Public Class Form1
    Dim Wert As String
 
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles Me.Load
 
        SerialPort1.Open()
 
    End Sub
 
    Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As _
      System.IO.Ports.SerialDataReceivedEventArgs) Handles _
      SerialPort1.DataReceived
 
        Wert = SerialPort1.ReadLine()
        Wert = Wert.Replace(Chr(13), Nothing) 'Hier wir nur ein Zeichen(Ascii 
        ' 13) unterdrückt!
 
    End Sub
 
    Private Sub Test(ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles Button1.Click
 
        TextBox1.Text = Wert
 
    End Sub
End Class

Gruß
Christoph