An instance of this function block type provides a read-only drop-down list interface. The strings in the drop-down list are taken from the comma-separated list at the CHOICES input. When an element is selected from the drop-down list, an IND event occurs with the string value of the selected element at the OUT output and the zero-based array index of the selected element at the I output.

See the CHOICE_TBL FB type for an example of the use of an instance of this FB type.