As described earlier, there are many data sources you can use to animate the properties of an object. Another valuable option is to use an expression. An expression is a data value or multiple data values connected with one or more operators. Using the Expression Builder, you can create specific expressions that access data from unique sources. This gives you more flexibility when assigning dynamic object properties.
You can use the following data values in an expression:
- Numeric constants.
- Strings enclosed in quotation marks (" ").
- iFIX tags.
- Proficy Historian tags.
- OPC server I/O addresses.
- Picture properties.
- Object properties.
NOTE: Fetching data limits at runtime for an expression with more than one data source is not supported and may produce unexpected results at runtime. This is because there could be different tag names in the expression and it may not be clear which tag to fetch the limits for.
See Also
Using the Expression Builder Dialog Box
Customizing the Expression Builder
Specifying Tolerance, Deadband, and Refresh Rate
