Hi all,

I have created a DB in which I have several variables of Struct type.

Now in CFC, I want to move  values to one of the sub elements of the struct variables, but I am not allowed to do that. Please check the snips.

any suggestion?

CFC access to a sub element of a STRUCT is forbidden except for very limited scenarios such as implicit 'default APL PV' struct (Real + quality byte) to Real.

Since you have created a custom struct you will need to create a block like APL Library StruAnIn (or the opposite polarity StruAnOu), but adapted to your structure.  1 block will be needed for each unique struct with your In variable matching your UDT/Struct. I'd recommend defining UDTs so that in case you change the Structs later it's done centrally.  

Or you can just choose to adapt your DB to not nest the STRUCT inside the DB and just have all the variables individually.

EDIT:

If you only want to modify 1 value at a time, you'll have to leverage IN/OUT variables for the DB interface Struct but this will be trickier.