serial port communication problem

[hmc]

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.

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?

[VictorN]

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

[hmc]

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.

[danandu]

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

[anantwakode]

Hi,

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


-Anant

[hmc]

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.