Using the Expression Builder Dialog Box | iFIX 6.1 Documentation

The Expression Builder dialog box is your tool for creating expressions. This dialog box lets you select the data source you want to use or create expressions by combining two or more data sources together.

The Expression Builder dialog box is divided into multiple tabs, which are described in the following table.

Expression Builder Tabs
The tab...	Displays...
FIX Database	Any SCADA servers to which your computer is communicating. Use a data server as a data source when you want to animate an object or an iFIX tag. The tabbed page includes Node Names, Tag Names, and Field Names windows to help you specify your selections.
Pictures	The pictures residing on your computer. The Objects window displays each object in the picture. Use one of these objects as a data source when you want to animate an object with a picture or object property value. The Properties window displays the properties for the selected object so that you can select a specific property.
Globals	Global data sources. The tabbed page includes Objects and Properties windows to help you specify your selections.
Data Servers	Third party OPC servers. Data source connections to data servers fire at run-time only.
Alarm Counters	A filtered list of SCADA servers that your computer is communicating with. The tabbed page includes the Alarm AreaTag Names window that displays a filtered list of alarm areas on the selected SCADA and alarm counter tags. The Alarm Counter Field Names window displays a filtered list of fields available from the selected area.
GE Historian	Any GE Historian Server to which your computer is communicating. Use a GE Historian Server data source when you want to animate an object. The tabbed page includes Node Names and Tag Names windows to help you specify your selections.

When you select a data source, it appears in the field at the bottom of the dialog box. You can add strings by typing them into the field. You can also add operators and numeric constants by typing them into the field, or by clicking the operator buttons on the right side of the dialog box while the cursor is in the field. To display the operator buttons, click the Mathematical Functions button.

NOTE: If you have created an object-to-object connection, such as the fill percentage of one tank to another, or created a connection to a data source, the animated properties display in boldface in the Properties list of the Pictures tab for the selected object.

The Filter fields and buttons allow you to filter data sources. For more information, refer to the Filtering Data Sources section. Additionally, you can specify a tolerance, deadband, and refresh rate in the appropriate fields. These functions are described later in this section.

For more information on selecting data sources from the Expression Builder dialog box, including examples, refer to the Selecting Data Sources from a List section.

How Do I...

create an expression