PLCcom Opc Ua Sdk

...
'create a new subscription'
Dim subscription As Subscription = New Subscription()
subscription.PublishingInterval = 1000
subscription.PublishingEnabled = False
subscription.DisplayName = "mySubsription"
  
'register subscription events'
AddHandler subscription.StateChanged, AddressOf Subscription_StateChanged
AddHandler subscription.PublishStatusChanged, AddressOf Subscription_PublishStatusChanged
  
'add new subscription to client'
client.AddSubscription(subscription)
  
'Create a monitoring item and add to the subscription'
Dim nodeId As NodeId = client.GetNodeIdByPath("Objects.Data.Dynamic.Scalar.Int64Value")
Dim monitoredItem As MonitoredItem = New MonitoredItem(subscription.DefaultItem) With {
                                    .StartNodeId = nodeId,
                                    .SamplingInterval = 500,
                                    .QueueSize = UInteger.MaxValue,
                                    .DisplayName = nodeId.ToString()
                                }
  
'register monitoring event'
AddHandler monitoredItem.Notification, AddressOf Client_MonitorNotification
  
'add Item to subscription'
subscription.AddItem(monitoredItem)
  
'apply changes'
subscription.ApplyChanges()
  
...
  
Private Sub Client_MonitorNotification(ByVal monitoredItem As MonitoredItem, ByVal e As MonitoredItemNotificationEventArgs)
    Dim notification As MonitoredItemNotification = TryCast(e.NotificationValue, MonitoredItemNotification)
    'notifications coming here, do what you want
End Sub

...
//create and register monitoring item
//step 1 create the request list
List requests = new ArrayList();
 
//step 2 create and add a create request for a monitoring item
ReadValueId readValueId = new ReadValueId(
                                myClient.getNodeIdByPath("Objects.Server.Data.Dynamic.Scalar.Int32Value"),
                                UaAttributes.Value.getValue(), null, null);
requests.add(new MonitoredItemCreateRequest(readValueId, MonitoringMode.Reporting, new MonitoringParameters()));
 
//step3 create and add a subscription
UaSubscription subscription = myClient.getSubscriptionManager().createSubscription();
                         
//final step create, monitoring items and add monitoring item event listener
List monitoredItems = subscription.createMonitoredItems(requests, new MonitoredItemNotificationListener() {
                         
    @Override
    public void onValueNotification(MonitoredItem monitoredItem, DataValue value) {
        // value notifications coming here, do what you want
                             
    }
                         
    @Override
    public void onEventNotification(MonitoredItem monitoredItem, EventFieldList eventFieldList) {
        // event notifications coming here, do what you want
                             
    }
});