Date: Fri, 16 Feb 1996 18:26:02 +1030 (CST) From: Michael Smith <msmith@atrad.adelaide.edu.au> To: jkh@time.cdrom.com (Jordan K. Hubbard) Cc: msmith@atrad.adelaide.edu.au, hackers@FreeBSD.ORG Subject: Re: Multidrop serial (422/485) driver Message-ID: <199602160756.SAA27443@genesis.atrad.adelaide.edu.au> In-Reply-To: <361.824453314@time.cdrom.com> from "Jordan K. Hubbard" at Feb 15, 96 10:48:34 pm
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Jordan K. Hubbard stands accused of saying: > > > The 'mdsio' driver provides support for multidrop serial busses, either > > using a standard RS-422/485 interface card, or a standard RS-232 serial > > port with DTR- or RTS-controlled transmit/receive. > > Uh. Interesting. I wasn't aware that anyone was still playing with > serial networks since they dismantled BERKNET. :-) > > Are you guys actually using this stuff in such an application? It's called "industrial control". RS-485 is very heavily used in machine interfaces; properly wired it's nearly immune to interference, you can run it hundreds of metres over telephone cable, and it takes a $0.75 part to interface it to almost any UART or microcontroller. The 2000 olympics stadium at Homebush in Sydney is riddled with the stuff (cue Michael Butler 8), we use it for communications between our data acquisition systems and the associated radar transmitters; with an optically-isolated interface it doesn't suffer for being run in the same cable trays as the main antenna feeds (100KW+ @54MHz). > Jordan -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "I seek PEZ!" - The Tick [[
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