Hi everybody

I do want to send and receive ASCII-code over a RS232 interface. The communication speed should be as fast as possible. (Real-time application)

Is there somebody who allready has solved this problem? Or somebody who knows how to solve it?

Please write me a mail!
[email protected]
Thanks!

Kind regards
Etienne

 

Etienne,

Try http://www.codeproject.com

Search for the word "serial". They have several example projects one of which may work for you.

Best of Luck,

Alan

 

Take a look at the source for any Linux serial application. Nearly anything will send and recieve ascii with a serial port as fast as possible, the maximum baud rate is a trivial load for most processors these days. The Linux source is usually well done and is freely available, even in China.

Regards

cww

 

Etienne,

you can try the link below and review the documentation from dghcorp.com. It might be a start towards answering your question.

http://www.dghcorp.com/setupdll.exe

Regards,
DGH Tech Support

 

How's a Megabaud for fast?

http://news.thomasnet.com/fullstory/463117/772

 

<p>Sealevel Systems (http://www.sealevel.com) includes code samples on the software CD that ships with all serial products. Sealevel serial products, depending on models, can support up to 921K bps, or faster for RS-422/485.

<p>This C++ code sample shows you how to open a COM port, and send & receive data. In this example, data is sent and read at 460K bps, but standard windows ports are limited to 115K bps. If you are using a Real Time OS, you can also use overlapped I/O and double buffers, but that example is too long to demonstrate here.
<pre>
----- Begin Code Sample -----

#include "stdafx.h"
#include <stdio.h>
#include <conio.h>
#include <windows.h>
int main(int argc, char* argv[])
{
char INBUFFER[500];
char OUTBUFFER[20];
DWORD bytes_read = 0; // Number of bytes read from port
DWORD bytes_written = 0; // Number of bytes written to the port
HANDLE comport = NULL; // Handle COM port
int bStatus;
DCB comSettings; // Contains various port settings
COMMTIMEOUTS CommTimeouts;
strcpy(&OUTBUFFER[0], "The quick brown fox jumped over the lazy dog. \n\r\0");
// Open COM port
if ((comport =
CreateFile("\\\\.\\COM5", // open com5:
GENERIC_READ | GENERIC_WRITE, // for reading and writing
0, // exclusive access
NULL, // no security attributes
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL)) == INVALID_HANDLE_VALUE)
{
// error processing code goes here
}
// Set timeouts in milliseconds
CommTimeouts.ReadIntervalTimeout = 0;
CommTimeouts.ReadTotalTimeoutMultiplier = 0;
CommTimeouts.ReadTotalTimeoutConstant = 100;
CommTimeouts.WriteTotalTimeoutMultiplier = 0;
CommTimeouts.WriteTotalTimeoutConstant = 100;
bStatus = SetCommTimeouts(comport,&CommTimeouts);
if (bStatus != 0)
{
// error processing code goes here
}
// Set Port parameters.
// Make a call to GetCommState() first in order to fill
// the comSettings structure with all the necessary values.
// Then change the ones you want and call SetCommState().
GetCommState(comport, &comSettings);
comSettings.BaudRate = 460800;
comSettings.StopBits = ONESTOPBIT;
comSettings.ByteSize = 8;
comSettings.Parity = NOPARITY;
comSettings.fParity = FALSE;
bStatus = SetCommState(comport, &comSettings);
if (bStatus != 0)
{
// error processing code goes here
}
while(!kbhit())
{
bStatus = WriteFile(comport, // Handle
&OUTBUFFER, // Outgoing data
48, // Number of bytes to write
&bytes_written, // Number of bytes written
NULL);
if (bStatus != 0)
{
// error processing code here
}
bStatus = ReadFile(comport, // Handle
&INBUFFER, // Incoming data
500, // Number of bytes to read
&bytes_read, // Number of bytes read
NULL);
if (bStatus != 0)
{
// error processing code goes here
}
// code to do something with the data goes here
}
CloseHandle(comport);
return 0;
}
</pre>

 

if (bStatus != 0) { /* error processing code goes here */ }

... is not correct. The return values for SetCommTimeOuts() are as follows:

- If the function succeeds, the return value is nonzero.
- If the function fails, the return value is zero.


if (bStatus == 0) { /* error processing code goes here */ }

... should work

 

Ok, which DCB parameters need to be set to indicate "Flow Control = None"?? I it isn't as simple as DCB.FlowControl = Hardware or Xon/Xoff or None.