In addition to entering a data source directly, you can also select one from a list using the Expression Builder dialog box. This dialog box lets you select the data source you want to use, or create expressions by combining two or more data sources together.
You can select data sources from the Expression Builder dialog box by clicking the tab you want and selecting the source from the list. For example, to select an iFIX tag AI1 in the SCADA server SCADA01:
- Click the FIX32 Database tab.
- In the Node Names list, select SCADA01.
- In the Tag Names list, select the desired tag.
If an existing object contains properties, you can also select those properties from a list. For example, to select the Width property of a picture window:
- Click the Pictures tab.
- Select the picture you want to modify.
- In the Properties list, click the WindowWidth property.
As you make selections from the Expression Builder, the text in the lower window changes to match your selections, enabling you to create an expression. If applicable, the tolerance, deadband, or refresh rate also appear in this window. The section Building Expressions describes how to create expressions, and describes the components of the Expression Builder.
