Private Sub BtnZwei_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles BtnZwei.Click
        ok = False
        SerialPort1.Write("U6" & vbCr)
 
    End Sub
 
 
    Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As _
      System.IO.Ports.SerialDataReceivedEventArgs) Handles _
      SerialPort1.DataReceived
 
        s = SerialPort1.ReadTo(Chr(13))
 
        Invoke(Empfang)
 
    End Sub
 
    Private Sub InListeEintragen()
 
        ListBox1.Items.Add(s)
        If ok = False Then
            SendZwei()
        End If
 
    End Sub
 
    Private Sub SendZwei()
        Dim Text() As String, j As Boolean = True
 
        s = s.Replace("   ", " ")
        s = s.Replace("  ", " ")
        s = s.Trim(Chr(10), CChar(" "))
        Text = s.Split(" "c)
 
        Select Case Text(0)
            Case "u6"
                SerialPort1.Write("U4" & vbCr)
                ok = True
        End Select
    End Sub

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