Re: Alpha DB9 to DECserver RJ45 cable?

From: John Santos (john_at_egh.com)
Date: 09/29/05 

Date: Thu, 29 Sep 2005 00:49:48 GMT

Bob Kaplow wrote:
> I need to connect the console of my new DS25 to a DS700 terminal server for
> remote console access. In the past I've used an H8571-J DB9 to MMJ adapter
> and the BN24H cable, or the H8571-J to a BC16E cable to an H8584-AC adapter.
>
> Is there an appropriate adapter that will work with a standard (or
> crossover) network cable? Is the H8584-AC what I'm looking for?
>
> I did find a bunch of DB9F to RJ45 adapters, that aren't DEC/HP and are
> labeled "terminal" and "74-0495-01" but they don't seem to work either with
> a straight or crossover network cable. Any one know what this part is for?

I had a similar problem, and lots of trouble tracking down the
right adapters, so I ended up making them.

I wanted to hook the console ports of some MSA1000's to a DS90 server.
This might match your config.

The MSA1000 has a special cable that terminates in a DB9F suitable for
plugging into a PC serial port, that also works fine with a serial port
on an ES40 (using $ Set host/dte or Kermit.)

Unfortunately, there were 4 MSA1000's (two dual-redundant pairs) and
only one available port on the ES40 (serial console on the other one),
but there is a DS90 with a bunch of free ports.

The DS90 has 8-pin RJ45 jacks. They seem the same as the jacks on the
16-line (no modem control) version of the DS700.

The ES40, DS90 and MSA1000's are at a remote site, so I simulated
the whole thing with a DS700, a modem with a standard PC-style 25-pin
to 9-pin cable (the 9-pin end normally intended to plug into a PC
serial port, and a straight-through Ethernet patch cable.

I got some DB9M to RJ45F adapters (the kind where you plug the pins
into the holes in the 9-pin end to wire it up as desired.) I cleaned
out the local computer store (MicroCenter) and got a big bag more
of them at a local electronics store (U-Do-It in Needham, if anyone
is local to the Boston Mass area), and they were wired and color-coded
the same, even though they were different manufacturers. The U-Do-It
ones are Philmore Interface Adaptor RJ45, 8 cond, Female to DB-9 Male,
no 70-084-10.

This is how I wired the pins

RJ45 DB9

2 Orange -> 2 Rcv data
4 Red -> 8 CTS
5 Green -> 7 RTS
6 Yellow -> 3 Tx data
7 Brown -> 4 DTR
8 White -> 6 DSR

This leaves pin 1 (DCD) and Pin 9 (???) on the DB9 unused and the two
grounds (pin 1 Rcv gnd and pin 3 Tx gnd) on the RJ45 end and one ground
(pin 5 Gnd) on the DB9 end.

One of the modems I was testing with wanted Rcv Gnd (1, blue) connected
to pin 5 and the other one would only work with Tx Gnd (3, black)
connected to pin 5 on the DB9. (Both USRobotics, one a Sportster
and the other was a Courier!)

I ended up snipping of the pin on one of the wires and soldring the
stub to the middle of the other one (shorting the two grounds), which
worked with both modems.

So:

1 Blue ----|
            |-----> 5 Gnd
3 Black ---|

This plus a straight-through Ethernet patch cable, worked with an
MSA1000. Don't know if it will help with your DS25. You may have
to create a null-modem by swapping Tx and Rcv, RTS and CTS, and
DTR and DSR. A DB9 breakout box would help here, but I don't have
one. (I did use a DB25 breakout box between the DB25 connector and
the modem to help debug mine.)

HTH 

-- 
John Santos
Evans Griffiths & Hart, Inc.
781-861-0670 ext 539

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