[ale] Monitoring the serial port

James P. Kinney III jkinney at localnetsolutions.com
Wed Sep 4 20:54:19 EDT 2002


John,

The ingenuity of this group never ceases to amaze me!  Spiffy idea. Of
the top of your head, do you know what the load limits _should_ be? 

On Wed, 2002-09-04 at 16:05, John Mills wrote:
> ALErs-
> 
> On Wed, 4 Sep 2002, Pete Hardie wrote:
> 
> > John C wrote:
> > > Does anyone know of a way to capture serial port output of a device onto a
> > > Linux system and log everyting it sees to a file?
>  
> > cat < /dev/ttyS2 > /log/logfile is a simplistic way
> 
> I've used 'minicom' for this - in fact I had a pair of them running to
> capture traffic both ways on the RS-232C line between a Win box and a
> radio, roughly thus:
>                                    'Breakout'
>                                     connector
>             TxD                     ........              RxD
>          >>>--------------------->>------+--->>--------------->>>
>   WinBox    RxD                     .    |.               TxD    Radio
>          <<<---------------------<<----+-|---<<---------------<<<
>                                     ...|.|.. 
>                                        V V
>                                        V V
>   LinBox          RxD                  | |
>    Minicom(1) <<<----------------------+ |
>                   RxD                    |
>    Minicom(2) <<<------------------------+
> 
> Salient points:
>   1) A special cable was built (actually a M-F in-line breakout connector)
>      which brought out the two signal lines and routed each of them to
>      the RxD of a separate serial port on the Linux box.
> 
>   2) This clearly violates the usual load spec on RS-232C drivers, but
>      with short cables it was no problem.
> 
>   3) The two Minicoms were each started with different "capture file"
>      ('-C <filename>' option)
> 
>   4) The TxD ports of those two LinBox serial ports were not connected,
>      so by turning on 'echo' at the Minicoms, I could enter notes into
>      the log files by simply typing into the respective Minicom window.
>      That also allowed me to establish their sequencing for later
>      comparison of 'inquiry/command' and 'reply'.
> 
> I had bought a Win utility for this, and never even used it - I preferred 
> the two-window annotation approach.
> 
>  - John Mills
> 
> 
> ---
> This message has been sent through the ALE general discussion list.
> See http://www.ale.org/mailing-lists.shtml for more info. Problems should be 
> sent to listmaster at ale dot org.
-- 
James P. Kinney III   \Changing the mobile computing world/
President and CEO      \          one Linux user         /
Local Net Solutions,LLC \           at a time.          /
770-493-8244             \.___________________________./

GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics)
<jkinney at localnetsolutions.com>
Fingerprint = 3C9E 6366 54FC A3FE BA4D 0659 6190 ADC3 829C 6CA7 



 This is a digitally signed message part




More information about the Ale mailing list