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Serial port sniffer in qnx

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Serial port sniffer in qnx

Postby garyritu » Tue Jan 26, 2010 5:33 pm

Hi All,
I want to monitor serial port data under QNX system. Is there any tool in QNX to sniff the devc-ser8250 driver?
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Postby Tim » Tue Jan 26, 2010 6:26 pm


Not that I am aware of.

But you could get the source to devc-ser8250 and add some simple code to dump out the raw data sent/received to a file (on a RAM drive if you need real speed).

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Postby Buder » Wed Jan 27, 2010 6:44 am

Hi Gary

I have been working with serial ports and stepper motors and other custom serial protocols where I had to literaly sniff them (hack) to document a communication and then recreate this flow to control devices.

My approch to this was to set up a QNX computer and hook it up between the send/rec devices, and on that QNX sniffer (I think I used a laptop) use a simple read and write application that takes what it finds on the receiving port and relays it to the sending port and vice versa, even thou I had realtime to consider it worked perfectly, on the sniffer app that I wrote I could then detect the protocol and alter it so that I could see packages of messages being send back and forth. and ofcourse logg it to a file.

This was a truly powerful way of monitoring the "real" traffic as it happened for me. even thou it takes an extra computer (slow old one) it is a good tool to have at other cases when you are not using QNX on both sides, that way I could hook it up between Windows-QNX comunication as well as to stepper motor controllers-QNX or controller-Windows devices.

It was even good to have when I was at customers tracking bugs and problems in all kinds of serial systems. :)

If you are interested , please let me know and I will have a look where I have that code. :)


P.S. I have used the same app for RS232 and RS422/485 and it can probably be used for other interfaces as well.
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Postby lovelyp » Sat Jan 30, 2010 9:20 am


I have also done sniffer programs in QNX. Its simple. Just plug in a sniffer serial cable to a 3rd machine with QNX. Execute the sniffer app ritten by u which is just a simple serial read write program. It will definitely work. Always remember the sniffer application u wrote should be set in the same baud and data rate in which ur serial communication works
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Postby mario » Sun Jan 31, 2010 10:08 pm

isn`t that what qtalk does?
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Postby xtang » Mon Feb 01, 2010 3:15 am

no one mentioned "devc-ditto" ? :)
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Postby Buder » Mon Feb 01, 2010 9:50 am

True, qtalk seems possible to use, for some reason I found it hard to adapt to my liking and I wanted to "partition" the result without having all that "modem" oriented behaviour, since I did not do modems at the time, but still, try qtalk first . . :)

I did not have control of the sender/receiver at all so I had to sniff the physical signals.

sometimes simpler is better . .

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