Article View: comp.dcom.lans.misc
Article #335Re: Multi-drop Serial Protocol Wanted (RS-232)
From: Michael Burke
Date: Thu, 28 Jan 1993 14:28
Date: Thu, 28 Jan 1993 14:28
30 lines
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1779 bytes
In article <1993Jan24.181433.26225@rosevax.rosemount.com> bill@texan.rosemount.com (William Hawkins) writes: >>jdc@isis.cs.wayne.edu (Jon Cardwell) writes: >>+--------------- >>| We're looking for sources or references for a "multi-drop serial protocol" >>| i.e. one that allows multiple devices to be attached to the same serial line. > >RS-232 is not a multi-drop protocol *electrically* because it holds >the line at the mark (or space) state. Hogwash... RS232 has been used for years with BSC 3270 multi-drop circuits. Generally, the trick is to use the fastest modem turn around time possible to get best results. The "poll-ack" protocols are above this physical standard. Remember, multi-drop does not mean a "bus architecture" in the strictest sense. One orders a multi-drop circuit from the Telco. I have not been involved with BSC 3270 circuits for many years (about 15) so I have no idea how one would go about building an in-house multi-drop circuit.... -- --- Michael Burke Sea Change Corporation 6695 Millcreek Drive, Unit 8 Mississauga, Ontario, Canada L5N 5R8 Tel: 416-542-9484 Fax: 416-542-9479 UUCP: ...!uunet!uunet.ca!seachg!burke
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arc1-ca.pugleaf.net!sparky!uunet!ukma!bogus.sura.net!howland.reston.ans.net!zaphod.mps.ohio-state.edu!uunet.ca!seachg!burkeReferences:
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Newsgroups: comp.dcom.lans.misc,comp.protocols.misc,comp.sources.wanted,comp.sys.misc Path: arc1-ca.pugleaf.net!sparky!uunet!ukma!bogus.sura.net!howland.reston.ans.net!zaphod.mps.ohio-state.edu!uunet.ca!seachg!burke From: burke@seachg.uucp (Michael Burke) Subject: Re: Multi-drop Serial Protocol Wanted (RS-232) Message-ID: <1993Jan28.142838.26423@seachg.uucp> Reply-To: burke@seachg.UUCP (Michael Burke) Organization: Sea Change Corporation, Mississauga, Ontario, Canada References: <v7kns3g@sgi.sgi.com> <1993Jan24.181433.26225@rosevax.rosemount.com> Date: Thu, 28 Jan 93 14:28:38 GMT Lines: 30