I am trying to read the following data from 4 serial ports in VB.Net 2012

00056
00056
00056
00056
00056

Its 5 lines of data. The starting digit is a space and there are five digits after the space. I have tried so many different code but none has worked. I have searched only and had no success. All the samples I have seen talks to only one serial port. My newest code is as follows which I got from a Microsoft website. If I call this function 4 times will it work?

Code:
Public Function ReceiveSerialDataPort8() As String
        ' Receive strings from a serial port. 
        Dim returnStr As String = ""

        Dim com1 As IO.Ports.SerialPort = Nothing
        Try
            com1 = My.Computer.Ports.OpenSerialPort("COM8", 9600, Parity.None, 8, StopBits.One)
            com1.ReadTimeout = 10000
            Do
                Dim Incoming As String = com1.ReadLine()
                If Incoming Is Nothing Then
                    Exit Do
                Else
                    returnStr &= Incoming & vbCrLf
                End If
            Loop
        Catch ex As TimeoutException
            returnStr = "Error: Serial Port read timed out."
        Finally
            If com1 IsNot Nothing Then com1.Close()
        End Try

        Return returnStr
    End Function
Thanks,

Shaminda