Dear Friend

UTD is a structure which we can use in any Data Block or any function block if your memory structure is same for all other blocks or data, when we write IN , OUT in function block , we can give there direct UDT name so that u dont need to write that address structure once again for all.

If u read manual definitely you will get to know.

If any more queries contact on --Deleted E-Mail--. 

Hello.

You can imagine a UDT like a customizable complex data type, which structure is defined by you. You define what kind of data you will compose your "Complex Data". Once defined, you can use it just like the other data types, so it will keep the same structure.

I hope this can help you.