Can I use"Arrays" in Function designer?

Datatype: "Arraytype" can not be sent as a Communication variable.

Yes, you can use Arrays in function designer, but remember all the logic around Array should be in a single diagram. If you want to use Array out of diagram then it is not possible. Array datatype is not supported for communication variable communication. (In simple terms MMS between diagrams).

We recommend to use structure text when it comes to Arrays.