Reference data type

A reference is a variable which only contains a link to a variable or to a function block instance. The used variable may be of elementary or derived data type.

• A reference is declared using the keyword REFERENCE TO. Then, the name of the referrede data type follows.
• The pointer is initialised using the REF= operator.

VAR
    MyRef : REF_TO INT;
    MyVar : INT;
END_VAR
 
MyVar := 100;
MyRef := REF(MyVar); //setting of a reference to a variable
MyRef := 200;        //there is a new value of 200 in the variable now