CString strPort;
    BOOL fSuccess;
    COMMTIMEOUTS timeout;
    DCB dcb;

    strPort.Format("COM%d", nPortNo) ;

    //Create the handle for read the COM port
    m_hFile =  CreateFile( strPort,
                    GENERIC_READ | GENERIC_WRITE,
                    (DWORD)NULL,   // exclusive access
                    NULL,          // no security
                    OPEN_EXISTING,
                    FILE_ATTRIBUTE_NORMAL,
                    NULL           // hTemplate
                    );

    //Check weather the handle is valid or not
    if (INVALID_HANDLE_VALUE == m_hFile)
    {
        AfxMessageBox("Error: Could not open the RS232 port!", MB_OK|MB_ICONEXCLAMATION);
        return FALSE;
    }


    // set up the comms parameters now that we have a handle
    SetupComm(m_hFile,(DWORD)2048, (DWORD)2048);


    // Set up the DCB with our settings
    // Get it first so we fill all members
    fSuccess = GetCommState(m_hFile,&dcb);

    if (!fSuccess)
    {
        // Handle the error.
        AfxMessageBox ("Error: Failed to Get the System Communication Settings.", MB_OK|MB_ICONEXCLAMATION );
                return FALSE;
    }

    dcb.BaudRate = CBR_9600;
    dcb.ByteSize = 8;            // data size
    dcb.Parity = NOPARITY;        // No Parity Bit
    dcb.StopBits = ONESTOPBIT;

    // assign it
    fSuccess = SetCommState(m_hFile, &dcb);

    //Now check the configuration of the communication device is valid or
    //not after assign the comms parameters
    if ( fSuccess == 0 )
    {
        AfxMessageBox("Error: In Control Setting for a Serial Communications Device.", MB_OK|MB_ICONEXCLAMATION);
        return FALSE;
    }

    // Set up the timeouts to use, they are quite short, since we will loop anyway.
    // Do not make them zero, else we will have a CPU load problem. Too large a value,
    // and we have to wait for comms to time out when shutting down

    // fill timeout structure
    GetCommTimeouts(m_hFile, &timeout);
    timeout.ReadIntervalTimeout = 100;           // 500ms between incomming chars.
    timeout.ReadTotalTimeoutConstant = 500;
    timeout.ReadTotalTimeoutMultiplier = 0;
    timeout.WriteTotalTimeoutConstant = 2000;
    timeout.WriteTotalTimeoutMultiplier = 60;    // 60ms per char sent

    SetCommTimeouts(m_hFile, &timeout);

    return TRUE;

    unsigned char set_Data[15];

    // Prepare the Dummy Data for read and write the COM Port.
    for(int c=0; c<10; c++)
            set_Data[c] = 65 + c;

    // Write the Data to COM Port
    WriteToCOMPort(set_Data);

    unsigned char get_Data[15];

    ReadFromCOMPort(get_Data);

    m_txtRead.SetWindowText( (LPCTSTR)get_Data );
    CFormView::OnTimer(nIDEvent);

BOOL CReadCOMView::ReadFromCOMPort(unsigned char* c_Data)
{
    BOOL error;

    DWORD numberOfBytesRead = 0;
    error = ReadFile(m_hFile,
                c_Data,
                10,                 // Number Of Bytes To                 Read,
                &numberOfBytesRead,
                NULL);

    if(numberOfBytesRead == 0)
        return FALSE;

    c_Data[numberOfBytesRead] = '\0' ;
    SetDlgItemText(LBL_VIS_SLABEL, (LPCTSTR)c_Data);

    return TRUE;
}

BOOL CReadCOMView::WriteToCOMPort(unsigned char* c_Data)
{
    BOOL fSuccess;
    DWORD numberOfBytesWritten=0;

    // send the bytes out on the wire
    if (INVALID_HANDLE_VALUE == m_hFile)
    {
        MessageBox("Error: Cannot send. Port closed!\n");   // busy shutting down the app
        return FALSE;
    }

    fSuccess = WriteFile(m_hFile,
                c_Data,
                10,                 //  Number Of Bytes To                     Write,
                &numberOfBytesWritten,
                NULL);
    return TRUE;

    if(!fSuccess)
    {
        AfxMessageBox("Error: Could not Write the data to RS232 port!", MB_OK|MB_ICONEXCLAMATION);
        return FALSE;
    }
    return TRUE;
}