Subject: Re: Need jumper settings for M7940/8017
To: Carl Lowenstein <cdl@mpl.ucsd.edu>
From: Rick Copeland <rickgc@calweb.com>
List: port-vax
Date: 09/22/1998 14:07:01
I have checked the jumper on the DLV11 (M7940) for the "EIA" jumper and it
is disconnected, however the 40-pin berg connector may be a problem.  I
don't know what the pinouts are and I now know for sure that the DLV11 was
setup for current loop operation.  I need to know what those pins on the
40-pin berg connectors are so that I can build a cable for RS-232 operation.

Rick


>> I have a pair of serial cards (M7940 and 8017) that I need to configure to
>> RS232 from their current setup which I believe is a 20ma current loop.  The
>> cards are from a pdp 11/03 that I have removed from my Vax 11/785. If
>> someone has this infornatiom or knows of some Faq page where I can get
>> could you please post it?
>
>A quick tour through "Microcomputer Products Handbook" (1985) tells me
>the following:
>
>M7940 is otherwise known as DLV11.  It should have a jumper about 1/4 of
>the card length in from the handle end, approximately centered side-to-side,
>labeled EIA.  This will enable EIA (RS232) operation, assuming you have
>the proper cable to connect to the 40-pin Berg connector.  There are also
>four jumpers to the side of the 40-pin connector, labeled CL<1-4> which
>might have 180-ohm resistors present if the board was set up to be the
>active end of the current loop.  I don't think it hurts to leave them in,
>since the BC05C cable for RS232 doesn't connect to the current-loop pins
>on the Berg connector.
>
>M8017 is DLVE1 formerly known as DLV11-E.  Best I can tell, it is EIA only.
>It too needs the proper cable.  Presumably the same one as the DLV11.
>
>Pinout data for the BC05C is buried much deeper, probably with my 11/40
>documentation.
>
>    carl
>
>        carl lowenstein         marine physical lab     u.c. san diego
>        {decvax|ucbvax} !ucsd!mpl!cdl                 cdl@mpl.ucsd.edu
>                                                  clowenstein@ucsd.edu
>
>
Sincerely,
Rick Copeland
Information Systems Manager
InterMag, Inc.
(916) 568-6744 x36