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Examples

The Result Value Selector is a text string that determines the specific piece (or pieces) of information that will be extracted and displayed from a target object.

The result value selector can have one of two forms:

   successAndFailureElementPath

   successElementPath ; failureElementPath

where

successAndFailureElementPath is an element path in the target object that will be used regardless of whether the operation has succeeded or failed.
successElementPath is an element path in the target object that will be used when the operation has succeeded.
failureElementPath is an element path in the target object that will be used when the operation has failed.

In the second case, the elements paths are separated by a semicolon.

When used for defining columns, the failureElementPath is only effective when the Column Kind is set to Arguments (and not to other kinds such as Point or Parameters).

Each element path can be either

Empty. In this case, the target object as such will be the result of the extraction.
A string constant, enclosed in doublequotes. The string will become the extracted value.
A name of a property of the target object, optionally followed by names of sub-properties and so forth; the names are separated by dots. A value of the selected property (or its subproperty) will be extracted.

The types of target objects (point, parameters, and arguments), and therefore the names and meaning of their properties, can be found in Point Types Reference.

Examples

Always extract the ErrorMessage property from the target object:

   ErrorMessage

Always extract the Value property from the target object:

   Value

Extract the Value property from the target object when the operation succeeded; return an empty string when the operation has failed:

   Value;""

Extract the Value property from the target object when the operation succeeded; return "N/A" when the operation has failed:

   Value;"N/A"

Extract the Value property from the target object when the operation succeeded; extract the ErrorMessage property when the operation has failed:

   Value;ErrorMessage

Extract the Vtq property (OPC-DA) from the target object when the operation succeeded; extract the ErrorMessage property when the operation has failed:

   Vtq;ErrorMessage

Extract the AttributeData property (OPC-UA) from the target object when the operation succeeded; extract the ErrorMessage property when the operation has failed:

   AttributeData;ErrorMessage

Reference

Point Types Reference