Public Function getDefaultConfig(ByVal PortIndex As Integer) As COMMCONFIG
        ' create commconfig instance and set size 
        Dim conf As New COMMCONFIG
        conf.dcbx = New DCB
        conf.dwSize = System.Runtime.InteropServices.Marshal.SizeOf(conf)
        ' getcommconfig
        If Not GetDefaultCommConfig("COM" & PortIndex.ToString, conf, _
          conf.dwSize) = 0 Then
            Return conf
        End If
        Return Nothing
    End Function
 
    Public Structure COMMCONFIG
        Dim dwSize As Integer
        Private wVersion As Short
        Private wReserved As Short
        Dim dcbx As DCB
        Private dwProviderSubType As Integer
        Private dwProviderOffset As Integer
        Private dwProviderSize As Integer
        Private wcProviderData As Byte
    End Structure
 
    Public Structure DCB
        Dim DCBlength As Integer
        Dim BaudRate As Integer
        Dim fBitFields As Integer 'See Comments Win32API.Txt
        Private wReserved As Short
        Dim XonLim As Short
        Dim XoffLim As Short
        Dim ByteSize As Byte
        Dim Parity As Byte
        Dim StopBits As Byte
        Dim XonChar As Byte
        Dim XoffChar As Byte
        Dim ErrorChar As Byte
        Dim EofChar As Byte
        Dim EvtChar As Byte
        Private wReserved1 As Short 'Reserved - Do Not Use
    End Structure
 
 
' und btw so kansu den comport lesen und schreiben falls des unterstützt wird 
' vom device
  Public Function getAsyncCommFileStream(ByVal PortIndex As Integer, Optional _
    ByVal bufsize As Integer = 512, Optional ByVal access As IO.FileAccess = _
    IO.FileAccess.ReadWrite, Optional ByVal share As IO.FileShare = _
    IO.FileShare.ReadWrite) As IO.FileStream
        Return New IO.FileStream(CreateFile("\\.\COM" & PortIndex.ToString, _
        access, share, 0, IO.FileMode.Create, FILE_FLAG_OVERLAPPED Or _
        FILE_FLAG_NO_BUFFERING, IntPtr.Zero), IO.FileAccess.ReadWrite, True, _
        bufsize, True)
    End Function