WaitForMultipleItemValues(IEasyDAClient,IReadOnlyList<DAItemGroupArguments>,DAQuality) 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), _
   ByVal minimumQuality As DAQuality _
) As ValueResult()

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

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

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

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).
minimumQuality: The minimum quality of OPC-DA data to accept.

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

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