WaitForMultipleItemValues(IEasyDAClient,IReadOnlyList<DAItemGroupArguments>) Method

Subscribes to the specified OPC-DA items, and monitors their data until they have at least the quality specified for each item, an error occurs, or the alloted time elapses.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function WaitForMultipleItemValues( _
   ByVal client As IEasyDAClient, _
   ByVal itemGroupArgumentsList As IReadOnlyList(Of DAItemGroupArguments) _
) As ValueResult()

'Usage
 
Dim client As IEasyDAClient
Dim itemGroupArgumentsList As IReadOnlyList(Of DAItemGroupArguments)
Dim value() As ValueResult
 
value = IEasyDAClientExtension2.WaitForMultipleItemValues(client, itemGroupArgumentsList)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static ValueResult[] WaitForMultipleItemValues( 
   IEasyDAClient client,
   IReadOnlyList<DAItemGroupArguments> itemGroupArgumentsList
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static array<ValueResult^>^ WaitForMultipleItemValues( 
   IEasyDAClient^ client,
   IReadOnlyList<DAItemGroupArguments^>^ itemGroupArgumentsList
)

Parameters

client: The client object that will perform the operation.
itemGroupArgumentsList: List of OPC-DA item group arguments (each argument holds an OPC server and item descriptor, and OPC group parameters).

Return Value

The function returns an array of OpcLabs.BaseLib.OperationModel.ValueResult objects. The indices of elements in the output array are the same as those in the input list, .

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	A `null` reference (`Nothing` in Visual Basic) is passed to a method that does not accept it as a valid argument. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

System.ArgumentNullException

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

IEasyDAClientExtension2 Class
IEasyDAClientExtension2 Members
Overload List

Send Documentation Feedback. Resources: Knowledge Base. Technical support: Online Forums, FAQ.