Fll, mov, cop

Would someone be so kind as to explain the difference between the cop, mov and cop instructions and where each one may be used? The instruction help description all seems to be similar.

Thank you

No problem Amy - and welcome to the forum !!

MOV - (is actually a copy, since the source is never changed), takes the contents of the source address or tag and puts it into the destination address or tag. It can only move one data "element" at a time, so cannot be used to copy arrays, or any other tag or data object that has a "structure". Nor can it be used to copy bits. Data conversion between different data-types is performed as necessary.

COP - copies areas of memory from the source to the destination. Can be used with arrays, and structured tags. NO DATA CONVERSION is even attempted, it is a fast "bit-copier". COPying between different data-types will corrupt the data.

CPS - (Only in Logix5000) just like the COP, but can't be interrupted by System Overhead Time-Slice, or higher priority tasks.

That's a simple overview - hope it helps.

Thank you daba, I find the forum very informative. How abou the FLL instructions?

it is just used to Fill an array or data-table with the value of a single source. That source can be another tag or address, or it can be a literal, like "0".... very useful for clearing data ...

Thank you! I appreciate the explanation.