Value ranges, measurement units, and an initial value

Discrete, integer, real, and message tags are assigned an initial value when the InTouch application starts in WindowViewer. In the case of a discrete tag, the initial value is one of the possible binary states. For integer and real tags, the initial value is the number associated with the tag when the application starts. The initial value is specified in the Tagname Dictionary.

You can specify the initial tag value to be the last value of the tag when the application stops running in WindowViewer. By selecting the Retentive Value option from the Tagname Dictionary, the tag is assigned its last active value as the initial value when the application starts again.

Integer and real tags include properties that set the lower and upper boundaries of the range of possible numerical values assigned to a tag. Both integer and real tags include the Min Value and the Max Value properties that define the lower and upper limits of the range.

Integer and real tags also include the Eng Units property to assign an engineering units label that describes the unit of measure for the tag’s value. For example, you can assign PSI as the Eng Units property for an integer tag associated with pump pressure.