Mitsubishi MELSEC Q Series Programming Manual page 749

(2) As program execution type conversions by PSCAN and PSTOP instructions occur at the
END processing, such conversions are impossible during program execution.
When different execution types have been set for the same program in the same scan, the
execution type will be that specified by the execution switching command that was executed
last.
END processing
Execution
program name GHI
*1: The order of "GHI" and "DEF" program execution is determined by the program settings parameters.
Switching from the fixed scan execution type program to the execution type program is
performed in the following timing.
(a) For the Universal model QCPU, LCPU
The execution type is changed when the execution of the fixed scan execution type is
stopped at the END processing after the program control instruction execution.
(b) Basic model QCPU, High Performance model QCPU, Process CPU, and Redundant
CPU
The execution of the fixed scan execution type is stopped at the execution of the
program control instruction, and the execution type is changed at the END processing.
(3) When the POFF instruction is executed, the output is turned OFF at the next scan, and the
execution type will be the stand-by type at the second next scan and later.
If executed prior to the output OFF processing, the program control instruction is ignored.
END processing
"ABC" GHI GHI
PSTO executes "ABC" Converts "DEF" into the scan execution
type program and "ABC" to the stand-by
PSCAN executes "DEF"
type program
END processing
*1 *1
DEF GHI
1
2
3
4
6
6
7
8
7-375