Using C++ for USB interfacing

[meepokman]

Five days after asking the question you write that you are using MFC! Good way to get help.
If you are using MFC, forget about C++/CLI and use plain Windows serial port API. You can use also some native serial port wrappers, available at CodeGuru and CodeProject. Serial port access is not a reason to use C++/CLI.
I wonder why the board vendor doesn't provide C++ code example. Using VB for serial port access is strange decision. Well, you are lucky that this is not JavaScript.

Hi Alex, thanks for the advice, sorry I did not mention the MFC earlier, still a bit of a noob at that.

Anyway, I tried this: http://www.codeproject.com/KB/system...ort.aspx#Usage and have followed the class calling in the demo program

class CSerialPortApp : public CWinApp
{
public:
  virtual BOOL InitInstance();
};
BOOL CSerialPortApp::InitInstance()
{
  BYTE* pBuf = new BYTE[10000];

  try
  {
    COMMCONFIG config;
    CSerialPort::GetDefaultConfig(1, config);

    CSerialPort port;
    port.Open(4, 1200, CSerialPort::NoParity, 8, CSerialPort::OneStopBit, CSerialPort::XonXoffFlowControl);

    HANDLE hPort = port.Detach();
    port.Attach(hPort);

    DWORD dwModemStatus;
    port.GetModemStatus(dwModemStatus);

    DCB dcb;
    port.GetState(dcb);

    dcb.BaudRate = 9600;
    port.SetState(dcb);    

    DWORD dwErrors;                      
    port.ClearError(dwErrors);

    port.SetBreak();
    port.ClearBreak();

    COMSTAT stat;
    port.GetStatus(stat);

    COMMTIMEOUTS timeouts;
    port.GetTimeouts(timeouts);

    port.Setup(10000, 10000);

    port.GetConfig(config);

    config.dcb.BaudRate = 9600;
    port.SetConfig(config);

    port.Set0WriteTimeout();
    port.Set0ReadTimeout();

    char sBuf[] = "This should appear on the serial port";
    port.Write(sBuf, strlen(sBuf));

    DWORD dwMask;
    port.GetMask(dwMask);

    port.SetMask(EV_TXEMPTY); 

    //port.WaitEvent(dwMask);

    port.TerminateOutstandingWrites();

    port.TransmitChar('p');

    port.Set0Timeout();

    char sRxBuf[10];
    DWORD dwRead = port.Read(sRxBuf, 10);

    port.TerminateOutstandingReads();

    port.ClearDTR();

    port.ClearRTS();

    port.SetDTR();

    port.SetRTS();

    port.SetXOFF();

    port.SetXON();

    COMMPROP properties;
    port.GetProperties(properties);

    port.ClearWriteBuffer();

    port.ClearReadBuffer();

    port.Flush();

    port.Close();
  }
   catch (CSerialException* pEx)
  {
    TRACE(_T("Handle Exception, Message:%s\n"), pEx->GetErrorMessage());
    pEx->Delete();
  }

  delete [] pBuf;
};

After doing this, I put the following code into the button

void CzebraDlg::OnBnClickedButton5()
{
	char mychar;
	CSerialPortApp theApp;
	 try {
    CSerialPort port;
    port.Open(4, 9600, CSerialPort::NoParity, 8, 
      CSerialPort::OneStopBit, 
      CSerialPort::XonXoffFlowControl);

    char sBuf[] = "@00 ON 0"; //THIS WILL BE SENT TO TURN ON RELAYS (TAKEN FROM BOARD MANUAL) 
    port.Write(sBuf, strlen(sBuf));
	Sleep(1000);			//RELAYS WITH REMAIN ON FOR 1 SECOND
	char sBuf2[] = "@00 OF 1";
	port.Write(sBuf2, strlen(sBuf));
    
}
catch (CSerialException* pEx)
{
   	 CerrorDlg  cid;  //*** Create an instance of our dialog
      cid.DoModal(); //Display Dialog box
}
	
}

The code compiles fine but when I click the button, nothing happens. It is meant to connect to COM4. Did I make a mistake somewhere? Thanks a lot in advance!!