6.2 Instructions for Moving Data
The PLC uses data registers for storing measurements, output values, intermediate results of
operations and table values.The controller’s math instructions can read their operands directly
from the data registers and can also write their results back to the registers if you want. How
-
ever, these instructions are also supported by additional “move" instructions, with which you
can copy data from one register to another and write constant values to data registers.
6.2.1 Moving individual values with the MOV instruction
The MOV instruction “moves” data from the specified source to the specified destination.
NOTE Note that despite its name this is actually a copy process – it does not delete the data from
the source location.
쐃
Data source (this can also be a constant). The "s" in Ladder Diagram instructions means
source
.
쐇
Data destination (In Ladder Diagram instructions, "d" means
destination.
In the example the value in data register D10 will be copied to register D200 when input X1 is
on. This results in the following signal sequence:
Pulse-triggered execution of the MOV instruction
In some applications it is better if the value is written to the destination in one program cycle
only. For example, you will want to do this if other instructions in the program also write to the
same destination or if the move operation must be performed at a defined time.
Ifyouadda“P”totheMOVinstruction(MOVP)itwillonlybeexecutedonce, on the rising edge
of the signal pulse generated by the input condition.
6–12 MITSUBISHI ELECTRIC
Instructions for Moving Data More Advanced Programming
Ladder Diagram
MELSEC Instruction List
LD X1
MOV D10
D200
IEC Instruction List
LD X1
MOV_M D10, D200
D10
D200
X001
t
5384
5384
2271
963
963
125
The contents of the data source will be cop
-
ied to the data destination as long as the
input condition evaluates true. The copy
operation does not change the contents of
the data source.
When the input condition is no lon
-
ger true the instruction will no lon
-
ger change the contents of the data
destination.
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