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wiring for apc ups cables smart ups
© December 2004 (various authors)
uninterruptible power supply

Ahh, the good old days. I think almost all modern UPS's have either USB or network ports, so worrying about pinouts shouldn't be an issue.

However, if you should find yourself stuck with something that can't do either of those, Jeff's diagrams will get you set.

From: Jeff Liebermann <jeffl@comix.santa-cruz.ca.us>
Newsgroups: comp.unix.sco.misc
Subject: APC UPS Cable wiring
Message-ID: <7mq3psorp41p5lve4nkbemr125hckg6pbj@4ax.com> 
Date: Wed, 09 Aug 2000 16:48:18 -0700

It's another day in UPS hell.  For the zillionth time, I find yet
another APC UPS, plugged into yet another server, wired with yet
another straight thru 9 pin cable, which absolutely does NOT work.
Once again, I dragged out my trusty D-connector crimping kit and built
yet another APC UPS cable.

For the benifit of those that screwed up in the same manner, and
didn't want to spend their profit margin on the approved APC cables,
here is the reverse engineered wiring diagram.  Let the crimping

Smart UPS 940-0024B (black cable)
Use with "advanced" signaling.

        DE9S            DE9P
          PC             UPS
     /--1      /--->------1
        3----/            3
        4                 4
        5----\            5
        6     \           6
        7--\   \          7
        8--/    \         8
        9        \--------9 gnd

BackUPS 940-0023A  (grey cable)
Use with "basic" signaling.

        DE9S            DE9P
          PC             UPS
        1------\          1
        2       \---------2
        3                 3
        4             /---4
        5-------------*   5
        6             |   6
        7             |   7
        8             |   8
        9             \---9 gnd


Note that with the black "advanced" cable, and a Smart UPS, and the
overpriced SNMP management adapter, you can configure and upgrade the
adapter from a serial port and a terminal emulator.  The trick is to
start at 2400 baud N81.  You can change the baud rate from the menus,
but 2400 is the starting default.

# Jeff Liebermann   150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice
# 831.426.1240 fax     https://www.cruzio.com/~jeffl
# 831.421.6491 digital_pager   jeffl@comix.santa-cruz.ca.us

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