VB.Net Tutorial/Development/SerialPort

My.Computer.Ports.SerialPortNames

Option Strict On
Imports System.Collections.ObjectModel
Public Module PortsTest
   Public Sub Main()
      Dim ports As ReadOnlyCollection(Of String) = _
      My.ruputer.Ports.SerialPortNames
      For Each port As String In ports
         Console.WriteLine(port)
      Next
   End Sub
End Module

COM3

Write to Serial Port

Public Class Tester
    Public Shared Sub Main
    
        Dim com1Port As IO.Ports.SerialPort = Nothing
        Try
            com1Port = My.ruputer.Ports.OpenSerialPort("COM1")
            com1Port.WriteLine("serialData")
            com1Port.Write("serialData")
            com1Port.Close()
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        Finally
            If (com1Port IsNot Nothing) Then com1Port.Dispose()
            com1Port = Nothing
        End Try
    End Sub
End Class

The port "COM1" does not exist.