Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 08 Sep 1997 11:41:12 +1000
From:      Mike Smith <mike@smith.net.au>
To:        "Jamil J. Weatherbee" <jamil@counterintelligence.ml.org>
Cc:        Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de>, hackers@FreeBSD.ORG, jamil@acromail.ml.org
Subject:   Re: Speaking of device drivers. 
Message-ID:  <199709080141.LAA00840@word.smith.net.au>
In-Reply-To: Your message of "Sun, 07 Sep 1997 16:30:19 MST." <Pine.BSF.3.96.970907161318.676A-100000@counterintelligence.ml.org> 

next in thread | previous in thread | raw e-mail | index | archive | help

(Please, for your sake, try to learn something about the concept of the
"paragraph" and the "sentence".)

> I am currently working on a piece of software (actually an expansion of an
> earlier product), in house as a consultant for a small company. It
> involves the coordination of a horrendous number of sensors/actuators
> attached to a number of networked freebsd machines.

Can you qualify "horrendous"?  Unless there's something *really* 
horrendous about it, I think you're already off on the wrong foot.

> Like I've said this is a
> work in progress but I think that the concept could be generalized a bit
> more to include the equivalent of nfs for character devices -- my
> authentication right now is by serial keys and device description shared
> by client and server.

Sounds like a lot of overkill, IMHO.  This isn't the sort of thing you 
want in an industrial environment.

>From my POV I would be using one or more RS-485 links and either custom 
slaves at suitable points or off-the-shelf 485 slaves like the 
Advantech ADAM modules.  The only time this breaks down is when you 
have precise timing requirements between multiple slaves, and often the 
easiest way to go then is to have a separate transmit-only time-sync 
bus.

mike





Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199709080141.LAA00840>