GetPropertyValueDictionary(IEasyDAClient,String,String,String) Method

Obtains a DAPropertyValueDictionary filled with OPC property values for a given OPC item. Obtains a dictionary filled with all well-known OPC property values for a given OPC item.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function GetPropertyValueDictionary( _
   ByVal client As IEasyDAClient, _
   ByVal machineName As String, _
   ByVal serverClass As String, _
   ByVal itemId As String _
) As DAPropertyValueDictionary

'Usage
 
Dim client As IEasyDAClient
Dim machineName As String
Dim serverClass As String
Dim itemId As String
Dim value As DAPropertyValueDictionary
 
value = IEasyDAClientExtension2.GetPropertyValueDictionary(client, machineName, serverClass, itemId)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static DAPropertyValueDictionary GetPropertyValueDictionary( 
   IEasyDAClient client,
   string machineName,
   string serverClass,
   string itemId
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static DAPropertyValueDictionary^ GetPropertyValueDictionary( 
   IEasyDAClient^ client,
   String^ machineName,
   String^ serverClass,
   String^ itemId
)

Parameters

client: The client object that will perform the operation.
machineName: Name of the machine. Determines the computer on which the OPC server is located. May be an empty string, in which case the OPC server is assumed to exist on the local computer or at the computer specified for it by DCOM configuration.
serverClass: Contains ProgID of the OPC server to read from.
itemId: Contains OPC item identifier.

Return Value

Returns a dictionary of OpcLabs.BaseLib.OperationModel.ValueResult objects keyed by OpcLabs.EasyOpc.DataAccess.DAPropertyId.

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.

Remarks

This method allows you to obtain a dictionary of property values for a given OPC item, where a key to the dictionary is the property Id. You can pass in a set of property Ids that you are interested in, or have the method obtain all well-known OPC properties. You can then easily extract the value of any property by looking it up in a dictionary (as opposed to having to numerically index into an array, as with the base OpcLabs.EasyOpc.DataAccess.IEasyDAClientExtension.GetMultiplePropertyValues method).

Example

// This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.

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

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

            // Get dictionary of property values, for all well-known properties
            DAPropertyValueDictionary propertyValueDictionary;
            try
            {
                propertyValueDictionary = client.GetPropertyValueDictionary("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display some of the obtained property values
            // The production code should also check for the .Exception first, before getting .Value
            Console.WriteLine("propertyValueDictionary[DAPropertyId.AccessRights].Value: {0}",
                propertyValueDictionary[DAPropertyIds.AccessRights].Value);
            Console.WriteLine("propertyValueDictionary[DAPropertyId.DataType].Value: {0}",
                propertyValueDictionary[DAPropertyIds.DataType].Value);
            Console.WriteLine("propertyValueDictionary[DAPropertyId.Timestamp].Value: {0}",
                propertyValueDictionary[DAPropertyIds.Timestamp].Value);
        }
    }
}

# This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.

# 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 dictionary of property values, for all well-known properties.
try:
    propertyValueDictionary = IEasyDAClientExtension2.GetPropertyValueDictionary(client,
        '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display some of the obtained property values.
# The production code should also check for the .Exception first, before getting .Value
print('propertyValueDictionary[DAPropertyId.AccessRights].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.AccessRights)).Value, sep='')
print('propertyValueDictionary[DAPropertyId.DataType].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.DataType)).Value, sep='')
print('propertyValueDictionary[DAPropertyId.Timestamp].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.Timestamp)).Value, sep='')

print('Finished.')

' This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.

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

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

            ' Get dictionary of property values, for all well-known properties
            Dim propertyValueDictionary As DAPropertyValueDictionary
            Try
                propertyValueDictionary = client.GetPropertyValueDictionary("", "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
            ' The production code should also check for the .Exception first, before getting .Value
            Console.WriteLine("propertyValueDictionary[DAPropertyId.AccessRights].Value: {0}", propertyValueDictionary(DAPropertyIds.AccessRights).Value)
            Console.WriteLine("propertyValueDictionary[DAPropertyId.DataType].Value: {0}", propertyValueDictionary(DAPropertyIds.DataType).Value)
            Console.WriteLine("propertyValueDictionary[DAPropertyId.Timestamp].Value: {0}", propertyValueDictionary(DAPropertyIds.Timestamp).Value)
        End Sub
    End Class
End Namespace

CSharp
Python
VB.NET

// This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.

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

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

            // Get dictionary of property values, for all well-known properties
            DAPropertyValueDictionary propertyValueDictionary;
            try
            {
                propertyValueDictionary = client.GetPropertyValueDictionary("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display some of the obtained property values
            // The production code should also check for the .Exception first, before getting .Value
            Console.WriteLine("propertyValueDictionary[DAPropertyId.AccessRights].Value: {0}",
                propertyValueDictionary[DAPropertyIds.AccessRights].Value);
            Console.WriteLine("propertyValueDictionary[DAPropertyId.DataType].Value: {0}",
                propertyValueDictionary[DAPropertyIds.DataType].Value);
            Console.WriteLine("propertyValueDictionary[DAPropertyId.Timestamp].Value: {0}",
                propertyValueDictionary[DAPropertyIds.Timestamp].Value);
        }
    }
}

# This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.

# 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 dictionary of property values, for all well-known properties.
try:
    propertyValueDictionary = IEasyDAClientExtension2.GetPropertyValueDictionary(client,
        '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display some of the obtained property values.
# The production code should also check for the .Exception first, before getting .Value
print('propertyValueDictionary[DAPropertyId.AccessRights].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.AccessRights)).Value, sep='')
print('propertyValueDictionary[DAPropertyId.DataType].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.DataType)).Value, sep='')
print('propertyValueDictionary[DAPropertyId.Timestamp].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.Timestamp)).Value, sep='')

print('Finished.')

' This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.

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

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

            ' Get dictionary of property values, for all well-known properties
            Dim propertyValueDictionary As DAPropertyValueDictionary
            Try
                propertyValueDictionary = client.GetPropertyValueDictionary("", "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
            ' The production code should also check for the .Exception first, before getting .Value
            Console.WriteLine("propertyValueDictionary[DAPropertyId.AccessRights].Value: {0}", propertyValueDictionary(DAPropertyIds.AccessRights).Value)
            Console.WriteLine("propertyValueDictionary[DAPropertyId.DataType].Value: {0}", propertyValueDictionary(DAPropertyIds.DataType).Value)
            Console.WriteLine("propertyValueDictionary[DAPropertyId.Timestamp].Value: {0}", propertyValueDictionary(DAPropertyIds.Timestamp).Value)
        End Sub
    End Class
End Namespace

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

Send Documentation Feedback. Resources: Knowledge Base. Technical support: Online Forums, FAQ.