Справочник Пользователя для Mitsubishi Electronics MELSEC -Q/L
7 APPLICATION INSTRUCTIONS
7.17 Program Control Instructions
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7
7.17
Program Control Instructions
Processing when the execution type is converted with the program control instruction is as follows.
Once the fixed scan execution type program is changed to another execution type, it cannot be returned to the
fixed scan execution type.
fixed scan execution type.
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.
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.
*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.
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.
type at the second next scan and later. If executed prior to the output OFF processing, the program control instruction is
ignored.
Execution type before
change
change
Executed Instruction
PSCAN
PSTOP
POFF
PLOW
Scan execution type
No change-remains scan
type execution.
type execution.
Becomes stand-by type.
Output turned OFF in next
scan.
Becomes stand-by type from
the next scan after that.
scan.
Becomes stand-by type from
the next scan after that.
Becomes low speed
execution type.
execution type.
Initial execution type
Becomes scan execution
type.
type.
Stand-by type
No change-remains stand-by
type
type
Ignored
Low speed execution type
Low speed execution type
execution is stopped,
becomes scan execution
type from the next scan.
(Execution from step 0)
execution is stopped,
becomes scan execution
type from the next scan.
(Execution from step 0)
Low speed execution type
execution is stopped,
becomes stand-by type from
next scan.
execution is stopped,
becomes stand-by type from
next scan.
Low speed execution type
execution is stopped, and
output is turned OFF in the
next scan. Becomes stand-by
type from the next scan after
that.
execution is stopped, and
output is turned OFF in the
next scan. Becomes stand-by
type from the next scan after
that.
No change -remains low
speed execution type.
speed execution type.
Fixed scan execution type
Becomes scan execution
type.
type.
Becomes stand-by type.
Output turned OFF in next
scan.
Becomes stand-by type from
the next scan after that.
scan.
Becomes stand-by type from
the next scan after that.
Becomes low speed
execution type.
execution type.
• 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.
execution.
• 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.
processing.
END processing
"ABC"
GHI
GHI
*1
*1
DEF
GHI
PSTO executes "ABC"
PSCAN executes "DEF"
PSCAN executes "DEF"
Execution
program name
program name
GHI
END processing
END processing
Converts "DEF" into the scan execution
type program and "ABC" to the stand-by
type program
type program and "ABC" to the stand-by
type program