Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 371
Array (File)/Misc. Instructions (FAL, FSC, COP, CPS, FLL, AVE, SRT, STD, SIZE) Chapter 8
The number of bytes copied is:
Byte Count = Length ∗ (number of bytes in the Destination data type)
Arithmetic Status Flags: Not affected
Fault Conditions: None
ATTENTION: If the byte count is greater than the length of the Source, unpredictable
data is copied for the remaining elements.
You must test and confirm that the instruction doesn’t change data that you don’t
want it to change.
The COP and CPS instructions operate on contiguous memory. They do a straight
byte-to-byte memory copy. In some cases, they write past the array into other
members of the tag. This happens if the length is too big and the tag is a user-
defined data type.
The Length is too big if it is more than the total number of elements in the
Destination array.
If the tag is Then
User-defined data type If the Length is too big, the instruction writes past the end of the
array into other members of the tag. It stops at the end of the tag. No
major fault is generated.
NOT user-defined data type If the Length is too big, the instruction stops at the end of the array.
No major fault is generated.
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