Const cDataSeries2 As String = "DataSeries2"
 
    Public Structure strucChartData
        Dim time As Date
        Dim value1 As Double
        Dim value2 As Double
    End Structure

   MyBase.Series.Add(cDataSeries2)
   With MyBase.Series(cDataSeries2)
       .ChartType = Charting.SeriesChartType.Line 
       .BorderWidth = 2
   End With

Public Function AddDataPoint(ByVal vl1 As Double, _
    ByVal vl2 As Double) As Boolean
 
    If Not _Initialized Then Return False
    If Double.IsNaN(vl1) OrElse Double.IsInfinity(vl1) Then Return False
    If Double.IsNaN(vl2) OrElse Double.IsInfinity(vl2) Then Return False
 
    Dim ivl1 As Double = vl1, ivl2 As Double = vl2
    'Ausreisser-Werte "einfangen"
    ivl1 = Math.Min(ivl1, MyBase.ChartAreas(0).AxisY.Maximum)
    ivl1 = Math.Max(ivl1, MyBase.ChartAreas(0).AxisY.Minimum)
    ivl2 = Math.Min(ivl2, MyBase.ChartAreas(0).AxisY.Maximum)
    ivl2 = Math.Max(ivl2, MyBase.ChartAreas(0).AxisY.Minimum)
 
    With MyBase.Series(cDataSeries)
       'Datenpunkt anhängen (incl. Zeitstempel)
       .Points.AddXY(DateTime.Now.Ticks - _starttime, ivl1)
       `... auch in der zweiten Serie 
       MyBase.Series(cDataSeries2).Points.AddXY _
       (DateTime.Now.Ticks - _starttime, ivl2)
       If _createdatalist Then
          DataList.Add(New strucChartData _
           With {.time = Now, .value1 = vl1, .value2 = vl2})
       End If
 
       'veraltete Punkte entfernen (beide Serien)
       While .Points.Count > _maxpoints
           .Points.RemoveAt(0)
           MyBase.Series(cDataSeries2).Points.RemoveAt(0)
       End While
 
       'X-Achse auf den aktuellen Abschnitt der Zeitlinie ausrichten
       MyBase.ChartAreas(0).AxisX.Minimum = .Points(0).XValue
       MyBase.ChartAreas(0).AxisX.Maximum = .Points(.Points.Count - 1).XValue
 
       'Hier wie oben beide Datenpunkte einrichten
       '................
     End With 
 
     'Neuzeichnen des Chart veranlassen
     Me.Invalidate()
     Return True
End Function