Logix5000 Controllers General Instructions - SLAC Confluence

Array (File)/Misc. Instructions (FAL, FSC, COP, CPS, FLL, AVE, SRT, STD, SIZE) 359Description:During execution of the COP and CPS instructions, other controlleractions may try to interrupt the copy operation and change the sourceor destination data:If the Source Or Destination Is And You Want To Then Select Notes• produced tag• consumed tag• I/O dataprevent the data from changingduring the copy operationCPS• data that another task canoverwritenone of the aboveallow the data to change during thecopy operationCOPCOP• Tasks that attempt to interrupt a CPSinstruction are delayed until theinstruction is done.• To estimate the execution time of theCPS instruction, see ControlLogixSystem User Manual, publication1756-UM001.The number of bytes copied is:Byte Count = Length ∗ (number of bytes in the Destination data type)ATTENTIONIf the byte count is greater than the length of the Source, unpredictable data iscopied for the remaining elements.IMPORTANTYou must test and confirm that the instruction doesn’t change data that you don’twant it to change.The COP and CPS instructions operate on contiguous memory. They do a straightbyte-to-byte memory copy. In some cases, they write past the array into othermembers of the tag. This happens if the length is too big and the tag is auser-defined data type.If The Tag Isuser-defined data typeNOT user-defined datatypeThenIf the Length is too big, the instruction writes past the end ofthe array into other members of the tag. It stops at the end ofthe tag. No major fault is generated.If the Length is too big, the instruction stops at the end of thearray. No major fault is generated.The Length is too big if it is more than the total number of elements in theDestination array.Arithmetic Status Flags:Fault Conditions:not affectednonePublication 1756-RM003I-EN-P - January 2007