On 17 Nov 2005 08:57:20 -0800, "jd_hupp" put
finger to keyboard and composed:

I have a Brother IntelliFAX 2400ML (model PPF-2400ML) with a jack on
the back labeled PC I/F. It supports an optional kit called the
Missing Link, part number PCI-1, which allows you to use this
fax/copier for printing and scanning as well. That kit number (PCI-1)
also seems to be referred to as the Multi-Function Link with Brother's
Multi-Function Center line of products.

I have the updated version of the software (Y2K compliant and
supporting Windows 95/98/Me and maybe 2000), and I want to build the
cable from on-hand materials or use a rare-but-standard cable. (This
old machine works and I'd like to expand its abilities, but it is not
worth putting more than a few dollars into.)

I have been able to learn that the OEM cable has a DB25 plug on one end
and attaches to the computer's serial port (the kit also includes a
DB-25 to DB-9 adapter). On the end that attaches to the Brother's PC
I/F jack, it is an 8-pin module, the same as a network RJ-45 plug. (Is
there an RJ-8 specified for serial communications?)

There are apparently some standards for connections like this, if
Brother decided to use them and not do something proprietary. RS232
candidates:
EIA/TIA 574 (RS-232 ) Defines RS232 with DB9 connectors
EIA/TIA ??? (RS-232C) Defines RS232 with DB25 connectors
EIA/TIA 561 (RS-232D) Defines RS232 with RJ45 connectors ("8 position
modular connector")

I tried connecting fax to computer with a couple old AT&T phone
equipment adapters/cables that are 8-pin modular on one end and DB25 on
the other, but the Missing Link software did not see the fax over those
connections. I don't know how those AT&T pieces are wired.

Does anyone know anything more about this cable?

I'm not familiar with this setup, but I would start by measuring the
voltages on each RJ45 pin. This will tell you which pin is an output
(+12V or -12V) and which is an input (0V). A continuity test would
also identify signal ground.

-- Franc Zabkar

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