Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 139

Changing the execution type by an instruction
The execution type of a program can be changed by using a program control instruction.
The following table lists program control instructions with regard to whether an SFC program can be specified.
Instruction symbol Specification
enable/
disable

PSCAN
PSTOP 

POFF
Scan execution type
program
PSCAN POFF
instruction instruction
Standby type
program
■ Precautions
• Do not use the PSCAN instruction to read/write a file from/to the CPU module or use the data logging function. If the
PSCAN instruction is executed, the scan time may extend several hundred milliseconds.
• When the SFC program, which is different program from the one operated last time, is operated by using the PSCAN
instruction while specifying resume start, the specified SFC program performs the initial start. In this case, "SFC program
continuous start not possible" (event code: 0430) is saved in the event history.
Remarks
Changes the execution type of the specified SFC program to the scan execution type.
If this instruction is executed with another SFC program specified while an scan execution type SFC
program already exists, an error occurs.
If this instruction is executed for an SFC program, an error results.
Executes end processing of all blocks in the next scan and changes the execution type of the specified
SFC program to the standby type in the following scan.
8 SFC PROGRAM
8.6 SFC Program Execution Order
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