Need some help please on creating Service for PABX Data Dumper Using VB 2005

[Lemune]

Hello everyone. I'm creating windows service application to capture
data from my PABX, and send the data to sql server. My question is how
could my application know when that PABX is sending data and not? I get
really confused here. Please check my code and give me some idea or
clue or help please :). Thanks in advance. My code is like this:

Dim DBConnection As SqlConnection
Dim WithEvents SPConnection As SerialPort = New
System.IO.Ports.SerialPort
Dim RawData As String

Private Sub ConnectingDB()

Dim connectionString As String = _
"Integrated Security=SSPI;Persist Security Info=False; " + _
"Initial Catalog=PABX;Data Source=USER/SQL2000"
DBConnection = New SqlConnection(connectionString)

DBConnection.Open()

End Sub
Private Sub SPConnection_DataReceived(ByVal sender As Object, _
ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) _
Handles SPConnection.DataReceived
RawData = SPConnection.ReadExisting()
SavetoDB()
End Sub

Private Sub SavetoDB()
Dim sqlTran As SqlTransaction = DBKoneksi.BeginTransaction()
Dim command As SqlCommand = DBKoneksi.CreateCommand()
command.Transaction = sqlTran

Try
command.CommandText = _
"INSERT INTO SampleTable VALUES(RawData)"
command.ExecuteNonQuery()
sqlTran.Commit()
Console.WriteLine("Both records were written to database.")
Catch ex As Exception
Console.WriteLine(ex.Message)
Console.WriteLine("Neither record was written to
database.")
sqlTran.Rollback()
End Try

End Sub

Protected Overrides Sub OnStart(ByVal args() As String)
With SPConnection
.PortName = "COM1"
.BaudRate = 57600
.Parity = Parity.None
.DataBits = 8
.StopBits = StopBits.One
End With
SPConnection.Open()
ConnectingDB()
End Sub

Protected Overrides Sub OnStop()
SPConnection.Close()
DBConnection.Close()
End Sub