Mitsubishi MELSEC-A Series Programming Manual page 187

6. BASIC INSTRUCTIONS
Execution of P Instruction Used with CHG Instruction
The following program is written at step 0 of the main and subsequence programs.
Ladder example
Main sequence
program run
Subsequence
program run
Timing chart
X0
MOVP
OFF MOVP instruction is not executed.
Operation
The MOVP instruction is executed during the first
depending
ON
scan after switched by the CHG instruction.
on X0
ON/OFF
OFF
status
↓
MOVP instruction is only executed once.
ON
The following program is written at step 0 of the main and subsequence programs.
Ladder example
Timing chart
OFF MOVP instruction is not executed.
Operation
MOVP instruction is only executed duing the first scan of the subsequence program selected by the CHG
depending ON
instruction executed after X0 is switched on.
on X0
OFF
ON/OFF
↓
MOVP instruction is only executed once.
status
ON
(1) When the A3 is used, execution contents of the PLS instruction change with
status of M9050 when other input conditions are same.
OFF
1 scan
CHG instruction execution
(2) When the A3N, A73 and A3V are used, execution contents are always same.
Main sequence
program run
Subsequence
program run
X0
MOVP
Status of M9050
X000
P
MOV
Main sequence
program run
Subsequence
program run
CHG instruction execution
X0
MOVP
MOVP instruction is not executed.
MOVP instruction is only executed during the first
scan of the subsequence program selected by the
CHG instruction executed after X0 is switched on.
MOVP instruction is only executed once.
X000
P K
MOV 0
1scan
CHG instruction execution
CHG instruction execution
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MELSEC-A
ON
1 scan
CHG instruction execution
CHG instruction execution
D0