// This example shows how to subscribe to changes of a single monitored item, and display the value of the item with each change
// using a callback method that is provided as lambda expression.
using System;
using OpcLabs.EasyOpc.UA;
namespace UADocExamples._EasyUAClient
{
partial class SubscribeDataChange
{
public static void CallbackLambda()
{
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
var client = new EasyUAClient();
Console.WriteLine("Subscribing...");
// The callback is a lambda expression the displays the value
client.SubscribeDataChange(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000,
(sender, eventArgs) =>
{
if (eventArgs.Succeeded)
Console.WriteLine("Value: {0}", eventArgs.AttributeData.Value);
else
Console.WriteLine("*** Failure: {0}", eventArgs.ErrorMessageBrief);
});
Console.WriteLine("Processing data change events for 10 seconds...");
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Unsubscribing...");
client.UnsubscribeAllMonitoredItems();
Console.WriteLine("Waiting for 2 seconds...");
System.Threading.Thread.Sleep(2 * 1000);
}
}
}
// This example shows how to subscribe to changes of a single monitored item, and display the value of the item with each change
// using a callback method that is provided as a function delegate.
module _EasyUAClient.SubscribeDataChange
open OpcLabs.EasyOpc.UA
open System
open System.Threading
let CallbackFunction =
let endpointDescriptor =
new 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
let client = new EasyUAClient()
Console.WriteLine("Subscribing...");
// The callback is a delegate that displays the value
let handle =
client.SubscribeDataChange(
endpointDescriptor,
new UANodeDescriptor("nsu=http://test.org/UA/Data/;i=10853"),
1000,
new EasyUADataChangeNotificationEventHandler(
fun sender eventArgs ->
if eventArgs.Succeeded then Console.WriteLine("Value: {0}", eventArgs.AttributeData.Value)
else Console.WriteLine("*** Failure: {0}", eventArgs.ErrorMessageBrief)))
Console.WriteLine("Processing data change events for 10 seconds...")
Thread.Sleep(10 * 1000)
Console.WriteLine("Unsubscribing...")
client.UnsubscribeAllMonitoredItems()
Console.WriteLine("Waiting for 2 seconds...")
Thread.Sleep(2 * 1000)
' This example shows how to subscribe to changes of a single monitored item, and display the value of the item with each change
' using a callback method that is provided as lambda expression.
Imports OpcLabs.EasyOpc.UA
Namespace _EasyUAClient
Partial Friend Class SubscribeDataChange
Public Shared Sub CallbackLambda()
' 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
Dim client = New EasyUAClient()
Console.WriteLine("Subscribing...")
' The callback is a lambda expression the displays the value
client.SubscribeDataChange( _
endpointDescriptor, _
"nsu=http://test.org/UA/Data/ ;i=10853", _
1000, _
Sub(sender, eventArgs)
If eventArgs.Succeeded Then
Console.WriteLine("Value: {0}", eventArgs.AttributeData.Value)
Else
Console.WriteLine("*** Failure: {0}", eventArgs.ErrorMessageBrief)
End If
End Sub)
Console.WriteLine("Processing monitored item changed events for 10 seconds...")
Threading.Thread.Sleep(10 * 1000)
Console.WriteLine("Unsubscribing...")
client.UnsubscribeAllMonitoredItems()
Console.WriteLine("Waiting for 2 seconds...")
Threading.Thread.Sleep(2 * 1000)
End Sub
End Class
End Namespace