I used to buy what we called "Octopus Cables" from modem racks
to DTC/48s about 10 years ago.  Such an item with about 16 ATP plugs
cost me about $400 (USDollars)  I imagine such an item now is about
$800.  They're probably cheaper with DB-25 connectors.

(But heck, that would still be cheaper than 10 HP cables!)

They're still in business at (copied from their web page):

CABLE EXCHANGE
13921 Seaboard Circle Garden Grove, CA 92643

714-554-4370 FAX 714-554-0428 (800)-422-2539

E-Mail us at: [log in to unmask]

Tracy M. Johnson
TRW Automotive Electronics

> -----Original Message-----
> From: Patrick Santucci [mailto:[log in to unmask]]
> Sent: Monday, January 17, 2000 2:13 PM
> To: [log in to unmask]
> Subject: Any modem cable experts out there?
>
>
> Listers:
>
> We're trying to save some money (so what else is new?) and not have to
> spend $90 each for HP's 40233A modem cables (we need 32 of them) to
> connect a rack of modems to some DTC ports (DTC16 with MDP ?Modem
> Distribution Panel? expansion ports). So we made some cables
> wired like
> the 40233A cable, and we're trying to make them work.
>
> We have *one* HP 40233A cable, which works: we can connect
> via modem to
> the DTC and get a system prompt. But when we use the same
> modem and the
> same DTC port with the cables we built, the modem answers and then
> immediately disconnects.
>
> Strangely, the OpenView DTC MGR reports that the MDP ports
> are good, i.e.
> Board Status shows the ports as green. When we used the wrong cable,
> 92219Q, the ports showed up red. If we reverse the ends of
> the cable and
> plug the Modem end into the DTC port (like we accidentally did on one
> cable, oops), it also shows up red. So I don't think it's the
> DTC that's
> disconnecting us, but I could be wrong.
>
> Here are the cable specs from HP's DTC Racking & Cabling
> Guide (mfg # 5961-6410,
> order # 5961-0373), page 58:
>                  *  *  *  *  *  *
> RS-232 Connection to modems
> This cabling scheme is recommended for connecting modems to a DTC.
> Existing HP cable: HP 40233A
>
> 25-pin male connector             25-pin male connector
>        to DTC                            to modem
> ---------------------             ---------------------
>  1 - PGND    -         ---------   1 - PGND    -
>  2 - RD      INPUT     <--------   3 - RD      OUTPUT
>  3 - TD      OUTPUT    -------->   2 - TD      INPUT
>  4 - DCD     INPUT     <--------   8 - DCD     OUTPUT
>  5 - GPO     OUTPUT
>  6 - DTR     OUTPUT    -------->  20 - DTR     INPUT
>  7 - SGND    -         ---------   7 - SGND    -
>  8 - RTS     OUTPUT    -------->   4 - RTS     INPUT
>  9 - RI      INPUT                22 - RI      OUTPUT
> 20 - DSR     INPUT     <--------   6 - DSR     OUTPUT
> 22 - CTS     INPUT     <--------   5 - CTS     OUTPUT
>
> Note: the DTC does not monitor the RI signal from the modem.
>                  *  *  *  *  *  *
> You will notice that, while several pairs cross (2-3, 4-8,
> 6-20), others
> go straight through (1-1, 7-7) and still others have pins with no
> corresponding match at the other end. This is the way the cable is
> supposed to be, according to HP.
>
> So why doesn't it work??? The only difference that is readily
> apparent is
> that the connectors on the cables we built have all 25 pins,
> even though
> they aren't wired, whereas the HP cable only has the pins it actually
> uses. But that wouldn't cause this behavior, would it? Or could it?
>
> Getting desperate,
> Patrick
> --
> Patrick Santucci
> Technical Services Analyst
> Seabury & Smith, Inc.
>
>