How to write a C++ program to record the Serial Port I/O traffic?

[centurion11]

Hi All,

Anyone know know to write a C++ program that able to record all the data that send to and receive from device through Serial Port (COM1)?

[Banfa]

Which program is doing the sending an receiving? The program you are going to write?

If not then this is not an easy task and may be impossible because in general a serial port can only be owned by 1 application at a time so the application sending an receiving the data will be the one that owns the port and you will not be able to see what is happening.

[horace1]

Hi All,

Anyone know know to write a C++ program that able to record all the data that send to and receive from device through Serial Port (COM1)?

probably the simplest way is to to tap into the serial cable bewteen the devices and take a line into another serial port (on another PC?} which can listen to one side of the communications (or into two serial ports to listen to both side)

a cable something like
http://www.rs232pro.com/rs232/half_duplex.htm
or you could make one - all you need is three 9 pin D-type connectors and some cable

or you could use a RS232 break out box
http://www.lashen.com/products/tools/CZ_32-122.asp

[centurion11]

Thanks banfa & Horace1,
I get what u guys mean, so there is no way to trace the RS232 communication data? My condition is, my PC is connected to a printer, and i want to know what data are sent n received by my PC, any idea of creating C++ software to do this?

[centurion11]

probably the simplest way is to to tap into the serial cable bewteen the devices and take a line into another serial port (on another PC?} which can listen to one side of the communications (or into two serial ports to listen to both side)

a cable something like
http://www.rs232pro.com/rs232/half_duplex.htm
or you could make one - all you need is three 9 pin D-type connectors and some cable

or you could use a RS232 break out box
http://www.lashen.com/products/tools/CZ_32-122.asp

Hi Horace1,

I tried to compile the code you post in topic "reading data from barcode reader" http://www.thescripts.com/forum/thread569742.html

and i found this error:
1>.\a.cpp(26) : error C2664: 'CreateFileW' : cannot convert parameter 1 from 'char [5]' to 'LPCWSTR'

from:
hCom = CreateFile(ComPortName, GENERIC_READ | GENERIC_WRITE,
0, // exclusive access
NULL, // no security
OPEN_EXISTING,
0, // no overlapped I/O
NULL); // null template

do you know what it is? i'm using visual studio C++ on windows XP.

[centurion11]

Hi Banfa n horace1,

I'm going to use another PC to read the data transfered between a PC and a printer, i'm using COM1 & COM2:
COM1 will read the data sent by PC to printer
COM2 will read the data sent by printer to PC

Do you have a program doing this, or any idea of doing this?
I'm using VS C++ on windows XP, and I'm beginner in programming. Thanks for your help. Really appreciate it.

[horace1]

Hi Banfa n horace1,

I'm going to use another PC to read the data transfered between a PC and a printer, i'm using COM1 & COM2:
COM1 will read the data sent by PC to printer
COM2 will read the data sent by printer to PC

Do you have a program doing this, or any idea of doing this?
I'm using VS C++ on windows XP, and I'm beginner in programming. Thanks for your help. Really appreciate it.

I don't use Visual C so have no direct experience of using serial IO with it.

When I did a google search on "visual C++ serial IO" it turned up a list of useful looking links with example serial IO code which you should be able to adapt

[ajain]

hey i'v been working on serial com port for quiet some time. use the bioscom and _bios_serialcom, with them u can actually monitor the status of any of the COM ports...here is a c program to do tht...c if it proves to b of some help in ur c++ code.do change ur device adress...

#include<stdio.h>
#include<conio.h>
#include<bios.h>
#include<time.h>
#include<dos.h>
 
 
#define COM1 0x03F8
#define COM2 0x02F8
#define DATA_READY 0X60B0
#define SETTINGS (_COM_9600|_COM_NOPARITY|_COM_STOP1|_COM_CHR8)
 
    int start_addr();
    int end_addr();
    void group_addr();
    void display_time();
    void transmit_frame(int*,int*);
    void recieve_frame(int*);
 
 
    void main(void)
 
    {
         char send;
         int abyte,in;
         int a,b,c,r,addr,status;
         unsigned int ret_value;
         int count, arr[6];
         int bit_num,s_addr, e_addr;
         int parity, baud,port,mode;
         int com_port_no,stop_bit;
         char abyte_stopbit, abyte_baud, abyte_parity,abyte_databit;
         char arr_baud[]= {0x00, 0x20, 0x40, 0x60,0x80,0xA0,0xC0,0xE0};;
 
         clrscr();
 
          //COM PORT SELECT SETTINGS//
         printf("\nSelect COM Port\nCOM 1\nCOM 2\n");
         scanf("%d",&com_port_no);
         switch(com_port_no)
            {
             case 1:port = 0;
                break;
 
             case 2:port =1;
                break;
            }
 
 
                        //TRANSMISSION MODE//
                  clrscr();
                 addr = start_addr();
                 printf("\nESC to exit\n");
                // for(;;)
 
                    {
                transmit_frame(&addr,&port);
                    delay(5);
                    printf("\n");
                    recieve_frame(&port);
                    }
                  printf("\n");
 
 
 
 
        getch();
 
        }
 
     void transmit_frame(int*addr,int*port)
        {
 
         unsigned int in;
         int trans,i;
         char arr[] = {0x01};
 
 
 
         if(kbhit())
            {
               if(getch()=='\x1B')
                { exit(0);
                }
            }
         else
            {
                trans = arr[0];
                printf("%x ",trans);
                _bios_serialcom(_COM_SEND,*port, trans);
                delay(100);
            }
 
        }
 
 
 
    void recieve_frame(int*port)
        {int v;
        int trans;
 
        unsigned int status,out;
     {
       status = _bios_serialcom_COM_STATUS,*port,SETTINGS);
       printf("%x",status);
 
              out=_bios_serialcom(_COM_RECEIVE,*port,0);
              trans = out;
              printf("\n%x",trans);
 
 
 
         }
 
         }
 
    start_addr()
        {int s_addr1;
        printf("\nStart Address:");
        scanf("%x",&s_addr1);
        return(s_addr1);
        }