Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!mcvax!enea!pvab!robert
From: robert@pvab.UUCP (Robert Claeson)
Newsgroups: comp.dcom.modems,news.sysadmin
Subject: Re: Hardware Protocol
Message-ID: <305@pvab.UUCP>
Date: Mon, 24-Aug-87 05:10:54 EDT
Article-I.D.: pvab.305
Posted: Mon Aug 24 05:10:54 1987
Date-Received: Tue, 25-Aug-87 04:32:16 EDT
References: <192@caeco.UUCP> <2849@phri.UUCP> <1103@laidbak.UUCP> <1172@geac.UUCP> <419@piaget.UUCP> <374@pcrat.UUCP>
Reply-To: robert@pvab.UUCP (Robert Claeson)
Organization: Statskonsult Programvaruhuset AB, Sweden
Lines: 24
Keywords: RS-232 CTS flow-control
Xref: mnetor comp.dcom.modems:863 news.sysadmin:339

In article <374@pcrat.UUCP> rick@pcrat.UUCP (rick) writes:

   .....
>However, what I think we were originally discussing is the defacto standard
>of using RTS/CTS in a *full duplex* environment to provide *two way* flow
>control.  In this scheme, CTS is still used by the DCE to flow control
>the DTE.   However, there is no relationship between RTS and CTS anymore.
>Instead, RTS is given a new meaning.  When the DTE wants to flow control
>the DCE, it deasserts RTS.  Think of RTS as "Receiver Ready" and it
>makes good sense.  I don't know how many vendors implement this in
>their products, but I know that AT&T does in some of its product line.
   .....

Aren't there pins named "Secondary DCD, CTS, RTS" and some others at pin
12, 13, and 19? Can't they be used to provide a "real" two-way flow control
without violating the RS232 standard?

I can't find any documentation on the RS422/RS423 standards. Doesn't one
of those standards provide full-duplex handshaking?

-- 
SNAIL:	Robert Claeson, PVAB, P.O. Box 4040, S-171 04 Solna, Sweden
UUCP:	{seismo,mcvax,munnari}!enea!pvab!robert
ARPA:	enea!pvab!robert@seismo.arpa