From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Edwards Subject: Re: [PATCH] Documentation about RS485 serial communications Date: Tue, 16 Nov 2010 19:29:12 +0000 (UTC) Message-ID: References: <20100408111310.524f7354@lxorguk.ukuu.org.uk> <4CBD8EE4.5040808@evidence.eu.com> <201010191727.53314.alexander.stein@systec-electronic.com> <4CC418A9.6090602@evidence.eu.com> <4CDA630F.4060903@atmel.com> <20101110172842.GC12371@suse.de> <4CDBC3EC.6020707@evidence.eu.com> <20101116143016.GB6527@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from lo.gmane.org ([80.91.229.12]:58098 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753696Ab0KPT31 (ORCPT ); Tue, 16 Nov 2010 14:29:27 -0500 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1PIRDY-0008P6-Sl for linux-serial@vger.kernel.org; Tue, 16 Nov 2010 20:29:24 +0100 Received: from dsl.comtrol.com ([64.122.56.22]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 16 Nov 2010 20:29:24 +0100 Received: from grant.b.edwards by dsl.comtrol.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 16 Nov 2010 20:29:24 +0100 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org On 2010-11-16, Matt Schulte wrote: >>> In my opinion this type of card is not that common. ?Generally >>> speaking the achievable baud rates for this type of multi-protocol >>> card are very limited because of limitations of the transceiver >>> chips. >> >> I'm curious which selectable interface cards you're talking about >> that are slow? ?The ones I'm familiar with generally support baud >> rates up to either 460K bps or 921K bps >> >>> It seems that most of the time people would rather have a faster >>> serial port than one that does several different voltages. >> >> Where did you find a selectable interface serial card that couldn't >> support high baud rates? > > In my world 460kbps for an RS422 card is slow. RS422 cards generally > push multi megabit/s rates. Ah, I see. That's a completely different market than the markets served by the multi-interface cards that typically max out at 921K. I've support multi-interface cards for years and years, and I find it very rare that anybody uses anything much faster than 19.2K. -- Grant Edwards grant.b.edwards Yow! TAILFINS!! ... click at ... gmail.com