serial port communication problem

Hi guys, i have a problem with the serial port communication. I am trying to read from the serial port, but it appears that only 14 bytes can be read at once. This is probably the size of the serial port receive buffer.
I have a serial extension card in my pc which adds 2 serial ports. With a null modem cable i can send data from one serial port to the other.

Code:

---

m_SerialPort.SetCommMask(EV_RXCHAR);

        if(m_SerialPort.WaitCommEvent(&dwEventMask, NULL))
        {
                unsigned char szBuf;
                DWORD dwIncomingReadSize;
                DWORD dwSize = 0;
                int iByteCount = 0;

                do
                {
                        if(m_SerialPort.ReadData(&szBuf, 1, &dwIncomingReadSize) != 0)
                        {
                                if(dwIncomingReadSize > 0)
                                {
                                        dwSize += dwIncomingReadSize;
                                        m_pReceiveBuf[iByteCount] = szBuf;
                                        iByteCount++;
                                }
                        }
                        else
                        {
                                // Handle error condition
                        }
                }while( (dwIncomingReadSize > 0) && (iByteCount < RECEIVE_BUF_SIZE) );

                *dwReceivedBytes = iByteCount;
        }

---

If i send 20 bytes i want to read 20 bytes at the other side. Does anybody have a solution for this problem?

It is completely unclear what m_SerialPort is and where and how you are using your code snippet.

You may want take a look at "Serial Communications in Win32" article and MTTTY sample in MSDN and J.Newcomer's essay Serial Port I/O

Thanks for the link Victor, i am studying it. I am running into a little problem here. How is a shutdown event created? It is passed as one of the parameters to the thread and i cannot figure out where it is coming from.

What serial port r u using RS232 or RS422? or the one which is present in all systems (COM)

Hi,

have you checked with another side , i.e How many bytes sent actually ?


-Anant

Thanks for the link Victor, i am studying it. I am running into a little problem here. How is a shutdown event created? It is passed as one of the parameters to the thread and i cannot figure out where it is coming from.