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08.15.2008 at 03:55AM PDT, ID: 23650906
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8.8

Working with Overlapped I/O over a serial connection

Asked by NK0d3R in Microsoft Visual C++, Windows MFC Programming, Microsoft Development

Tags: ,

I need help with the code attached. I need to get all the data a device connected to my serial port sends in a given amount of time. The problem is the device doesn`t send it all in one bulk, it first sends 12 bytes, then it waits for ~10-15 secs, then sends some larger amounts of data. My code just extracts the first 12 bytes sent, and even though the device sends the other data too, I`m just left with my 12 bytes after waiting for 60 seconds. Some hints would be extremely appreciated, as i`m quite stuck here. Thank youStart Free Trial 
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DCB connProp;
	
	if	(!GetCommState(m_connection,&connProp))
	{
		return false;
	}
 
	connProp.BaudRate = CBR_115200;
	connProp.Parity = 0;
	connProp.StopBits = ONESTOPBIT;
	connProp.ByteSize = 8;
 
	connProp.fTXContinueOnXoff = FALSE;
	connProp.fOutxCtsFlow = FALSE;
    connProp.fOutxDsrFlow = FALSE;
    connProp.fOutX = FALSE;
    connProp.fInX = FALSE;
	connProp.fDsrSensitivity = FALSE;
	connProp.fNull = FALSE;
 
	if (!SetCommState(m_connection,&connProp))
	{
		return false;
	}
 
	COMMTIMEOUTS cto;
 
	cto.ReadIntervalTimeout = 100;
	cto.ReadTotalTimeoutConstant = 100;
	cto.ReadTotalTimeoutMultiplier = 100;
	cto.WriteTotalTimeoutConstant = 100;
	cto.WriteTotalTimeoutMultiplier = 100;
 
	if (!SetCommTimeouts(m_connection, &cto))
	{
		return false;
	}
 
////////////////////////////////////////////
 
 
long startTimer = GetTickCount ();
 
	do
	{
		
		if (readSafe)
		{
			if (!ReadFile(m_connection, m_rawData + crtPos, 1, &bytesRead, &oLap)) 
			{
				if (GetLastError()!= ERROR_IO_PENDING)
				{
					CloseHandle(oLap.hEvent);
					return false;
				}
				else
				{
					readSafe = false;
				}
			}
			else
			{
				crtPos += bytesRead;
				readSafe = true;
			}
		}
		
		if (!readSafe)
		{
	
				DWORD result;
				result = WaitForSingleObject(oLap.hEvent, 100);
				switch (result)
				{
				case WAIT_OBJECT_0:
 
					if (!GetOverlappedResult(m_connection, &oLap, &bytesRead, TRUE))
					{
						CloseHandle(oLap.hEvent);
						return false;
					}
					else
					{
						readSafe = true;
						crtPos += bytesRead;
					}
					break;
 
				case WAIT_TIMEOUT:
				
					break;                       
 
				default:	
					CloseHandle(oLap.hEvent);
					return false;
					break;
 
				}
 
			}
 
	
 
	}while (GetTickCount () - startTimer < MAX_WAIT_MILISEC);
 
Keywords: Working with Overlapped I/O over a s…
Title
1 SHOW HINT
2 Multi threaded non-overlapped I/O
3 How do I validate overlapping date/tim…
4 |How to read input from serial port?
5 Hint...
6 CF hangs on bulk insert
 
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[+][-]08.19.2008 at 03:01AM PDT, ID: 22258366

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About this solution

Zones: Microsoft Visual C++, Windows MFC Programming, Microsoft Development
Tags: Microsoft, Visual C++
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Solution Provided By: DanRollins
Participating Experts: 1
Solution Grade: A
 
 
[+][-]09.17.2008 at 07:18PM PDT, ID: 22506414

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[+][-]09.21.2008 at 06:53PM PDT, ID: 22536901

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