OPC Studio User's Guide and Reference
WaitForMultipleItemValues Method (_EasyDAClient)



OpcLabs.EasyOpcClassic Assembly > OpcLabs.EasyOpc.DataAccess.ComTypes Namespace > _EasyDAClient Interface : WaitForMultipleItemValues Method

The value of this parameter cannot be null (Nothing in Visual Basic).

The minimum quality of OPC-DA data to accept.

Because the OpcLabs.EasyOpc.DataAccess.DAQuality has an implicit conversion from System.Int32 and OpcLabs.EasyOpc.DataAccess.DAQualities, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use an integer (representing the internal value of the quality), or an element of the OpcLabs.EasyOpc.DataAccess.DAQualities enumeration in place of this parameter, and the corresponding OPC DA quality object will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.DataAccess.DAQuality.DAQuality Constructor(Int32) or OpcLabs.EasyOpc.DataAccess.DAQuality.DAQuality Constructor(DAQualities) constructor instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

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

Valid values of this parameter are in the range from -1 to 2147483647 (Int32.MaxValue).

Waits until the OPC-DA items reach the given minimum quality. Specify arguments objects, minimum quality, and timeout in milliseconds.
Syntax
'Declaration
 
<NotNullAttribute()>
Function WaitForMultipleItemValues( _
   ByVal itemGroupArgumentsArray As Object, _
   ByVal minimumQuality As Object, _
   ByVal millisecondsTimeout As Integer _
) As Object()
'Usage
 
Dim instance As _EasyDAClient
Dim itemGroupArgumentsArray As Object
Dim minimumQuality As Object
Dim millisecondsTimeout As Integer
Dim value() As Object
 
value = instance.WaitForMultipleItemValues(itemGroupArgumentsArray, minimumQuality, millisecondsTimeout)

Parameters

itemGroupArgumentsArray

The value of this parameter cannot be null (Nothing in Visual Basic).

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

Because the OpcLabs.EasyOpc.DataAccess.DAQuality has an implicit conversion from System.Int32 and OpcLabs.EasyOpc.DataAccess.DAQualities, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use an integer (representing the internal value of the quality), or an element of the OpcLabs.EasyOpc.DataAccess.DAQualities enumeration in place of this parameter, and the corresponding OPC DA quality object will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.DataAccess.DAQuality.DAQuality Constructor(Int32) or OpcLabs.EasyOpc.DataAccess.DAQuality.DAQuality Constructor(DAQualities) constructor instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

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

Valid values of this parameter are in the range from -1 to 2147483647 (Int32.MaxValue).

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.

This method never returns null (Nothing in Visual Basic).

The individual elements of the returned value are never null (Nothing in Visual Basic).

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.

Remarks

This member or type is for use from COM. It is not meant to be used from .NET or Python. Refer to the corresponding .NET member or type instead, if you are developing in .NET or Python.

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

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