Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site fritz.UUCP
Path: utzoo!watmath!clyde!cbosgd!ihnp4!qantel!hplabs!felix!fritz!zemon
From: zemon@fritz.UUCP (Art Zemon)
Newsgroups: net.dcom,net.periphs
Subject: Ringing RS-232 dilemma
Message-ID: <4134@fritz.UUCP>
Date: Tue, 12-Nov-85 15:53:02 EST
Article-I.D.: fritz.4134
Posted: Tue Nov 12 15:53:02 1985
Date-Received: Thu, 14-Nov-85 08:04:22 EST
Reply-To: zemon@fritz.UUCP (Art Zemon)
Organization: FileNet Corp., Costa Mesa, CA
Lines: 20
Xref: watmath net.dcom:1459 net.periphs:903

Sender:


For various reasons I have a RS-232 line which is sometimes
connected to another computer and sometimes left just hanging.
When it is connected all is fine.  When it is disconnected, the
line "rings" and my VAX is inundated with ~1000 characters per
second input.  Poor Felix (the VAX) tries to echo all those
characters and the poor human users complain about a certain
lack of responsiveness.

Is there some device which can be placed in the line to prevent
the ringing but will not interfere with normal operation?  We
tried placing 10K resistors between pins 2 and 7 and between 3
and 7 but this didn't help.

As an alternative, is there a passive device into which we can
plug the line when it is disconnected from the computer?
-- 
	-- Art Zemon
	   FileNet Corp.
	   ...! {decvax, ihnp4, ucbvax} !trwrb!felix!zemon