GetItemPropertyRecord(IEasyDAClient,ServerDescriptor,DANodeDescriptor) Method

Obtains a structure filled with OPC property values of all well-known OPC properties for a given OPC item.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<JetBrains.Annotations.NotNullAttribute()>
Public Overloads Shared Function GetItemPropertyRecord( _
   ByVal client As IEasyDAClient, _
   ByVal serverDescriptor As ServerDescriptor, _
   ByVal nodeDescriptor As DANodeDescriptor _
) As DAItemPropertyRecord

'Usage
 
Dim client As IEasyDAClient
Dim serverDescriptor As ServerDescriptor
Dim nodeDescriptor As DANodeDescriptor
Dim value As DAItemPropertyRecord
 
value = IEasyDAClientExtension2.GetItemPropertyRecord(client, serverDescriptor, nodeDescriptor)

[Extension()]
[JetBrains.Annotations.NotNull()]
public static DAItemPropertyRecord GetItemPropertyRecord( 
   IEasyDAClient client,
   ServerDescriptor serverDescriptor,
   DANodeDescriptor nodeDescriptor
)

[Extension()]
[JetBrains.Annotations.NotNull()]
public:
static DAItemPropertyRecord^ GetItemPropertyRecord( 
   IEasyDAClient^ client,
   ServerDescriptor^ serverDescriptor,
   DANodeDescriptor^ nodeDescriptor
)

Parameters

client

The client object that will perform the operation.

This is typically the OpcLabs.EasyOpc.DataAccess.EasyDAClient object.

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

serverDescriptor

The OPC server involved in the operation.

Because the OpcLabs.EasyOpc.ServerDescriptor has an implicit conversion from System.Guid, System.String and OpcLabs.EasyOpc.ServerElement, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a GUID (representing the CLSID of the server), a string (representing the so-called OPC server descriptor string, such as a ProgID or the URL of the server), or a OpcLabs.EasyOpc.ServerElement object (result from OPC browsing), in place of this parameter, and the corresponding OPC server descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.ServerDescriptor.FromGuid, OpcLabs.EasyOpc.ServerDescriptor.FromString or OpcLabs.EasyOpc.ServerDescriptor.FromServerElement static method instead.

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

nodeDescriptor

The descriptor of the OPC node involved in the operation.

Because the OpcLabs.EasyOpc.DataAccess.DANodeDescriptor has an implicit conversion from System.String and OpcLabs.EasyOpc.DataAccess.AddressSpace.DANodeElement, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the qualified name of the node), or a OpcLabs.EasyOpc.DataAccess.AddressSpace.DANodeElement object (result from OPC browsing), in place of this parameter, and the corresponding OPC DA node descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the FromString or FromDANodeElement static method instead.

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

Return Value

Returns a structure containing the OPC property values requested.

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

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.
OpcLabs.EasyOpc.OperationModel.OpcException	The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause. This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

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.

OpcLabs.EasyOpc.OperationModel.OpcException

The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Remarks

The server(s) can be local or can be remotely accessed via DCOM.

This method allows you to obtain a structure filled in with property values for a given OPC item. It can retrieve all well-known properties at once, or you can pass in a set of property Ids that you are interested in. You can then simply use the properties in the resulting DAItemPropertyRecord structure, without further looking up the values in any way.

Using implicit conversions, you can pass an item ID in place of node descriptor.

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.

Example

CSharp
VB.NET
Python

// This example shows how to obtain a structure containing property values for an OPC item, and display some property values.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.Extensions;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClientExtension
{
    class GetItemPropertyRecord
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            // Get a structure containing values of all well-known properties
            DAItemPropertyRecord itemPropertyRecord;
            try
            {
                itemPropertyRecord = client.GetItemPropertyRecord("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display some of the obtained property values
            Console.WriteLine("itemPropertyRecord.AccessRights: {0}", itemPropertyRecord.AccessRights);
            Console.WriteLine("itemPropertyRecord.DataType: {0}", itemPropertyRecord.DataType);
            Console.WriteLine("itemPropertyRecord.Timestamp: {0}", itemPropertyRecord.Timestamp);
        }
    }
}

' This example shows how to obtain a structure containing property values for an OPC item, and display some property values.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.Extensions
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess._EasyDAClientExtension
    Friend Class GetItemPropertyRecord
        Public Shared Sub Main1()
            Dim client = New EasyDAClient()

            ' Get a structure containing values of all well-known properties
            Dim itemPropertyRecord As DAItemPropertyRecord
            Try
                itemPropertyRecord = client.GetItemPropertyRecord("", "OPCLabs.KitServer.2", "Simulation.Random")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            ' Display some of the obtained property values
            Console.WriteLine("itemPropertyRecord.AccessRights: {0}", itemPropertyRecord.AccessRights)
            Console.WriteLine("itemPropertyRecord.DataType: {0}", itemPropertyRecord.DataType)
            Console.WriteLine("itemPropertyRecord.Timestamp: {0}", itemPropertyRecord.Timestamp)
        End Sub
    End Class
End Namespace

# This example shows how to obtain a structure containing property values for an OPC item, and display some property
# values.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.DataAccess.Extensions import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Get a structure containing values of all well-known properties.
try:
    itemPropertyRecord = IEasyDAClientExtension2.GetItemPropertyRecord(client,
                                                                       '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display some of the obtained property values.
print('itemPropertyRecord.AccessRights: ', itemPropertyRecord.AccessRights, sep='')
print('itemPropertyRecord.DataType: ', itemPropertyRecord.DataType, sep='')
print('itemPropertyRecord.Timestamp: ', itemPropertyRecord.Timestamp, sep='')

print('Finished.')

CSharp
VB.NET
Python

// This example shows how to obtain a structure containing property values for an OPC item, and display some property values.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.Extensions;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClientExtension
{
    class GetItemPropertyRecord
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            // Get a structure containing values of all well-known properties
            DAItemPropertyRecord itemPropertyRecord;
            try
            {
                itemPropertyRecord = client.GetItemPropertyRecord("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display some of the obtained property values
            Console.WriteLine("itemPropertyRecord.AccessRights: {0}", itemPropertyRecord.AccessRights);
            Console.WriteLine("itemPropertyRecord.DataType: {0}", itemPropertyRecord.DataType);
            Console.WriteLine("itemPropertyRecord.Timestamp: {0}", itemPropertyRecord.Timestamp);
        }
    }
}

' This example shows how to obtain a structure containing property values for an OPC item, and display some property values.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.Extensions
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess._EasyDAClientExtension
    Friend Class GetItemPropertyRecord
        Public Shared Sub Main1()
            Dim client = New EasyDAClient()

            ' Get a structure containing values of all well-known properties
            Dim itemPropertyRecord As DAItemPropertyRecord
            Try
                itemPropertyRecord = client.GetItemPropertyRecord("", "OPCLabs.KitServer.2", "Simulation.Random")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            ' Display some of the obtained property values
            Console.WriteLine("itemPropertyRecord.AccessRights: {0}", itemPropertyRecord.AccessRights)
            Console.WriteLine("itemPropertyRecord.DataType: {0}", itemPropertyRecord.DataType)
            Console.WriteLine("itemPropertyRecord.Timestamp: {0}", itemPropertyRecord.Timestamp)
        End Sub
    End Class
End Namespace

# This example shows how to obtain a structure containing property values for an OPC item, and display some property
# values.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.DataAccess.Extensions import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Get a structure containing values of all well-known properties.
try:
    itemPropertyRecord = IEasyDAClientExtension2.GetItemPropertyRecord(client,
                                                                       '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display some of the obtained property values.
print('itemPropertyRecord.AccessRights: ', itemPropertyRecord.AccessRights, sep='')
print('itemPropertyRecord.DataType: ', itemPropertyRecord.DataType, sep='')
print('itemPropertyRecord.Timestamp: ', itemPropertyRecord.Timestamp, sep='')

print('Finished.')

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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Missing some example? Ask us for it on our Online Forums! You do not have to own a commercial license in order to use Online Forums, and we reply to every post.