Mitsubishi MELSEC-A series, Programming Manual

Page: 187 / 508

6. BASIC INSTRUCTIONS
6
−
75
MELSEC-A
Execution of P Instruction Used with CHG Instruction
(1) When the A3 is used, execution contents of the PLS instruction change with
status of M9050 when other input conditions are same.
Status of M9050
OFF ON
Ladder example
The following program is written at step 0 of the main and subsequence programs.
Timing chart
OFF MOVP instruction is not executed. MOVP instruction is not executed.
ON
The MOVP instruction is executed during the first
scan after switched by the CHG instruction.
MOVP instruction is only executed during the first
scan of the subsequence program selected by the
CHG instruction executed after X0 is switched on.
Operation
depending
on X0
ON/OFF
status
OFF
↓
ON
MOVP instruction is only executed once. MOVP instruction is only executed once.
(2) When the A3N, A73 and A3V are used, execution contents are always same.
Ladder example
The following program is written at step 0 of the main and subsequence programs.
Timing chart
OFF MOVP instruction is not executed.
ON
MOVP instruction is only executed duing the first scan of the subsequence program selected by the CHG
instruction executed after X0 is switched on.
Operation
depending
on X0
ON/OFF
status
OFF
↓
ON
MOVP instruction is only executed once.
CHG instruction execution
1 scan
Main sequence
program run
Subsequence
program run
X0
MOVP
CHG instruction execution
CHG instruction execution
1 scan
Main sequence
program run
Subsequence
program run
X0
MOVP
CHG instruction execution
CHG instruction execution
1scan
Main sequence
program run
Subsequence
program run
X0
MOVP
CHG instruction execution
MOV
P
X000
X000
MOV 0 D0
P K