Dim buf As Byte
    Private TextboxAktualisieren As New DelegateSub(AddressOf Wertübergabe)
 
 
    Private Sub SerialPort_DataReceived(ByVal sender As Object, ByVal e As _
      System.IO.Ports.SerialDataReceivedEventArgs) Handles _
      SerialPort.DataReceived
        For i As Integer = 0 To SerialPort.BytesToRead   ' Alle Bytes einzel 
        ' lesen und anzeigen
            Try
                Dim buf As Byte() = {SerialPort.BaseStream.ReadByte}
                Me.Invoke(TextboxAktualisieren)
 
            Catch ex As Exception
                MessageBox.Show("Ein Übertragungsfehler ist aufgetreten.", _
                  "Fehler", MessageBoxButtons.OK)
            End Try
        Next i
 
    End Sub
 
 
    Public Sub NamenStart()
        With SerialPort
            Dim FomTest As Byte() = {85, 32, 5, 21, 0} 'HEX 0x55 0x20 0x05 0x15 
            ' 0x00
 
            If .IsOpen Then
                .BaseStream.Write(FomTest, 0, 5)
                Return
            Else
                MsgBox(InfoPortClosed + .PortName, MsgBoxStyle.Critical)
            End If
        End With
    End Sub
 
 
 
    Private Sub Wertübergabe()
        TextBox1.AppendText(buf)
    End Sub