====== 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 [[:en:mervis-ide:35-help:035-software_basic:035-data-types:005-elementary_data_types|elementary]] or [[:en:mervis-ide:35-help:035-software_basic:035-data-types:015-user_defined_data_types|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.

===== Example =====


<code st-iec>
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
</code>