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4.8.13
Move Data Explicit
MOVE_DATA_EX Operands
Parameter Description
Length (??) The length of IN; the number of elements to copy.
1 Length 32,767
DC
Data coherency.
If True memory being written to is locked, enabling
coherent copying of data from one Controller memory
area to another.
If False (default), data is copied normally from one
Controller memory area to another without data
coherency.
▪
The input DC should be used only when using
interrupt blocks and is required only when the same
memory is used in more than one interrupt block, or
in the main program and an interrupt block.
▪
If DC is True, an interrupt block cannot preempt the
copy operation.
▪
If DC is False or not present, then interrupts can
preempt the copy.
▪
Using DC can impact interrupt latency if the amount
of data copied is large.
IN
The location of the data item to copy.
If IN is 0 (LD only), length is assigned the constant 1 and
the variable or structure assigned to Q is set to its default
value.
Q
Variable or array to which IN is copied.
Q must be the same data type as IN, unless IN is the
constant 0.
Example
Enum_Array and Enum_Array_Out are arrays of
enumerated variables, with three elements each.
To copy all elements in Enum_Array, input Length
should be 3. When the enabling input Q00014 is
on, MOVE_DATA_EX copies three elements from
memory location Enum_Array to memory
location Enum_Array_Out.
GFK-2950C
MOVE_DATA_EX provides optional data coherency by locking the
symbolic memory being written to during the copy operation. This allows
data to be copied coherently when accessed by multiple logic threads (i.e.
interrupt blocks). Note that copying large amounts of data with coherency
enabled can increase interrupt latency.
February 2018
Chapter 4. Ladder Diagram (LD) Programming
Allowed Operands
Constant
Data flow.
Enumerated variable or
structure variable, or array
of these types; the constant
0.
Enumerated variable or
structure variable, or array
of these types.
Optional
No
Yes
No
No
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