The Expression Builder also lets you define the tolerance, deadband, and refresh rate of a data source connection. These three fields, located at the bottom-right of the dialog box, are defined as follows:
- Tolerance – the allowable deviation from a value when evaluating an expression.
- Deadband – how much the current data value can deviate from the most recent data value.
- Refresh Rate – how often the data source connection updates, in seconds.
All three of these characteristics apply to a particular connection; they are not global. For example, if you connect the object RECT2.PROP1 to source FIX32.NODE.TAG.F_CV, you can specify different refresh rates for the rectangles properties, even though the object references the same database tag.
To enter a refresh rate enter a rate, in seconds, in the Refresh Rate field. Refer to the following table to determine how fast the connections will update based on the refresh rate you enter.
To enter a tolerance or deadband limit, enter a value in the Tolerance or Deadband fields, respectively.
NOTE: The Tolerance setting in the Expression Builder is for the expression only. To set the tolerance for an Exact Match Lookup Table, you must use the Animations Dialog box. For more information, refer to the Classifying Animations Errors section.
For more information on refresh rate, refer to the Increasing the Refresh Rate section in the Setting up the Environment manual.
