From owner-freebsd-hackers Sun Sep 7 22:15:24 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id WAA06779 for hackers-outgoing; Sun, 7 Sep 1997 22:15:24 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id WAA06761 for ; Sun, 7 Sep 1997 22:15:18 -0700 (PDT) Received: from word.smith.net.au (lot.atrad.adelaide.edu.au [203.20.121.21]) by genesis.atrad.adelaide.edu.au (8.8.5/8.7.3) with ESMTP id OAA24180 for ; Mon, 8 Sep 1997 14:45:15 +0930 (CST) Received: from word.smith.net.au ([127.0.0.1]) by word.smith.net.au (8.8.7/8.8.5) with ESMTP id LAA00840; Mon, 8 Sep 1997 11:41:23 +1000 (EST) Message-Id: <199709080141.LAA00840@word.smith.net.au> X-Mailer: exmh version 2.0zeta 7/24/97 To: "Jamil J. Weatherbee" cc: Joerg Wunsch , hackers@FreeBSD.ORG, jamil@acromail.ml.org Subject: Re: Speaking of device drivers. In-reply-to: Your message of "Sun, 07 Sep 1997 16:30:19 MST." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 08 Sep 1997 11:41:12 +1000 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk (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