Path: utzoo!attcan!uunet!vsi!friedl
From: friedl@vsi.UUCP (Stephen J. Friedl)
Newsgroups: comp.dcom.modems
Subject: Re: null modem cables
Summary: frame grounds
Keywords: sparks loud noises flashes of bright light
Message-ID: <837@vsi.UUCP>
Date: 10 Sep 88 04:34:30 GMT
References: <8809030943.AA02215@ucbvax.Berkeley.EDU> <2066@stpstn.UUCP> <829@sceard.UUCP>
Organization: V-Systems, Inc. -- Santa Ana, CA
Lines: 23

In article <2066@stpstn.UUCP> aad@stpstn.UUCP (Anthony A. Datri) writes:
<
< [building a null-modem cable]
<
< 1---------1  (always friendly to include the frame ground)
<

In article <829@sceard.UUCP>, mrm@sceard.UUCP (M.R.Murphy) writes:
<
< Including the 1-1 connection can really be exciting if someone (electrician,
< homeowner, facilities group, ...:-) has miswired the AC and reversed
< hot and neutral somewhere. The 1-1 connection can then become a fuse.
< It's not always a good thing to connect frame-frame.

I believe at one time the National Electrical Code said that wiring
1 <---> 1 is a violation of code for this reason.  Logic ground is
fine with pin seven, but a 32-gauge wire is not sufficient to provide
a safe frame ground.  Anybody know if this is still the case?

-- 
Steve Friedl    V-Systems, Inc.  +1 714 545 6442    3B2-kind-of-guy
friedl@vsi.com     {backbones}!vsi.com!friedl    attmail!vsi!friedl
------------Nancy Reagan on conductance: "Just say mho"------------