QuickOPC User's Guide and Reference
WaitForMultipleItemValueList Method (_EasyDAClient)



OpcLabs.EasyOpcClassic Assembly > OpcLabs.EasyOpc.DataAccess.ComTypes Namespace > _EasyDAClient Interface : WaitForMultipleItemValueList Method
List of OPC-DA item group arguments (each argument holds an OPC server and item descriptor, and OPC group parameters).
The minimum quality of OPC-DA data to accept.
The number of milliseconds to wait, or System.Threading.Timeout.Infinite to wait indefinitely.
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
'Declaration
 
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Function WaitForMultipleItemValueList( _
   ByVal itemGroupArgumentsList As IList, _
   ByVal minimumQuality As Object, _
   ByVal millisecondsTimeout As Integer _
) As _ElasticVector
'Usage
 
Dim instance As _EasyDAClient
Dim itemGroupArgumentsList As IList
Dim minimumQuality As Object
Dim millisecondsTimeout As Integer
Dim value As _ElasticVector
 
value = instance.WaitForMultipleItemValueList(itemGroupArgumentsList, minimumQuality, millisecondsTimeout)
[ElementsNotNull()]
[NotNull()]
_ElasticVector WaitForMultipleItemValueList( 
   IList itemGroupArgumentsList,
   object minimumQuality,
   int millisecondsTimeout
)
[ElementsNotNull()]
[NotNull()]
_ElasticVector^ WaitForMultipleItemValueList( 
   IList^ itemGroupArgumentsList,
   Object^ minimumQuality,
   int millisecondsTimeout
) 

Parameters

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.
millisecondsTimeout
The number of milliseconds to wait, or System.Threading.Timeout.Infinite to wait indefinitely.

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, itemGroupArgumentsList.
Exceptions
ExceptionDescription

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.

The value of an argument is outside the allowable range of values as defined by the invoked method.

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

See Also