Fig. 3 shows the web application developed using Google Web Toolkit for
displaying the real-time values of PLC tags in a web browser. It uses the GTI, sitting
on the server side, to establish connection to the PLC at the user-defined address,
retrieve the list of its tags and feed the values to the client. There is a push-like
mechanism implemented for propagating a tag value change to the web browser,
where only a corresponding row in the table is dynamically updated.