From owner-freebsd-questions@FreeBSD.ORG Sun Apr 11 23:22:35 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F0A94106566C for ; Sun, 11 Apr 2010 23:22:35 +0000 (UTC) (envelope-from lin_g@o2.pl) Received: from mailout1.go2.pl (mailout1.go2.pl [193.17.41.11]) by mx1.freebsd.org (Postfix) with ESMTP id AAC1A8FC08 for ; Sun, 11 Apr 2010 23:22:35 +0000 (UTC) Received: from mailout1.go2.pl (unknown [10.0.0.103]) by mailout1.go2.pl (Postfix) with ESMTP id 73BD65D5149 for ; Mon, 12 Apr 2010 01:22:34 +0200 (CEST) Received: from unknown (unknown [10.0.0.142]) by mailout1.go2.pl (Postfix) with SMTP for ; Mon, 12 Apr 2010 01:22:34 +0200 (CEST) Received: from riviera.nat.student.pw.edu.pl [194.29.137.1] by poczta.o2.pl with ESMTP id rrCGbl; Mon, 12 Apr 2010 01:22:34 +0200 Message-ID: <4BC259BA.8020201@o2.pl> Date: Mon, 12 Apr 2010 01:22:34 +0200 From: Grzegorz Daniluk User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <4BC0800D.9030407@o2.pl> In-Reply-To: <4BC0800D.9030407@o2.pl> Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit X-O2-Trust: 2, 66 X-O2-SPF: neutral Subject: Re: reliable rs-232 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 Apr 2010 23:22:36 -0000 Thank you very much for all your advices. The device I'm going to 'talk to' is cesium clock with rs-232 interface. So it is not possible to simply change the interface to differential one. Connection cable can be short and the transmission speed can be slow. The most important thing for me is to ensure the long term communication. Not to lose any data is very important when periodically monitoring cesium parameters. We are speaking here about months and years of continous operation. That is why I'm afraid of something 'strange' happens to my rs-232 interface and communication. Maybe I'm too afraid of strange magic, but still, is it possible that my rs-232 could change its transmission parameters as a result of e.g. nearby elecrical interference ? Or, in general, what bad thing could happen to me in such scenario. Thanks a lot, Greg