Guy Harris wrote:
...there are (at least) two issues I see:
1) getting Profibus signals from some USB device;
2) decoding the resulting information.
1) is a problem that is mainly a non-Ethereal problem.
If you can solve 1) in a fashion that lets you, for example, read
Profibus signal information into a file, *and* that the file can be
broken into packets - i.e., that Profibus is a packet-oriented protocol,
and that you'll be analyzing packets rather than, for example, signal
waveforms (Ethereal isn't a waveform analyzer) - then the only part of
1) that would involve Ethereal would be writing code to read the file,
and then you'd write a dissector for Profibus that processes the data
you'd read from the file.
Do you mean that I must write a program that will read on the USB port and
will write Profibus packets on a file that Ethereal will be able to analyse
with a Profibus dissector ?