AFCalculation.DetermineEvaluationServer Method
- Last UpdatedNov 18, 2025
- 2 minute read
- PI System
- AF SDK 2024 R2
- Developer
This method returns the server that the expression, with the specified target, will execute on.
Namespace: OSIsoft.AF.Data
Assembly: OSIsoft.AFSDK (in OSIsoft.AFSDK.dll) Version: 3.1.1.1182
Syntax
public static AFObject DetermineEvaluationServer( Object target, string expression )
Public Shared Function DetermineEvaluationServer ( target As Object, expression As String ) As AFObject Dim target As Object Dim expression As String Dim returnValue As AFObject returnValue = AFCalculation.DetermineEvaluationServer(target, expression)
public: static AFObject^ DetermineEvaluationServer( Object^ target, String^ expression )
static member DetermineEvaluationServer : target : Object * expression : string -> AFObject
Parameters
- target
- Type: SystemObject
The target can either be a PIServer, an AFDatabase, or any derived objects of AFBaseElement. References to attributes or points are based on the target. - expression
- Type: SystemString
A string containing the expression to be evaluated. The syntax for the expression generally follows the Performance Equation syntax as described in the PI Data Archive documentation, with the exception that expressions which target elements using attribute names in place of tag names in the equation.
Return Value
Type: AFObjectReturns the PIServer which will execute the expression. In future releases of AF, this may also be a PISystem, or if , the current client machine.
Remarks
Calculations are limited to Attributes or PI Points which originate from a single PI Data Archive. If a single evaluation
server cannot be found, an exception will be raised.