Implicit Type Conversion(UADataChangeFilter,Double) Operator

Converts a double to a data change filter, by creating a filter with absolute deadband.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<NotNullAttribute()>
Overloads Public Operator Widening CType( _
   ByVal absoluteDeadbandValue As Double _
) As UADataChangeFilter

'Usage

[NotNull()]
public UADataChangeFilter operator implicit( 
   double absoluteDeadbandValue
)

[NotNull()]
public:
operator UADataChangeFilter^ ( 
   double absoluteDeadbandValue
)

Parameters

absoluteDeadbandValue: A data change filter's absolute deadband value.

Return Value

Returns a data change filter specifying the given absolute deadband, and triggered by UADataChangeTrigger.StatusValueTimestamp.

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

Remarks

This operator is equivalent to FromDouble.

Example

CSharp
VB.NET
Python

// This example shows how to subscribe to changes of a monitored item with absolute deadband.
//
// 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.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class SubscribeDataChange
    {
        public static void AbsoluteDeadband()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            // Instantiate the client object and hook events
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification_AbsoluteDeadband;

            const double absoluteDeadband = 50;
            Console.WriteLine($"Subscribing with absolute deadband {absoluteDeadband}...");
            // The UADataChangeFilter has an implicit conversion from Double, which creates a filter with the specified
            // absolute deadband.
            client.SubscribeDataChange(endpointDescriptor, 
                "nsu=http://test.org/UA/Data/ ;i=11194",    // /Data.Dynamic.AnalogScalar.Int32Value
                samplingInterval:1000, 
                dataChangeFilter: absoluteDeadband);

            Console.WriteLine("Processing data change events for 20 seconds...");
            System.Threading.Thread.Sleep(20 * 1000);

            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeAllMonitoredItems();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);
        }

        static void client_DataChangeNotification_AbsoluteDeadband(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Display value
            if (e.Succeeded)
                Console.WriteLine("Value: {0}", e.AttributeData.Value);
            else
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief);
        }
    }
}

' This example shows how to subscribe to changes of a monitored item with absolute deadband.
'
' 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.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Partial Friend Class SubscribeDataChange
        Public Shared Sub AbsoluteDeadband()

            ' Define which server we will work with.
            Dim endpointDescriptor As UAEndpointDescriptor =
                    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
            ' or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            ' or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            ' Instantiate the client object and hook events
            Dim client = New EasyUAClient()
            AddHandler client.DataChangeNotification, AddressOf client_DataChangeNotification_AbsoluteDeadband

            Const absoluteDeadband As Double = 50
            Console.WriteLine("Subscribing with absolute deadband {0}...", absoluteDeadband)
            ' The UADataChangeFilter has an implicit conversion from Double, which creates a filter with the specified
            ' absolute deadband.
            client.SubscribeDataChange(endpointDescriptor,
                "nsu=http://test.org/UA/Data/ ;i=11194",    ' /Data.Dynamic.AnalogScalar.Int32Value
                samplingInterval:=1000,
                dataChangeFilter:=absoluteDeadband)

            Console.WriteLine("Processing data change events for 20 seconds...")
            Threading.Thread.Sleep(20 * 1000)

            Console.WriteLine("Unsubscribing...")
            client.UnsubscribeAllMonitoredItems()

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)
        End Sub

        Private Shared Sub client_DataChangeNotification_AbsoluteDeadband(ByVal sender As Object, ByVal e As EasyUADataChangeNotificationEventArgs)
            ' Display value
            If e.Succeeded Then
                Console.WriteLine("Value: {0}", e.AttributeData.Value)
            Else
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief)
            End If
        End Sub
    End Class
End Namespace

# This example shows how to subscribe to changes of a monitored item with absolute deadband.
#
# 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 time

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


def dataChangeNotification(sender, e):
    # Display value.
    if e.Succeeded:
        print('Value: ', e.AttributeData.Value, sep='')
    else:
        print('*** Failure: ', e.ErrorMessageBrief, sep='')


endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'

# Instantiate the client object and hook events.
client = EasyUAClient()
client.DataChangeNotification += dataChangeNotification

ABSOLUTE_DEADBAND = 50
print('Subscribing with absolute deadband ', ABSOLUTE_DEADBAND, '...', sep='')
IEasyUAClientExtension.SubscribeDataChange(client,
    endpointDescriptor,
    UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=11194'),
    1000,   # samplingInterval
    UADataChangeFilter(ABSOLUTE_DEADBAND))

print('Processing data change events for 20 seconds...')
time.sleep(20)

print('Unsubscribing...')
client.UnsubscribeAllMonitoredItems()

print('Waiting for 5 seconds...')
time.sleep(5)

print('Finished.')

CSharp
VB.NET
Python

// This example shows how to subscribe to changes of multiple monitored items with absolute deadband.
//
// 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.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class SubscribeMultipleMonitoredItems
    {
        public static void AbsoluteDeadband()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            // Instantiate the client object and hook events
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification_AbsoluteDeadband;

            Console.WriteLine("Subscribing with different absolute deadbands...");
            // The UADataChangeFilter has an implicit conversion from Double, which creates a filter with the specified
            // absolute deadband.
            client.SubscribeMultipleMonitoredItems(new[]
                {
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=11194",    // /Data.Dynamic.AnalogScalar.Int32Value
                        new UAMonitoringParameters(samplingInterval:100, dataChangeFilter:50)),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=11218",    // /Data.Dynamic.AnalogScalar.FloatValue
                        new UAMonitoringParameters(samplingInterval:100, dataChangeFilter:20))
                });

            Console.WriteLine("Processing monitored item changed events for 10 seconds...");
            System.Threading.Thread.Sleep(10 * 1000);

            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeAllMonitoredItems();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);
        }

        static void client_DataChangeNotification_AbsoluteDeadband(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Display value
            if (e.Succeeded)
                Console.WriteLine("{0}: {1}", e.Arguments.NodeDescriptor, e.AttributeData.Value);
            else
                Console.WriteLine("{0} *** Failure: {1}", e.Arguments.NodeDescriptor, e.ErrorMessageBrief);
        }
    }
}

' This example shows how to subscribe to changes of multiple monitored items with absolute deadband.
'
' 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.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Partial Friend Class SubscribeMultipleMonitoredItems
        Public Shared Sub AbsoluteDeadband()

            ' Define which server we will work with.
            Dim endpointDescriptor As UAEndpointDescriptor =
                    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
            ' or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            ' or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            ' Instantiate the client object and hook events
            Dim client = New EasyUAClient()
            AddHandler client.DataChangeNotification, AddressOf client_DataChangeNotification_AbsoluteDeadband

            Console.WriteLine("Subscribing with different absolute deadbands...")
            ' The UADataChangeFilter has an implicit conversion from Double, which creates a filter with the specified
            ' absolute deadband.
            client.SubscribeMultipleMonitoredItems(New EasyUAMonitoredItemArguments() _
                {
                    New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=11194",    ' /Data.Dynamic.AnalogScalar.Int32Value
                        New UAMonitoringParameters(samplingInterval:=100, dataChangeFilter:=50)),
                    New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=11218",    ' /Data.Dynamic.AnalogScalar.FloatValue
                        New UAMonitoringParameters(samplingInterval:=100, dataChangeFilter:=20))
                }
             )

            Console.WriteLine("Processing monitored item changed events for 10 seconds...")
            Threading.Thread.Sleep(10 * 1000)

            Console.WriteLine("Unsubscribing...")
            client.UnsubscribeAllMonitoredItems()

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)
        End Sub

        Private Shared Sub client_DataChangeNotification_AbsoluteDeadband(ByVal sender As Object, ByVal e As EasyUADataChangeNotificationEventArgs)
            ' Display value
            If e.Succeeded Then
                Console.WriteLine("{0}: {1}", e.Arguments.NodeDescriptor, e.AttributeData.Value)
            Else
                Console.WriteLine("{0} *** Failure: {1}", e.Arguments.NodeDescriptor, e.ErrorMessageBrief)
            End If
        End Sub
    End Class
End Namespace

# This example shows how to subscribe to changes of multiple monitored items with absolute deadband.
#
# 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 time

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


def dataChangeNotification(sender, e):
    # Display value.
    if e.Succeeded:
        print(e.Arguments.NodeDescriptor, ': ', e.AttributeData.Value, sep='')
    else:
        print(e.Arguments.NodeDescriptor, ' *** Failure: ', e.ErrorMessageBrief, sep='')


endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'

# Instantiate the client object and hook events.
client = EasyUAClient()
client.DataChangeNotification += dataChangeNotification

print('Subscribing with different absolute deadbands...')
client.SubscribeMultipleMonitoredItems([
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=11194'),
        UAMonitoringParameters(100, UADataChangeFilter(50))),   # samplingInterval, dataChangeFilter
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=11218'),
        UAMonitoringParameters(100, UADataChangeFilter(20))),   # samplingInterval, dataChangeFilter
    ])

print('Processing data change events for 10 seconds...')
time.sleep(10)

print('Unsubscribing...')
client.UnsubscribeAllMonitoredItems()

print('Waiting for 5 seconds...')
time.sleep(5)

print('Finished.')

CSharp

// Shows how to observe OPC UA data changes with a specified absolute deadband.
//
// 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 OpcLabs.EasyOpc.UA.Reactive;
using System;
using System.Threading;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace ReactiveDocExamples
{
    namespace _UADataChangeNotificationObservable
    {
        partial class Subscribe
        {
            public static void AbsoluteDeadband()
            {
                // Define which server we will work with.
                UAEndpointDescriptor endpointDescriptor =
                    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
                // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
                // or "https://opcua.demo-this.com:51212/UA/SampleServer/"

                const double absoluteDeadband = 50;
                Console.WriteLine($"Creating observable with absolute deadband {absoluteDeadband}...");
                var attributeArguments = new UAAttributeArguments(
                    endpointDescriptor,
                    "nsu=http://test.org/UA/Data/ ;i=11194");    // /Data.Dynamic.AnalogScalar.Int32Value
                var monitoredItemArguments = new UAMonitoredItemArguments(
                    attributeArguments,
                    new UAMonitoringParameters(samplingInterval: 1000, dataChangeFilter: absoluteDeadband));
                UADataChangeNotificationObservable<int> observable =
                    UADataChangeNotificationObservable.Create<int>(monitoredItemArguments);

                Console.WriteLine("Subscribing...");
                using (observable.Subscribe(e => Console.WriteLine(
                    (e.Exception is null) ? e.AttributeData.ToString() : e.Exception.GetBaseException().ToString())))
                {
                    Console.WriteLine("Waiting for 10 seconds...");
                    Thread.Sleep(10*1000);

                    Console.WriteLine("Unsubscribing...");
                }

                Console.WriteLine("Waiting for 2 seconds...");
                Thread.Sleep(2 * 1000);
            }
        }
    }
}

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

UADataChangeFilter Class
UADataChangeFilter Members
Overload List

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