OPC Studio User's Guide and Reference
DAVtq Constructor(Object,DateTime,DAQuality)



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.DataAccess Namespace > DAVtq Class > DAVtq Constructor : DAVtq Constructor(Object,DateTime,DAQuality)
The actual data value.

The value of this parameter can be null (Nothing in Visual Basic).

The timestamp of the data.
The quality of the data.

Because the DAQuality has an implicit conversion from System.Int32 and 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 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 DAQuality Constructor(Int32) or DAQuality Constructor(DAQualities) constructor instead.

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

Initializes a new instance of the class, with the specified data value, timestamp and quality.
Syntax
'Declaration
 
Public Function New( _
   ByVal value As Object, _
   ByVal timestamp As Date, _
   ByVal quality As DAQuality _
)
'Usage
 
Dim value As Object
Dim timestamp As Date
Dim quality As DAQuality
 
Dim instance As New DAVtq(value, timestamp, quality)

Parameters

value
The actual data value.

The value of this parameter can be null (Nothing in Visual Basic).

timestamp
The timestamp of the data.
quality
The quality of the data.

Because the DAQuality has an implicit conversion from System.Int32 and 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 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 DAQuality Constructor(Int32) or DAQuality Constructor(DAQualities) constructor instead.

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

Exceptions
ExceptionDescription

One of the arguments provided to a method is not valid.

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.

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

See Also