Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!decwrl!decvax!tektronix!tekig5!jacc
From: jacc@tekig5.PEN.TEK.COM (Jac Colby)
Newsgroups: comp.dcom.modems
Subject: Standardization of RTS-CTS flow control (RS-232)
Keywords: CCITT V.24 X.20 RS-232 RTS CTS standard
Message-ID: <3730@tekig5.PEN.TEK.COM>
Date: 30 Jan 89 20:38:42 GMT
Organization: Tektronix, Inc.
Lines: 29

Hold-off, line eater!

I am looking for any standard that covers the use of RS-232 RTS-CTS
signals for bi-directional flow control in the way that "smart" modems
commonly use them.  EIA-232-D, of course, defines RTS quite differently
from the way it is now commonly used.  TSB-24 from EIA appears to
suitably define CTS, but I have yet to find any formal standardization
for the use of RTS.

I have been told that CCITT addressed this subject at their November
plenary meeting, but I have no details.  It may be covered in the new
"blue books" (V.24 or X.20?), or as a separate item.  If anyone has
knowledge of or access to the CCITT minutes/drafts/etc., would you
please let me know whether or not RTS-CTS is so covered, and if so,
how.

This information is being sought on behalf of the IEEE-P1174 standards
committee.  P1174 is an outgrowth of IEEE-488.  IEEE-488 is also known
as GPIB or General Purpose Instrument Bus.  (IEC-625 is the equivalent 
international standard).  P1174 is an effort to standardize the control
of test and measurement instruments using RS-232 type interfaces.  (That
is, to use the IEEE-488.2 protocols over RS-232 instead of IEEE-488.1).


Jac Colby      jacc@tekig5.TEK.COM
Tektronix Inc  {ucbvax,decvax,pur-ee,cbosg,ihnss,hplabs}!tektronix!tekig5!jacc
PO Box 500  MS 47-704    Home: 5529 SW Patton Rd
Beaverton, OR, 97077           Portland, OR 97221
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