From: Bruce Harvey (BruceH@ROUTESCAPE.COM)
Date: Mon Mar 03 2003 - 10:05:48 EST
How many wires are in the cables for the Null Modem and the Direct cables?
The 'DCE' Aux port should use a direct cable, and as such, you may be using
an old printing cable that has all 25 lines pulled, providing all of the
necessary signals. The null modem cable may only have transmit, receive,
and ground (albeit with Tx and Rx reversed somewhere along the line), but
the host needs what's known as a 'full' null-modem cable (not really full,
but you'll see below). Here is the pinout of that cable, assuming a
'25-pin' D-shell type connector:
2 --------- 3
3 --------- 2
4 --------- 5
5 --------- 4
6 --------- 20
|
8
7 --------- 7
20 -------- 6
|
8
This translates to:
Tx --------- Rx
Rx --------- Tx
RTS --------- CTS
CTS --------- RTS
DSR --------- DTR
|
DCD
Gnd --------- Gnd
DTR -------- DSR
|
DCD
(I may have CTS and RTS reversed ... it's been a while ;-). Note that both
DSR (DataSetReady) and DCD (DataCarrierDetect) are tied to the opposite's
DTR (DataTerminalReady). This is usually the biggest pain of creating
these cables. Standard IBM cables for this purpose should do this, but if
they're old cables, leads may have become broken, etc. Ask an old-timer how
to "ohm-out" a cable.
One more thing: Make sure the system port on the system using the Main port
is set up exactly the same as the one using the AUX port (since that's
operating correctly).
Should work after this, if all the equipment is in order. You might also
try adding (with the appropriate M-M or F-F adapters) the Null Modem cable
to the existing straight cable that works on the AUX ... and plugging that
whole thing into the Main port. If the cable is correct, it'll work.
----------------------------------
Bruce T. Harvey (Special Projects)
----------------------------------------
bth@comcast.net -- bruceh@routescape.com
410-236-5721 (cell) -- 410-403-2390 (off.)
-------------------------------------------
Insight Distribution Systems / CoAxis, Inc.
Hunt Valley, Maryland U.S.A. 21031-1422
-------------------------------------------
-----Original Message-----
From: Webb, Eric [mailto:EWebb@COOPERLIGHTING.COM]
Sent: Monday, March 03, 2003 9:40 AM
To: aix-l@Princeton.EDU
Subject: [aix-l] Using the two ports on an IBM 3153 terminal
I have an IBM 3153 that I'm trying to use as a serial console for two
headless machines. The 3153 has an "AUX" and an "EIA" port. According to
its manual, one is
DTE, one is DCE, but you can supposedly use both for serial terminals (one
just needs a null modem adapter, the other doesn't).
Well, I have one machine working on the AUX port with a null modem adapter.
The
other port, no matter what I try, just doesn't seem to do anything. At this
point, I don't suspect the terminal itself, I'm still thinking it's an
RS-232
issue.
Any ideas??
Eric
This Email and any files transmitted with it are confidential and intended
solely for the use of the individual or entity to whom they are addressed.
If you have received this Email in error please notify the system manager.
Please note that any views or opinions presented in this Email are solely
those of the author and do not necessarily represent those of the company.
Finally, the recipient should check this Email and any attachments for the
presence of viruses. The company accepts no liability for any damage caused
by any virus transmitted by this Email.
This archive was generated by hypermail 2.1.7 : Wed Apr 09 2008 - 22:16:37 EDT