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Com Port Createfile Error 2


Joerg Back to top Post karma: +0 / -0 neillybee Joined: 04 Apr 2006Posts: 29 Post karma: +5 / -2Location: Somerset, UK Posted: Sat Nov 08, 2008 10:38 am We appreciate your feedback. I'm pretty convinced that if I can figure out the syntax for referencing the COM port, it should work. I'm certain COM1 exists because it shows up in device manager and I can use another terminal application (TeraTerm) and it shows up there. Source

This is a *.c file and I am compiling it as such...) 06-13-2012 #4 Salem View Profile View Forum Posts and the hat of int overfl Join Date Aug 2001 Location dwCreationDisposition [in] An action to take on a file or device that exists or does not exist. See Obtaining and Setting File Information and GetFileInformationByHandle. You cannot request an access mode that conflicts with the sharing mode that is specified by the dwShareMode parameter in an open request that already has an open handle. http://stackoverflow.com/questions/14634954/createfile-returns-error-invalid-handle-value-for-com-port-and-getlasterror-r

Createfile C++

If there are existing open handles to a file, the call fails unless they were all opened with the FILE_SHARE_DELETE share mode. For more information, see Automatic Propagation of Inheritable ACEs. Run the exe with; infilecopy .\\Test.txt .\\Test2.txt What happens? Error: %x\n", GetLastError()); return 3; } while(ReadFile(hIn, buffer, BUF_SIZE, &nIn, NULL) && nIn > 0) { WriteFile(hOut, buffer, nIn, &nOut, NULL); if(nIn != nOut) { printf("Fatal write error: %x\n", GetLastError()); return

FILE_ATTRIBUTE_ENCRYPTED 16384 (0x4000) The file or directory is encrypted. Physical Disks and Volumes Direct access to the disk or to a volume is restricted. For more information, see the Caching Behavior section of this topic. Generic_read Hans Passant.

If you know of another site that might have answers let me know (or the correct forum). The TEXT macro only wants a quoted string. The last of these will probably use a 'virtual port'. Here's a the snippet that doesn't seem to work:HANDLE SerialPortHandle; SerialPortHandle = CreateFile (TEXT("COM1:"),GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL); More than a few of the code examples I've seen are passing the first argument of CreateFile as "COM1:" without the TEXT() macro

It ran just fine and opened the COM port with no issues. Msdn Writefile Access to the directory is denied if this is done. Mark 04-17-2013 #7 DougD720 View Profile View Forum Posts Registered User Join Date Mar 2011 Location USA Posts 17 Thanks guys I'd appreciate it. Browse other questions tagged c++ serial-port or ask your own question.

Createfile Example

The port string doesn't need to be in ASCII - _T forces the string to be in the current character width, which could be either char or wchar_t depending on compilation https://www.experts-exchange.com/questions/27217546/CreateFile-COM-port.html The opening process can duplicate the handle as many times as required, but after it is opened, the named pipe instance cannot be opened by another client. Createfile C++ Not sure why ? Createfile C# Wednesday, September 10, 2008 1:53 PM Reply | Quote 0 Sign in to vote OK, I've done some more testing.

When I get a chance, I'll add some more debug to the comm test code to see the differences in the raw data with CreateFileA vs CreateFileW. this contact form Thanks! Specify the GENERIC_READ access right instead. I've attempted using the same function call but passing argument 1 as TEXT("COM2:") and a number of other COM port numbers (all of them up to 8) and had no success. Createfile Com Port

This flag should not be used if read-behind (that is, reverse scans) will be used. If CREATE_ALWAYS and FILE_ATTRIBUTE_NORMAL are specified, CreateFile fails and sets the last error to ERROR_ACCESS_DENIED if the file exists and has the FILE_ATTRIBUTE_HIDDEN or FILE_ATTRIBUTE_SYSTEM attribute. Actually I have to say that "COM1" has always worked for me I assume you computer has a COM1? have a peek here Thanks!

For a file, this means that all data in the file is encrypted. File_share_read For communications resources, the dwCreationDisposition parameter must be OPEN_EXISTING, the dwShareMode parameter must be zero (exclusive access), and the hTemplateFile parameter must be NULL. Security flagMeaning SECURITY_ANONYMOUS Impersonates a client at the Anonymous impersonation level.

lpSecurityAttributes If you want the console to be inherited, the bInheritHandle member of the SECURITY_ATTRIBUTES structure must be TRUE.

How do I get the last lines of dust into the dustpan? SECURITY_CONTEXT_TRACKING The security tracking mode is dynamic. This flag has no effect if FILE_ATTRIBUTE_SYSTEM is also specified. Readfile Msdn If you choose to participate, the online survey will be presented to you when you leave the Msdn Web site.Would you like to participate?

OPEN_EXISTING 3 Opens a file or device, only if it exists. After clicking ok to get rid of the error message, I can't access my database. shooting for the quick easy fix. http://ogdomains.com/com-port/com-port-error-2.php To open a directory using CreateFile, specify the FILE_FLAG_BACKUP_SEMANTICS flag as part of dwFlagsAndAttributes.

char * port_name = "COM1"; hCom = CreateFile(port_name, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, However the FLychart program only wants to read from port one... FILE_ATTRIBUTE_READONLY 1 (0x1) The file is read only. If an application moves the file pointer for random access, optimum caching performance most likely will not occur.

SECURITY_IDENTIFICATION Impersonates a client at the Identification impersonation level. When opening a volume or floppy disk, the dwShareMode parameter must have the FILE_SHARE_WRITEflag. Cached information includes its short/long name pair and creation time. I'll just have to change that from now on when working from the code in the book I'm using.

When an application creates a file across a network, it is better to use GENERIC_READ | GENERIC_WRITE for dwDesiredAccess than to use GENERIC_WRITE alone. Should hamburger menu be on left or the right? If the file is not a reparse point, then this flag is ignored. For more information about devices, see the Remarks section.