Imports System.IO.Ports
Imports System.Threading
 
Public Class Class_COM
Public Shared _serialPort As SerialPort
 
Public Function OpenCom() As Boolean 
 
  _serialPort = New SerialPort()        
  _serialPort.PortName = "COM2"
  _serialPort.BaudRate = 115200
  _serialPort.Parity = 0
  _serialPort.DataBits = 8
  _serialPort.StopBits = 1
  _serialPort.RtsEnable = True
  _serialPort.DtrEnable = True
  _serialPort.Handshake = 0
  _serialPort.ReadTimeout = 500         
  _serialPort.WriteTimeout = 500
 
  AddHandler _serialPort.DataReceived, AddressOf DataReceivedHandler
 
        Try
            _serialPort.Open()
        Catch ex As Exception
            MsgBox("Comport " & Form1.Comport & " konnte nicht geöffnet werden")
            Return 0
        End Try
 
        If _serialPort.IsOpen Then
            Form1.TextBox2.Text = "open"
            Return True
        Else
            Return 0
        End If
 
End Function
 
    Public Sub WriteCom(message)
        _serialPort.WriteLine(message)
    End Sub
 
    Public Function CloseCom() As Boolean
        _serialPort.Close()
        Form1.TextBox2.Text = "closed"
    End Function
 
    Public Function comstatus() As Boolean
        Return _serialPort.IsOpen
    End Function
 
    Private Shared Sub DataReceivedHandler(sender As Object, e As _
      SerialDataReceivedEventArgs)
        Dim sp As SerialPort = CType(sender, SerialPort)
        Dim indata As String = sp.ReadExisting()
        Console.Write("RX: ")
        Console.WriteLine(indata)
        Form1.TextBox2.Text = "123"
    End Sub
 
End Class