serial pinout 1550

Dirk Wetter dirkw at rentec.com
Fri Oct 5 10:30:00 CDT 2001


On Fri, 5 Oct 2001, Michael E Brown wrote:

> Thanks Glen! Very informative.

yes, agree!!! thx very much, glen!

> --
> Michael
>
> On Fri, 5 Oct 2001, Glen Turner wrote:
>
> > Dirk Wetter wrote:
> > >
> > > we bought a cyclades terminalserver (nice piece btw, running Linux ;)
> > > and we wanted to use that to get console access to the new 1550s
> > > we bought. we have trouble however finding docu about the DB9 pinout
> > > of the 1550. can anybody help me out ?
> >
> > As Michael pointed out, the 2550 has a RS-232 port
> > with the same proprietary pinout as used on the
> > IBM PC/AT and its many, many successors.

yes, this is also what i figured by trial and error, but the 1550 is
different from the 2550 for some reason, at least i cannot use the same
connector:

using a xyplex/rocket port/cisco terminalserver i can use for the 2550
i can use the same home made connector as i am using e.g. for sparcs and
other PCs. with a 1550 i have to use a home made different connector to get
it working, the wiring is kind of strange, really.

using a cyclades and a 1550 however i found out yesterday that i can use
the standard connector as i am e.g. using for the 2550 and a cisco
tserver e.g.

> > The Cylades RJ45 connector is documented at
> >   http://www.cyclades.com/solutions/techtalk/techtalk15.htm
> > There is no standard for RS-232 over RJ-45 structured
> > cabling, so each manufacturer uses differing pins.

yep! another great thing with the cyclades is the good documentation!

> > Based on that web page, you want a cable with the
> > pinout
> >
> >      Cyclades RJ45        IBM PC/AT
> >      4 SGnd -------------- SGnd 5
> >      3  TxD -------------- RxD  2
> >      6  RxD -------------- TxD  3
> >      1  RTS -------------- CTS  8
> >      5  CTS -------------- RTS  7
> >      2  DTR -----------+-- DCD  1
> >                        |
> >                        +-- DSR  6
> >      7  DCD --+----------- DTR  4
> >               |
> >      8  DSR --+
> >
> > Which is Cyclades part CAB0036.  Alternatively, you
> > can get it manufactured by one of the many speciality
> > cabling businesses.  Personally, I'd choose to make
> > my own, using a pin crimping tool, as cables made to
> > length give much better system reliability.
> >
> > I'd strongly suggest using shielded cable, as one character
> > of line noise during boot can make the Dell 1550 BIOS
> > hang about forever (as it enters the BIOS settings
> > screen and waits for further keystrokes).  I'm not sure
> > if the 2550 has the same bug.

i never experienced that. the only thing with the 1550 is that i had
to get a bios >A04 and disable the "serial" definition in
lilo.conf. have you tried standard cat5 cables and do the wiring in
the db9 or db25 connectors?

> > For more information on serial consoles see the draft of an updated
> > Remote-Serial-Console-HOWTO at
> >
> > http://www.aarnet.edu.au/~gdt/serialconsole/Remote-Serial-Console-HOWTO/

great, thx for the work!

> > This is currently going through the process of being accepted by
> > the Linux Documentation Project and should be released in a few weeks.
> >
> > Feedback on the HOWTO is welcomed, particularly before the release
> > of the document :-)

i think i might have something to contribute. ;-)


cheers,
	~dirkw


-----------
Dirk Wetter
Renaissance Technologies/NY





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