# Value connection (gauge and bar graph)

The application reads the value of the connection at the data source and updates the object’s display to reflect the value.

A read connection. You can assign a tag or an expression to this connection. If you assign an expression, the application calculates the value of the expression and updates the object’s display to reflect the value.

The gauge and bar graph graphic object elements have this connection within their connections elements.

## See also

connections and connection elements