Re: tcpdump equivalent for the serial port

[Nicolae Mihalache <mache@abcpages.com>]

Mariano Moreyra wrote:

>Hi Nicolae,
>
Hi Mariano!

>I think that what you want to do is not posible just with a software.
>You have to build a special cable to do that (somebody tell me if I'm wrong,
>or if knows another option)
>In my job we have one of those cables because we needed to see what was
>going on between two applications that talk to each other via serial port.
>The bad thing is that you need a third computer that would be the sniffer.
>
The problem is that opening the cable and connecting it to a third port 
may introduce some variations in the signals going over the serial 
cable. This is something that I want to avoid as much as possible. The 
other end of the serial cable is not another computer but a device that 
is itself the subject of development and test so it can not be assumed 
as working nor it can be developed with a non-nominal serial cable 
connected to it. Even worse, my serial link is not RS232 but RS422 which 
has a higher speed and it's more difficult to have break-out capability 
without interferences.
This is why I'm looking for a software solution, i.e. something that 
communicates with the serial driver and gets all the messages that pass 
through it.

Nicolae