RS232 Sniffing


+ Reply to Thread
Results 1 to 14 of 14

Thread: RS232 Sniffing

  1. #1
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default RS232 Sniffing

    I'd like to monitor a PC program communicating with a serially connected device with a simple tool, so that I can see what PC is sending and what the device is replying to PC.

    I know I can do this with another RS232 and a couple of diodes and resistors but prefer to not use an extra serial port. A simple monitoring window is better.

    Anyone that knows such a tool please?

    Ioannis

  2. #2
    Join Date
    May 2013
    Location
    australia
    Posts
    2,368

    Default Re: RS232 Sniffing

    this worked for me to monitor ports
    https://sourceforge.net/projects/realterm/
    Warning I'm not a teacher

  3. #3
    Join Date
    Nov 2005
    Location
    Bombay, India
    Posts
    947

    Default Re: RS232 Sniffing

    You might want to consider this product. I have used a very early version of it and think it might be what you're looking for. https://www.hhdsoftware.com/serial-port-monitor

  4. #4
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default Re: RS232 Sniffing

    Thank you both.

    The second seems a bit more complicated but more loaded with features.

    Ioannis

  5. #5
    Join Date
    Nov 2005
    Location
    Bombay, India
    Posts
    947

    Default Re: RS232 Sniffing

    Hi Ioannis

    The serial port monitor software sits on top of your existing serial port driver on the same PC which communicates with the device. So, you can run your PC software with your device and intercept all the traffic passing to / from the device.

    Therefore, whatever traffic passes through the serial port on the PC, it can intercept and display.

    Regards

  6. #6
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default Re: RS232 Sniffing

    Yes, it is a great tool! Thanks,

    Ioannis

  7. #7

    Default Re: RS232 Sniffing

    one thing you could do if you don't need data in real time is LOG the traffic to file, then read it. Hyperterm can log text and so can realterm I think. Some terminal programs may be able to add time-stamp to dats logged'

  8. #8
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default Re: RS232 Sniffing

    Good idea. Especially if there is a way to disciminate the Tx from Rx data stream.

    Thanks,
    Ioannis

  9. #9

    Default Re: RS232 Sniffing

    this simple circuit worked with PIC serial TTL to USB for send/rcv to PC. Just used a second USB to serial converter and actually used a 1K ohm R, then can view both sending and receiving. Open another instance of hyper-term or other terminal program. You could add 3rd USB/serial device and open another terminal prog and see separate send rcv windows
    Name:  ht3.PNG
Views: 2132
Size:  10.8 KBName:  ht1.PNG
Views: 2068
Size:  269.5 KBName:  ht2.PNG
Views: 1758
Size:  171.6 KB

  10. #10
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default Re: RS232 Sniffing

    Thanks amgen.

    My preference is to use a software solution than to use an extra serial port.

    Ioannis

  11. #11
    Join Date
    Aug 2011
    Posts
    407

    Default Re: RS232 Sniffing

    Try com0com (and some of its associated programs like hub4com). It lets you create virtual ports from a single com port.

    https://com0com.sourceforge.net/

  12. #12
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default Re: RS232 Sniffing

    Nice project this com0com. Will use them in Com to TCP/IP.

    But for now I wanted to monitor a real device communicationg with the PC app.

    Thanks,

    Ioannis

  13. #13
    Join Date
    Aug 2011
    Posts
    407

    Default Re: RS232 Sniffing

    It should do that too.

    Hub4com let's you create multiple virtual ports, so you can pipe one real port out to multiple apps

  14. #14
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,766

    Default Re: RS232 Sniffing

    Thanks a lot for the suggestions and links.

    Ioannis

Similar Threads

  1. rs232
    By rondo2 in forum General
    Replies: 20
    Last Post: - 1st July 2009, 02:06
  2. RS232 to RS485
    By The Master in forum Off Topic
    Replies: 22
    Last Post: - 16th October 2008, 16:37
  3. RS232 into 2 PC ports
    By manxman in forum mel PIC BASIC Pro
    Replies: 2
    Last Post: - 30th August 2008, 14:33
  4. PC to PIC via RS232
    By Martin.... in forum mel PIC BASIC
    Replies: 3
    Last Post: - 15th September 2006, 11:44
  5. Baud sniffing
    By anj in forum mel PIC BASIC Pro
    Replies: 0
    Last Post: - 3rd January 2005, 22:56

Members who have read this thread : 12

You do not have permission to view the list of names.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts