
QCPU)
SM321 turns ON when an Auto START is made using the PLC parameter.
(a) When the POFF instruction is executed, the SFC program in execution turns off the output
and then stops.
The execution type changes to the "stand-by type".
(b) When the PSCAN instruction is executed, the stand-by type SFC program can be started.
However, when the SFC program has not been set to the "scan execution type" (SM321 is
OFF) in the program setting of the PLC parameter dialog box, the SFC program is started
by turning ON Sm321.
The execution type changes to the "scan execution type".
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