Namespace for Global Variables Lists

The operator is an extension of the IEC 61131-3 standard.

You can use the name of a global variable list (GVL) as namespace identifier for the variables defined in the list. This makes it possible to use variables with the same names in different global variable lists and still uniquely access a particular variable. The variable name should be preceded by the name of the global variable list, separated by a dot.

Syntax: <global variable list name>.<variable>

Example:

GVL1.nVar := GVL2.nVar;

The global variable lists GVL1 and GVL2 contain a variable nVar. TwinCAT copies the global variable nVar from the list GVL2 to nVar from the list GVL1.

An error message appears if you reference a variable that is declared in more than one global variable list without the preceding list name.