Some data sources support the ability to write data back to a data source. This is useful if you want a user to be able to change the value of a tag in the data source through the Proficy Portal display, without having to load another application.
To change the value of a tag in the run-time environment, simply click on the datalink. A dialog box will appear, requesting a new value to be entered. If you have configured the datalink object to confirm writes, a dialog box will appear to confirm the new value.