Public Sub txt_ReadData(ByVal txt As TextBox, ByVal sDataFile As String, _
      Optional ByVal bAppend As Boolean = False)
        Programmpfad = My.Settings.Programmpfad & "\" & txtnr.Text & ".ttt"
 
        If System.IO.File.Exists(Programmpfad) = False Then
            MessageBox.Show("Datei ist nicht vorhanden!", "Achtung", _
              MessageBoxButtons.OK)
        Else
 
            Dim bItem As Byte
            Dim sLine As String
            Dim cZeichen As Char
 
            Dim SR As StreamReader
            SR = New StreamReader(Programmpfad)
 
            'Datei lesen bis zum Ende
            Do Until SR.EndOfStream = True
                sLine = SR.ReadLine()
 
                For Each cZeichen In sLine
                    bItem = Asc(cZeichen)
 
                    SerialPort1.BaseStream.WriteByte(bItem)
                Next
                SerialPort1.Write(vbLf)
            Loop
 
            SR.Close()
 
            stalbl.Text = "Warte auf Daten"
 
        End If
    End Sub

fg viperbone