Re: RS-232 to RJ45 adapters?

Dave Carmean (dlc@silcom.com)
Sat, 8 Jun 1996 00:51:30 -0700 (PDT)

In a previous message, Jon Lewis wrote:
>
> On Fri, 7 Jun 1996, Greg Mead wrote:
>
> > I've noticed many of you mention using RS-232 to RJ45 adapters to wire your
> > PortMasters. I've been pricing them, and the cheapest I can find them (even
> > in bulk) is around $4/ea. Is that a reasonable price for them? I thought
> > somone
> > said they were $2 or less earlier. Anyone wanna share their source? :) Thx
>
> South Hills: $8 each
> Graybar: $3.50 each
> "little electronis catalog I just got and can't recall the name of":
> $1.50 each
>
> I bought 10 from this last place just to try out, and have not yet had
> time to figure out the pinouts...no docs included. When I ordered, I was
> told they move these by the thousands a day, which was why they were able
> to offer such low prices. These even have thumb screws.

I posted a URL yesterday, but neglected to mention cost....

Roger's Systems Specialist
21021-504 Soledad Cyn. Rd.
Santa Clarita, CA 91351 USA
(800)-366-0579

TE-5M8 DB25 male to 8 cond RJ45 1.50 ea
<http://www.rogerssystems.com/Catalog/RSCAT12.GIF>

TE-MC8 RJ-45 Flat Cable modular plug .09 ea
<http://www.rogerssystems.com/Catalog/RSCAT17.GIF>

Get a few insert/extract tools while you're at it :o)

TM-303. $2.00 ea.

Now, about pinouts....take a look at this page on the "Yost" method....

<URL:http://www-scf.usc.edu/~khendric/info/yost.html>

One of the pictures is scanned from Nemeth, et. al, _Unix System
Administration Handbook_, so I assume that's where he got the info from.

(Ack...never know how to cite books in email :o).

Basically, you wire these adapters for either DTE or DCE use, and
torque them onto the equipment...they stay there. Then you use a
standard 8-cond phone cable (mirror-image ends) to connect them.

My only beef is that it leaves out DSR in favor of having both center
pins be signal ground. But they've included DTR....this doesn't
make sense to me, and it also didn't work. I ditched one of the redundant
ground pins and put DTR there instead.

'Course in this application, you could wire all the hoods the same and
use a straight-through cable to the modem, since it's DTE to DCE, but
I think that if I'm gonna build the hoods and they're staying on the
equipment, it's easier to have just one kind of phone-type cable laying
around.

-- 
David Carmean		WB6YZM		DC574		<dlc@silcom.com>
	System/Network Administration, Silicon Beach Communications
Unsolicited commercial e-mail not accepted.  Violators will be prosecuted.