// This example shows how to lock and unlock connections to an OPC UA server. The component attempts to keep the locked
// connections open, until unlocked.
//
// 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 Microsoft.Extensions.DependencyInjection;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;
using OpcLabs.EasyOpc.UA.Services;
namespace UADocExamples._EasyUAClientConnectionControl
{
class LockAndUnlockConnection
{
public static void Main1()
{
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
using (var client = new EasyUAClient())
{
// Obtain the client connection monitoring service.
IEasyUAClientConnectionMonitoring clientConnectionMonitoring = client.GetService<IEasyUAClientConnectionMonitoring>();
if (clientConnectionMonitoring is null)
{
Console.WriteLine("The client connection monitoring service is not available.");
return;
}
// Obtain the client connection control service.
IEasyUAClientConnectionControl clientConnectionControl = client.GetService<IEasyUAClientConnectionControl>();
if (clientConnectionControl is null)
{
Console.WriteLine("The client connection control service is not available.");
return;
}
// Display the server condition changed events.
clientConnectionMonitoring.ServerConditionChanged += (sender, args) => Console.WriteLine(args);
int lockHandle = 0;
bool locked = false;
try
{
Console.WriteLine("Reading (1)");
// The first read will cause a connection to the server.
UAAttributeData attributeData1 =
client.Read(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853");
Console.WriteLine(attributeData1);
Console.WriteLine("Waiting for 10 seconds...");
// Since the connection is now not used for some time, and it is not locked, it will be closed.
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Locking");
// Locking the connection causes it to open, if possible.
lockHandle = clientConnectionControl.LockConnection(endpointDescriptor);
locked = true;
Console.WriteLine("Waiting for 10 seconds...");
// The connection is locked, it will not be closed now.
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Reading (2)");
UAAttributeData attributeData2 =
client.Read(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853");
Console.WriteLine(attributeData2);
Console.WriteLine("Waiting for 10 seconds...");
// The connection is still locked, it will not be closed now.
System.Threading.Thread.Sleep(10 * 1000);
}
catch (UAException uaException)
{
Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
}
finally
{
if (locked)
{
Console.WriteLine("Unlocking");
clientConnectionControl.UnlockConnection(lockHandle);
}
}
Console.WriteLine("Waiting for 10 seconds...");
// After some delay, the connection will be closed, because there are no subscriptions to the server and no
// connection locks.
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Finished.");
}
}
// Example output:
//
//Reading (1)
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success; Attempt #1
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
//-1.034588E+18 {Single} @2021-11-15T15:26:39.169 @@2021-11-15T15:26:39.169; Good
//Waiting for 10 seconds...
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnecting; Success
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnected(RetrialDelay=Infinite); Success
//Locking
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success; Attempt #1
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
//Waiting for 10 seconds...
//Reading (2)
//2.288872E+21 {Single} @2021-11-15T15:26:59.836 @@2021-11-15T15:26:59.836; Good
//Waiting for 10 seconds...
//Unlocking
//Waiting for 10 seconds...
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnecting; Success
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnected(RetrialDelay=Infinite); Success
//Finished.
}
}
' This example shows how to lock and unlock connections to an OPC UA server. The component attempts to keep the locked
' connections open, until unlocked.
'
' 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 Microsoft.Extensions.DependencyInjection
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.OperationModel
Imports OpcLabs.EasyOpc.UA.Services
Namespace _EasyUAClientConnectionControl
Partial Friend Class LockAndUnlockConnection
Public Shared Sub Main1()
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
Using client = New EasyUAClient()
' Obtain the client connection monitoring service.
Dim clientConnectionMonitoring As IEasyUAClientConnectionMonitoring = client.GetService(Of IEasyUAClientConnectionMonitoring)
If clientConnectionMonitoring Is Nothing Then
Console.WriteLine("The client connection monitoring service is not available.")
Exit Sub
End If
' Obtain the client connection control service.
Dim clientConnectionControl As IEasyUAClientConnectionControl = client.GetService(Of IEasyUAClientConnectionControl)
If clientConnectionControl Is Nothing Then
Console.WriteLine("The client connection control service is not available.")
Exit Sub
End If
' Display the server condition changed events.
AddHandler clientConnectionMonitoring.ServerConditionChanged, Sub(sender, args)
Console.WriteLine(args)
End Sub
Dim lockHandle As Integer = 0
Dim locked As Boolean = False
Try
Console.WriteLine("Reading (1)")
' The first read will cause a connection to the server.
Dim attributeData1 As UAAttributeData =
client.Read(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853")
Console.WriteLine(attributeData1)
Console.WriteLine("Waiting for 10 seconds...")
' Since the connection is now not used for some time, and it is not locked, it will be closed.
System.Threading.Thread.Sleep(10 * 1000)
Console.WriteLine("Locking")
' Locking the connection causes it to open, if possible.
lockHandle = clientConnectionControl.LockConnection(endpointDescriptor)
locked = True
Console.WriteLine("Waiting for 10 seconds...")
' The connection is locked, it will not be closed now.
System.Threading.Thread.Sleep(10 * 1000)
Console.WriteLine("Reading (2)")
Dim attributeData2 As UAAttributeData =
client.Read(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853")
Console.WriteLine(attributeData2)
Console.WriteLine("Waiting for 10 seconds...")
' The connection is still locked, it will not be closed now.
System.Threading.Thread.Sleep(10 * 1000)
Catch uaException As UAException
Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message)
Finally
If locked Then
Console.WriteLine("Unlocking")
clientConnectionControl.UnlockConnection(lockHandle)
End If
End Try
Console.WriteLine("Waiting for 10 seconds...")
' After some delay, the connection will be closed, because there are no subscriptions to the server and no
' connection locks.
System.Threading.Thread.Sleep(10 * 1000)
Console.WriteLine("Finished.")
End Using
End Sub
' Example output
'
'Reading (1)
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success; Attempt #1
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
'-1.034588E+18 {Single} @2021-11-15T15:26:39.169 @@2021-11-15T15:26:39.169; Good
'Waiting for 10 seconds...
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnecting; Success
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnected(RetrialDelay=Infinite); Success
'Locking
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success; Attempt #1
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
'Waiting for 10 seconds...
'Reading (2)
'2.288872E+21 {Single} @2021-11-15T15:26:59.836 @@2021-11-15T15:26:59.836; Good
'Waiting for 10 seconds...
'Unlocking
'Waiting for 10 seconds...
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnecting; Success
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnected(RetrialDelay=Infinite); Success
'Finished.
End Class
End Namespace
Rem This example shows how to lock and unlock connections to an OPC UA server. The component attempts to keep the locked
Rem connections open, until unlocked.
Rem
Rem Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
Rem OPC client and subscriber examples in VBScript on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBScript .
Rem Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
Rem a commercial license in order to use Online Forums, and we reply to every post.
Option Explicit
Dim endpointDescriptorUrlString: endpointDescriptorUrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
Dim EndpointDescriptor: Set EndpointDescriptor = CreateObject("OpcLabs.EasyOpc.UA.UAEndpointDescriptor")
EndpointDescriptor.UrlString = endpointDescriptorUrlString
' Instantiate the client object.
Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.UA.EasyUAClient")
' Obtain the client connection monitoring service.
Dim ClientConnectionMonitoring: Set ClientConnectionMonitoring = Client.GetServiceByName("OpcLabs.EasyOpc.UA.Services.IEasyUAClientConnectionMonitoring, OpcLabs.EasyOpcUA")
If ClientConnectionMonitoring Is Nothing Then
WScript.Echo "The client connection monitoring service is not available."
WScript.Quit
End If
' Obtain the client connection control service.
Dim ClientConnectionControl: Set ClientConnectionControl = Client.GetServiceByName("OpcLabs.EasyOpc.UA.Services.IEasyUAClientConnectionControl, OpcLabs.EasyOpcUA")
If ClientConnectionControl Is Nothing Then
WScript.Echo "The client connection control service is not available."
WScript.Quit
End If
' Display the server condition changed events.
WScript.ConnectObject ClientConnectionMonitoring, "ClientConnectionMonitoring_"
WScript.Echo "Reading (1)"
' The first read will cause a connection to the server.
Dim AttributeData1: Set AttributeData1 = Client.Read(endpointDescriptorUrlString, "nsu=http://test.org/UA/Data/ ;i=10853")
WScript.Echo AttributeData1
WScript.Echo "Waiting for 10 seconds..."
' Since the connection is now not used for some time, and it is not locked, it will be closed.
WScript.Sleep 10*1000
WScript.Echo "Locking..."
' Locking the connection causes it to open, if possible.
Dim lockHandle: lockHandle = ClientConnectionControl.LockConnection(EndpointDescriptor)
WScript.Echo "Waiting for 10 seconds..."
' The connection is locked, it will not be closed now.
WScript.Sleep 10*1000
WScript.Echo "Reading (2)"
' The second read, because it closely follows the first one, will reuse the connection that is already open.
Dim AttributeData2: Set AttributeData2 = Client.Read(endpointDescriptorUrlString, "nsu=http://test.org/UA/Data/ ;i=10853")
WScript.Echo AttributeData2
WScript.Echo "Waiting for 10 seconds..."
' The connection is still locked, it will not be closed now.
WScript.Sleep 10*1000
WScript.Echo "Unlocking..."
ClientConnectionControl.UnlockConnection(lockHandle)
WScript.Echo "Waiting for 10 seconds..."
' After some delay, the connection will be closed, because there are no subscriptions to the server and no
' connection locks.
WScript.Sleep 10*1000
WScript.Echo "Finished."
Sub ClientConnectionMonitoring_ServerConditionChanged(Sender, e)
WScript.Echo e
End Sub
' Example output:
'
'Reading (1)
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success; Attempt #1
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
'-1.034588E+18 {Single} @2021-11-15T15:26:39.169 @@2021-11-15T15:26:39.169; Good
'Waiting for 10 seconds...
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnecting; Success
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnected(RetrialDelay=Infinite); Success
'Locking
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success; Attempt #1
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
'Waiting for 10 seconds...
'Reading (2)
'2.288872E+21 {Single} @2021-11-15T15:26:59.836 @@2021-11-15T15:26:59.836; Good
'Waiting for 10 seconds...
'Unlocking
'Waiting for 10 seconds...
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnecting; Success
'"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Disconnected(RetrialDelay=Infinite); Success
'Finished.
# This example shows how to lock and unlock connections to an OPC UA server. The component attempts to keep the locked
# connections open, until unlocked.
#
# 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 time
import opclabs_quickopc
# Import .NET namespaces.
from Microsoft.Extensions.DependencyInjection import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *
from OpcLabs.EasyOpc.UA.Services import *
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 = None
try:
client = EasyUAClient()
# Obtain the client connection monitoring service.
clientConnectionMonitoring = ServiceProviderServiceExtensions.GetService[IEasyUAClientConnectionMonitoring](client)
if clientConnectionMonitoring is None:
print('The client connection monitoring service is not available.')
exit()
# Obtain the client connection control service.
clientConnectionControl = ServiceProviderServiceExtensions.GetService[IEasyUAClientConnectionControl](client)
if clientConnectionControl is None:
print('The client connection control service is not available.')
exit()
# Display the server condition changed events.
clientConnectionMonitoring.ServerConditionChanged += lambda sender, args: print(args)
lockHandle = 0
locked = False
try:
print('Reading (1)')
# The first read will cause a connection to the server.
attributeData1 = IEasyUAClientExtension.Read(client,
endpointDescriptor,
UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'))
print(attributeData1)
print('Waiting for 10 seconds...')
# Since the connection is now not used for some time, and it is not locked, it will be closed.
time.sleep(10)
print('Locking')
# Locking the connection causes it to open, if possible.
lockHandle = clientConnectionControl.LockConnection(endpointDescriptor)
locked = True
print('Waiting for 10 seconds...')
# The connection is locked, it will not be closed now.
time.sleep(10)
print('Reading (2)')
attributeData2 = IEasyUAClientExtension.Read(client,
endpointDescriptor,
UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'))
print(attributeData2)
print('Waiting for 10 seconds...')
# The connection is still locked, it will not be closed now.
time.sleep(10)
except UAException as uaException:
print('*** Failure: ' + uaException.GetBaseException().Message)
finally:
if locked:
print('Unlocking')
clientConnectionControl.UnlockConnection(lockHandle)
print('Waiting for 10 seconds...')
# After some delay, the connection will be closed, because there are no subscriptions to the server and no
# connection locks.
time.sleep(10)
print('Finished.')
finally:
client and client.Dispose()