Creazione OPC server per comunicazione con PLC Siemens

[khris81]

Ciao a tutti,

 

devo gestire 6 plc tramite kepserver, già configurati dal una ditta esterna.

Il mio compito è quello di creare un programma in vb .net per lettura/Scirttura tag del kepserver.

Riesco ad effettuare la connessione, il browsing dei tag presenti sul server e la creazione dei relativi itam lato client.

questo è il mio codice vb:

 

Public Class Form1
    Dim ConnectedServerName As String = “Kepware.KEPServerEX.V5”
    Dim ConnectedServerIP As String = "192.168.0.xxx"
    Dim OPCGroupName As String = "Gruppo1"

    Dim WithEvents AnOPCServer As OPCAutomation.OPCServer
    Dim WithEvents ConnectedOPCServer As OPCAutomation.OPCServer
    Dim ConnectedServerGroup As OPCAutomation.OPCGroups
    Dim WithEvents ConnectedGroup As OPCAutomation.OPCGroup

    Dim OPCItemCollection As OPCAutomation.OPCItems
    Dim OPCItem As OPCAutomation.OPCItem

    Dim ItemServerHandles As System.Array
    Dim ItemServerErrors As System.Array

 

    Public WithEvents WriteItem0 As System.Windows.Forms.Button

    Dim WithEvents MyOPCBrowser As OPCAutomation.OPCBrowser

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Try
            'Create a new OPC Server object
            ConnectedOPCServer = New OPCAutomation.OPCServer

            'Attempt to connect with the server (remote in this example)
            ConnectedOPCServer.Connect(ConnectedServerName, ConnectedServerIP)

            'Prepare to add a group to the current OPC Server
            ' Get the group interface from the server object
            ConnectedServerGroup = ConnectedOPCServer.OPCGroups

            ' Set the desire active state for the group
            ConnectedServerGroup.DefaultGroupIsActive = True

            'Set the desired percent deadband - enter an integer from 0 to 100 for the deadband
            ConnectedServerGroup.DefaultGroupDeadband = 0

            ' Add the group and set its update rate - enter whatever group name you want in place of “DataGroup1”
            ConnectedGroup = ConnectedServerGroup.Add(OPCGroupName)

            ' Set the update rate for the group - enter an long integer value representing the millisecond group update rate
            ConnectedGroup.UpdateRate = 500

            ' The following line is crucial -- without it you won’t be subscribed to the server and DataChange events will not fire!    
            ConnectedGroup.IsSubscribed = True

            ' ottiene elenco tag dal server
            TagList = GetServerTag()

            ' creazione item a livello di client
            AddItem(TagList)

        Catch ex As Exception
            ' Error handling
            MessageBox.Show("OPC Connect: " + ex.Message, "OPCInterface Exception", MessageBoxButtons.OK)
        End Try
    End Sub

    Private Sub AddItem(TagList() As String)
        Try
            Dim OPCItemIDs() As String
            Dim ClientHandles() As Int32
            Dim ItemNum As Short

            ' conta il numero di tag presenti sul server
            For i As Short = 1 To TagList.Length - 1
                If TagList(i) = "" Then
                    Exit For
                End If
                ItemNum += 1
            Next i

            ReDim OPCItemIDs(ItemNum)
            ReDim ClientHandles(ItemNum)

            For i As Short = 1 To ItemNum
                If TagList(i) = "" Then
                    Exit For
                End If
                OPCItemIDs(i) = TagList(i)
                ClientHandles(i) = i
            Next i

            'Gets an items collection from the current Group
            OPCItemCollection = ConnectedGroup.OPCItems

            'Sets the items collection to active
            OPCItemCollection.DefaultIsActive = True

            'This line adds the items we’ve chosen to the items collection and in turn to the group in the OPC Server
            OPCItemCollection.AddItems(ItemNum, OPCItemIDs, ClientHandles, ItemServerHandles, ItemServerErrors)

        Catch ex As Exception
            ' Error handling
            MessageBox.Show("OPC Connect: " + ex.Message, "OPCInterface Exception", MessageBoxButtons.OK)
        End Try
    End Sub

    Private Function GetServerTag() As String()
        Try
            Dim ChannelName(999) As String
            Dim DeviceName(999) As String
            Dim TagName(999) As String
            Dim TagListServer(999) As String
            Dim i4 As Short = 0

            MyOPCBrowser = ConnectedOPCServer.CreateBrowser

            'per estrarre i soli tag di tipo integer
            MyOPCBrowser.DataType = vbInteger

            MyOPCBrowser.ShowBranches()
            For i = 1 To MyOPCBrowser.Count
                ChannelName(i) = MyOPCBrowser.Item(i)
                MyOPCBrowser.MoveDown(MyOPCBrowser.Item(i))
                MyOPCBrowser.ShowBranches()
                For i2 = 1 To MyOPCBrowser.Count
                    DeviceName(i2) = MyOPCBrowser.Item(i2)
                    MyOPCBrowser.MoveDown(MyOPCBrowser.Item(i2))
                    MyOPCBrowser.ShowLeafs()
                    For i3 = 1 To MyOPCBrowser.Count
                        TagName(i3) = MyOPCBrowser.Item(i3)
                        If TagName(i3).Substring(0, 1) = "_" Then
                            Continue For
                        End If
                        ListBox1.Items.Add(ChannelName(i) + "." + DeviceName(i2) + "." + TagName(i3))
                            i4 += 1
                        TagListServer(i4) = ChannelName(i) + "." + DeviceName(i2) + "." + TagName(i3)
                    Next i3
                    MyOPCBrowser.MoveUp()
                    MyOPCBrowser.ShowBranches()
                Next i2
                MyOPCBrowser.MoveUp()
                MyOPCBrowser.ShowBranches()
            Next i

            Return TagListServer

        Catch ex As Exception
            ' Error handling
            MessageBox.Show("OPC Connect: " + ex.Message, "OPCInterface Exception", MessageBoxButtons.OK)
        End Try
    End Function

 

 Private Sub ConnectedGroup_DataChange(TransactionID As Integer, NumItems As Integer, ByRef ClientHandles As Array, ByRef ItemValues As Array, ByRef Qualities As Array, ByRef TimeStamps As Array) Handles ConnectedGroup.DataChange
        Try
            Dim i As Integer

End sub

 

 

Il problema sono le variabili, ItemServerHandles e ItemServerErrors, che non restituiscono alcun valore, itemserverhandles dovrebbe restituire un intero che è il numero relativo al tag presente sul server e itemservererrors, il numero di errore se presente.

Di conseguenza se cambio il valore di un tag, l'evento connectedgroup_datachange si scatena, ma le variabili, ClientHandles, ItemValues, Qualities, TimeStamps, non riportano alcun valore.

 

Non capisco cosa sto sbagliando, qualcuno riesce ad aiutarmi?

 

grazie, ciao.