// This example shows how to monitor connections to and disconnections from the OPC UA server.
using System;
using Microsoft.Extensions.DependencyInjection;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;
using OpcLabs.EasyOpc.UA.Services;
namespace UADocExamples._EasyUAClientConnectionMonitoring
{
class ServerConditionChanged
{
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.
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;
}
// Hook events.
client.DataChangeNotification += client_DataChangeNotification;
clientConnectionMonitoring.ServerConditionChanged += clientConnectionMonitoring_OnServerConditionChanged;
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("Reading (2)");
// The second read, because it closely follows the first one, will reuse the connection that is already
// open.
UAAttributeData attributeData2 = client.Read(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853");
Console.WriteLine(attributeData2);
}
catch (UAException uaException)
{
Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}");
}
Console.WriteLine("Waiting for 10 seconds...");
// Since the connection is now not used for some time, it will be closed.
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Subscribing...");
// Subscribing to a monitored item will cause a connection to the server, if one is not yet open.
client.SubscribeDataChange(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000);
Console.WriteLine("Waiting for 10 seconds...");
// The connection will not be closed as long as there are any subscriptions to the server.
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Unsubscribing...");
client.UnsubscribeAllMonitoredItems();
Console.WriteLine("Waiting for 10 seconds...");
// After some delay, the connection will be closed, because there are no subscriptions to the server.
System.Threading.Thread.Sleep(10 * 1000);
Console.WriteLine("Finished.");
}
}
static void client_DataChangeNotification(object sender, EasyUADataChangeNotificationEventArgs e)
{
// Display value
if (e.Succeeded)
Console.WriteLine($"Value: {e.AttributeData.Value}");
else
Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}");
}
static void clientConnectionMonitoring_OnServerConditionChanged(object sender, EasyUAServerConditionChangedEventArgs e)
{
// Display the event
Console.WriteLine(e);
}
// Example output:
//
//Reading(1)
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
//-8.095801E+32 {System.Single} @2021-06-24T07:09:46.062 @@2021-06-24T07:09:46.062; Good
//Reading(2)
//-3.11389E-18 {System.Single} @2021 - 06 - 24T07: 09:46.125 @@2021 - 06 - 24T07: 09:46.125; 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(Infinite); Success
//Subscribing...
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connecting; Success
//Waiting for 10 seconds...
//"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer" Connected; Success
//Value: 3.293034E-31
//Value: 6.838126E+37
//Value: 5.837702E-29
//Value: 0.02940081
//Value: -9.653872E-17
//Value: -1.012749E+29
//Value: -1.422391E+20
//Value: -3.56571E-22
//Unsubscribing...
//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(Infinite); Success
//Finished.
}
}
# This example shows how to monitor connections to and disconnections from the OPC UA server.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time
# 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 *
def dataChangeNotification(sender, e):
# Display value.
if e.Succeeded:
print('Value: ', e.AttributeData.Value, sep='')
else:
print('*** Failure: ', e.ErrorMessageBrief, sep='')
def onServerConditionChanged(sender, e):
# Display the event.
print(e)
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.
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()
# Hook events
client.DataChangeNotification += dataChangeNotification
clientConnectionMonitoring.ServerConditionChanged += onServerConditionChanged
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('Reading (2)')
# The second read, because it closely follows the first one, will reuse the connection that is already
# open.
attributeData2 = IEasyUAClientExtension.Read(client,
endpointDescriptor,
UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'))
print(attributeData2)
except UAException as uaException:
print('*** Failure: ' + uaException.GetBaseException().Message)
print('Waiting for 10 seconds...')
# Since the connection is now not used for some time, it will be closed.
time.sleep(10)
print('Subscribing...')
# Subscribing to a monitored item will cause a connection to the server, if one is not yet open.
IEasyUAClientExtension.SubscribeDataChange(client,
endpointDescriptor,
UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
1000)
print('Waiting for 10 seconds...')
# The connection will not be closed as long as there are any subscriptions to the server.
time.sleep(10)
print('Unsubscribing...')
client.UnsubscribeAllMonitoredItems()
print('Waiting for 10 seconds...')
# After some delay, the connection will be closed, because there are no subscriptions to the server.
time.sleep(10)
print('Finished.')
finally:
client and client.Dispose()
