
Visit our shop for nerds in control lifestyle products.
- PC reliability?
- Windows, real time
- PID loops
- PCs vs. PLCs
- Replacing people
- MS 'monopoly'?
- Software quality
- Where do we go from here?
- Why pay?
www.control.com/rss
Sealevel Systems (http://www.sealevel.com) includes code samples on the software CD that ships with all serial products. 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.
----- Begin Code Sample -----
#include "stdafx.h"
#include
#include
#include
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;
}
If it is possible through the MSComm control then how?
Please guide me coz i am doing the same thing.
Kashif
affirmativeus@yahoo.com
- ODVA, DeviceNet: New CIP specs; ControlNet added; 2009 meeting
- Embedded, wireless devices, dynamic IP routing
- Listen in: Wireless developments for Air Force may influence industrial applications
- Easier implementation: Kits for cable testing, wireless products
- Inside look: How MTL Instruments fits with Cooper Industries
- Ethernet hardware: Switches and more
- Frost & Sullivan awards honors many automation, controls companies
- ABB update: User conference, exhibition, flow, SCADA, wireless
Users of this site are benefiting from open source technologies, including PHP, PostgreSQL and Apache. Be happy.
Patronize our advertisers!


