Changing any behavior on a Screen can be performed using Links, in which a server automatically reports all changes in the selected variables to E3 Viewers, or by an explicit E3 Viewer's search for information in the server. The whole graphical interface linking operation is accomplished from client to server and not from server to client. Thus, users cannot change Screens or objects from the server by using scripts, because each data client is a different copy of these Screens.

A practical example is either to change the color of a text on a Screen to green when a Tag is turned on, that is, its value changes to 1 (one), or to red when it is turned off, that is, its value changes to 0 (zero). In this case, simply create a Digital Link between Text1's TextColor property and Tag1. Links are preferable due to execution speed and also simplicity in maintaining and building applications.

Linking text color to Tag1's value

Another way to execute the previous procedure is by creating a script in the Viewer that constantly checks whether Tag1 changed its value, and only then changes the text color. This type of script can be accomplished, but it strongly degrades application performance. Thus, this practice is not recommended.