Private endpointDescriptor As UAEndpointDescriptor
    Private client As EasyUAClient
    Private HeartbeatLast As Integer = 0
    Private HeartbeatSend As Integer = 0
    Public HeartbeatCounter As Integer = 0
    Public HeartbeatTimeout As Integer = 0
 
    Dim nodeDescriptorArrayTX() As UANodeDescriptor

Public Sub RegisterNodes()
        OPClog("Register Nodes")
        OPClog(client.InstanceParameters.ToString())
        Try
            Dim clientnoderegistration As IEasyUAClientNodeRegistration = client.GetRequiredService(Of IEasyUAClientNodeRegistration)
            Dim clientConnectionControl As IEasyUAClientConnectionControl = client.GetRequiredService(Of IEasyUAClientConnectionControl)

Public Sub RegisterNodes()
        OPClog("Register Nodes")
        OPClog(client.GetType.ToString())
        Try
            Dim clientnoderegistration As IEasyUAClientNodeRegistration = client.GetRequiredService(Of IEasyUAClientNodeRegistration)
            Dim clientConnectionControl As IEasyUAClientConnectionControl = client.GetRequiredService(Of IEasyUAClientConnectionControl)

Dim nodeDescriptorArrayTX() As UANodeDescriptor
 
    'Methods
    Public Sub New(ByVal address As String, ByVal port As String)
        Me.Address = address
        Me.Port = port
    End Sub
 
    Public Sub SetClientAtributes()
        'cancel all old subscriptions
        client.UnsubscribeAllMonitoredItems()
        ' Define which server to work with.
        url = Address + ":" + Port
        endpointDescriptor = New UAEndpointDescriptor(url) '.WithAnonymousIdentity()
        ' Set the application name, which determines the subject of the client certificate.
        EasyUAClient.SharedParameters.EngineParameters.ApplicationParameters.ApplicationManifest.ApplicationName = "GfAMMS - OPC UA client"
        EasyUAClient.SharedParameters.EngineParameters.ApplicationParameters.ApplicationManifest.InstanceOwnStorePath = "C:\MMS\CertificateStores"
        EasyUAClient.SharedParameters.EngineParameters.CertificateAcceptancePolicy.TrustedEndpointUrlStrings.Add(url)
    End Sub
 
Public Sub CheckServer()
        Try
            client = New EasyUAClient()
            Dim serialNumber As Long = CUInt(client.LicenseInfo("Multipurpose.SerialNumber"))
            SetClientAtributes()
            OPClog($"{Text20}: {serialNumber}")
            OPClog(Text01)
            Dim attributeData As New UAAttributeData
            'Read
            attributeData = client.Read(endpointDescriptor, "ns=0;i=2259") '0   2259
            'Display results
            If attributeData.HasValue Then
                If Not Integer.TryParse(attributeData.Value.ToString(), ServerState) Then
                    ServerState = 7
                End If
                Select Case ServerState
                    Case 0
                        OPCconnection = True
                        OPCstateMsg(False, Text02) '"Server: running"
                        StartPLCcommunication()
                    Case 1
                        OPCconnection = False
                        OPCstateMsg(True, Text03) '"Server: failed"
                    Case 2
                        OPCconnection = False
                        OPCstateMsg(True, Text04) '"Server: no configuration"
                    Case 3
                        OPCconnection = False
                        OPCstateMsg(True, Text05) '"Server: suspended"
                    Case 4
                        OPCconnection = False
                        OPCstateMsg(True, Text06) '"Server: shutdown"
                    Case 5
                        OPCconnection = False
                        OPCstateMsg(True, Text07) '"Server: test"
                    Case 6
                        OPCconnection = False
                        OPCstateMsg(True, Text08) '"Server: communication fault"
                    Case 7
                        OPCconnection = False
                        OPCstateMsg(True, Text09) '"Server: unknown"
                End Select
            End If
        Catch uaException As UAException
            OPClog($"F01 {Text11}: {uaException.GetBaseException.Message}")
            OPCstate = Text13
            OPCstateColour = New SolidColorBrush(Color.FromRgb(249, 144, 114))
            Exit Sub
        End Try
    End Sub
 
    Public Sub StartPLCcommunication()
        OPClog(Text33) '"trying to connect to PLC..."
        'check PLC connection
        Try
            client.WriteValue(endpointDescriptor, ConfigurationManager.AppSettings.Get("opcTagPrefix") + Chr(34) + "Var" + Chr(34) + "." + Chr(34) + "EGA" + Chr(34) + "." + Chr(34) + "I_Heartbeat" + Chr(34), 1)
        Catch uaException As UAException
            OPClog(Text34) '"PLC: connection failed"
            PLCconnection = False
            Exit Sub
        End Try
        OPClog(Text35) '"PLC: connection running"
        PLCconnection = True
        If ConfigurationManager.AppSettings.Get("RecipeManagement") Then
            UpdateRecipeData()
            UpdateRecipeMaxLimits()
            UpdateRecipeMinLimits()
        End If
        'SetAllDataIntervals()   Only if MMS functionallity is activated
        RegisterNodes()
     End Sub
 
    Public Sub RegisterNodes()
        OPClog("Register Nodes")
        Try
            Dim clientnoderegistration As IEasyUAClientNodeRegistration = client.GetRequiredService(Of IEasyUAClientNodeRegistration)
etc....

Public Sub RegisterNodes()
        OPClog("Register Nodes")
        Try
            Dim clientnoderegistration As IEasyUAClientNodeRegistration = client.GetRequiredService(Of IEasyUAClientNodeRegistration)
            Dim clientConnectionControl As IEasyUAClientConnectionControl = client.GetRequiredService(Of IEasyUAClientConnectionControl)
 
            nodeDescriptorArrayTX = {
         ConfigurationManager.AppSettings.Get("opcTagPrefix") + Chr(34) + "Var" + Chr(34) + "." + Chr(34) + "EGA" + Chr(34) + "." + Chr(34) + "UWL_AB_I_Nodes_TxPDO1_L" + Chr(34) + "[0,0]." + Chr(34) + "StatusWord" + Chr(34),
 ...... etc.... 
    }
 Dim registrationHandleArray As Integer() = clientnoderegistration.RegisterMultipleNodes(endpointDescriptor, nodeDescriptorArrayTX)
 
 Dim lockHandleTX As Integer = clientConnectionControl.LockConnection(endpointDescriptor)
 
        Catch ex As Exception
            OPClog(ex.Message)
        End Try