Try
            Dim NumberOfReadedBytes As Integer = sp_serialport.BytesToRead
            For i As Integer = 1 To NumberOfReadedBytes
                tempbyte = sp_serialport.ReadByte()
                Readstring = Readstring + Chr(tempbyte)
            Next i
        Catch ex As Exception
            Errormessage = "Failed to read in the bytes !"
            Exit Sub
        End Try