Private Sub btn_senden_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles btn_senden.Click
        'Dim senden As String
 
        SerialPort1.Open()
        Dim x As Integer
        Try
            Dim tobesplitted As String = Telegramm
            Dim liste As New List(Of String)
            For I = 0 To tobesplitted.Length - 1 Step 2
                liste.Add(tobesplitted.Substring(I, 2))
            Next I
 
            For x = 0 To Telegramm.Length
                SerialPort1.Write(liste(x)) '(Convert.ToString(Telegramm(x) & 
                ' Telegramm(x + 1))) ' convert byte geht nicht - Fehler
            Next x
            'MessageBox.Show(Telegramm(0))
        Catch ex As Exception
            MsgBox("Fehler ....")
        End Try
 
        SerialPort1.Close()
 
    End Sub
    'Private Function ConvertAsciiHexToByte(ByVal asciiHexToConvert As String) 
    ' As Byte
 
    '    Dim convertedValue As Byte
 
    '    convertedValue = Convert.ToByte(asciiHexToConvert, 16)
    '    Return convertedValue
 
    'End Function
 
    'Private Function ConvertByteToAsciiHex(ByVal byteToConvert As Byte) As 
    ' String
 
    '    Dim convertedValue As String
 
    '    convertedValue = Hex$(byteToConvert)
    '    Return convertedValue
 
    'End Function
End Class