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POSerial Comm using WriteFile/ReadFile
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  1. POSerial Comm using WriteFile/ReadFile
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    copied!<pre><code>//#include "StdAfx.h" #include &lt;stdio.h&gt; #include &lt;windows.h&gt; #include &lt;winbase.h&gt; #include &lt;iostream&gt; #include &lt;tchar.h&gt; using namespace std; int main() { int com = 'COM2'; string data = "\n 010400 \n"; char output[32]; //unsigned int length = 0; DCB config = {0}; bool abContinue = true; DWORD dwBytesWritten; DWORD dwBytesRead; int isRead = false; HANDLE m_hCommPort = ::CreateFile(L"COM2", GENERIC_READ|GENERIC_WRITE,//access ( read and write) 0, //(share) 0:cannot share the COM port 0, //security (None) OPEN_EXISTING,// creation : open_existing 0, // we dont want overlapped operation 0// no templates file for COM port... ); config.DCBlength = sizeof(config); if((GetCommState(m_hCommPort, &amp;config) == 0)) { printf("Get configuration port has a problem."); return FALSE; } config.BaudRate = 9600; config.StopBits = ONESTOPBIT; config.Parity = PARITY_NONE; config.ByteSize = DATABITS_8; config.fDtrControl = 0; config.fRtsControl = 0; if (!SetCommState(m_hCommPort, &amp;config)) { printf( "Failed to Set Comm State Reason: %d\n",GetLastError()); //return E_FAIL; } printf("Current Settings\n Baud Rate %d\n Parity %d\n Byte Size %d\n Stop Bits %d", config.BaudRate, config.Parity, config.ByteSize, config.StopBits); int isWritten = WriteFile(m_hCommPort, &amp;data,(DWORD) sizeof(data), &amp;dwBytesWritten, NULL); //memset(output, 0, sizeof(output)); while (abContinue) { isRead = ReadFile(m_hCommPort, output, sizeof(output), &amp;dwBytesRead, NULL); if(!isRead) { abContinue = false; break; } } cin.get(); } </code></pre> <p>I am having trouble reading from the com port. If I step through the code, it goes into "isRead = ReadFile(m_hCommPort, output, sizeof(output), &amp;dwBytesRead, NULL);" and doesn't come back out.... This is my first try at this with no success.</p>
 

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