DB9 Alternatives

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I'm looking for an alternative connector for a serial port.
I HATE the way the DB9 connector looks, but still want to do serial
traffic over 5-10 feet.
My app would have say a 100 devices and they need connect to a central
hub of sorts.
I definately need something that can lock to the device (i.e. RJ45
click, BTW USB is out because I'm dealing with only serial traffic, and
USB doesn't have a clickable connector)
RJ45 is an alternative but I'm interested in seeing other options.

Any suggestions?
Thanks.


Re: DB9 Alternatives

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Is size an issue as well as the secure locking of the connector to the
device?

I have, in the past, used the Nuetrik XLR 6 pin for serial data-comms.
These are very robust connectors and able to withstand quite a bit of
maltreatment. If these are too large, then you may find some mini-din's
(about the same size as the PS2 connectors) which are latchable. Not as
robust but also a reasonable choice.

--
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Re: DB9 Alternatives
Yes size is an issue, RJ45 is a pretty decent size.
saw the Nuetrik XLR ones, boy they are expensive!

I don't want to spin my own cables for sure. it's quite amazing that
there aren't too many alternatives to the DB9 (ahem.. DE9!!)


Re: DB9 Alternatives
On Friday, in article

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There are various methods of locking D type connectors from slide locks
to screws and even retaining clips.

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The PS2 connector *IS* a 6 pin Mini DIN, just like a SVHS connector *IS*
a 4 pin Mini DIN. They are just normally non latching versions. The pins in
Mini DIN connectors are a bit fragile and if making your own cables by
using solder variants watch the iron temperature the nylon is easily
meltable.

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: DB9 Alternatives
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What is commonly called a "DB9", isn't a DB9.  It's actually a
DE9.  The DB form factor is the size that DB25 connectors have!

Regardless, there are DE9 connectors that lock.  They are
perhaps not as convenient as an RJ45, so if you are commonly
changing these cords they definitely are not desireable.

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You might want to consider using RJ45 with USB though...

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20 years ago the AT&T 3B2 computers had serial port cards with
32 ports, all using RJ45 connectors.  It was common then to use
RJ45 to DB25 converters.  Regardless, the point is that what you
are considering is something which has been done, and worked
well.

Note that you do *not* want to use twisted pair cable for RS-232
signals if the length and/or speed is at all significant.  With
short cables less than 10 feet, it would not be a problem; but if
you have an odd one here or there that is 100 feet long, find some
8 conductor "flat satin" cable that is not twisted.

--
Floyd L. Davidson           <http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)                         snipped-for-privacy@apaflo.com

Re: DB9 Alternatives
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And here I thought I might be the only person left who knew that <g>.
I've tried for years to persuade coworkers to simply refer to a "D9", as
a less offensive alternative to the incorrect "DB9".

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It might help to know what the OP means by not liking "the look" of the
DE9. In the many years that small connectors have been designed, the D
series remains one of the best all-around solutions, being reasonably
robust, inexpensive, and relatively small for their pin count.

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As good as they are for Ethernet use, for some reason, my experience
with them in serial comms has not been all that good. For some reason,
they have been less reliable.


Bill

Re: DB9 Alternatives
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Interesting. In the past, I've equipped several of my sites with RJ45 based
terminal servers, used to connect DEC MMJ-based terminals, and making up my
own leads. I never experienced any real problems, but I wonder now if I was
lucky. What type of problems did you encounter ?

To the OP: The MMJ connector referenced above is a 6 pin RJ45 style (but a
bit smaller) locking connector, but it's probably obsolete by now.

Simon.

--
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP      
Microsoft: The Standard Oil Company of the 21st century

Re: DB9 Alternatives
On 22 Jul 2005 20:18:04 -0500,

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AFAIK the 6-pin RJ45 is a RJ12 connector. My experience is that where
small size was an issue for EIA-232 comms, RJ12 connectors was used.
The pin-outs are normally:

1    RX
2.    CTS
3    GND
4    GND
5    RTS
6    TX

Hence by crimping the connector on the other side of the cable, One
gets Rx connected to Tx etc.

Also by using an RJ12 in stead of RJ45, people wont plug your wire
into an ethernet port. They might plug it into a telephone wall socket
though.

Regards
  Anton Erasmus

Re: DB9 Alternatives
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But that is taken care of by having the GND on 3 and 4, where the telephone
signals are :-)

Meindert



Re: DB9 Alternatives
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Interesting! So what do DA, DC, DD, etc look like?



Re: DB9 Alternatives
On Fri, 22 Jul 2005 21:25:28 GMT, "Daniel Berglund"

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In the "standard density" connectors, a DA shell holds 15 contacts, DB
holds 25, DC is 37, and DD is 50.  DE (perhaps an afterthought?) holds
9 contacts.  The A, B, C and E shells are all the same width, but vary
in length, and have two rows of contacts.  The D shell is about the
same length as the C, but is wider, with three rows of contacts.

There is a High Density E-size connector with 15 contacts, used on
computer monitors.

Cannon (who I think originated this family) also make a Double Density
series - the DA shell holds 31 contacts.

There are some variations that can have high current or coax contacts
- the A shell can have 3 of these contact.


--
Peter Bennett, VE7CEI  
peterbb4 (at) interchange.ubc.ca  
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Re: DB9 Alternatives
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Well, actually it is a little confused.  The DA/DB/DC/DD/DE
indicates the length, while the number is how many pins there
are.

Originally there was a DA-15, DB-25, and a DC-37, each being
longer than the other, but the pins all have the same spacing.
(Note that you'll see DA-15 connectors for joy sticks, but
DC-37's are not so often seen.)  There originally was also a
DD-50, but that has three rows of pins, so it looks a little
different.

The DE-9 seems to be an addon that came later.

There are others too (svga video connectors e.g.).

--
Floyd L. Davidson           <http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)                         snipped-for-privacy@apaflo.com

Re: DB9 Alternatives

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No kidding, I have been in the computer business as a techie for $25+ years
and never knew that. I have learned something today. This is big news in my
life because I come in contact with lots of connectors and always want to
know the correct names.

examples:

DE15HD = vga
RPTNC = linksys router antenna port



Re: DB9 Alternatives
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For nearly full generality you need the 9 runs of copper.  Send,
Rcv, 2 supervision each way (rts, cts, dtr, cd), ring, common, and
protective ground.  Some of the mini-DINs should be useful, but do
you really want to build your own cables?  Also see what is in a
TelCo supplies catalog.

--
Chuck F ( snipped-for-privacy@yahoo.com) ( snipped-for-privacy@worldnet.att.net)
   Available for consulting/temporary embedded and systems.
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Re: DB9 Alternatives
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Generally, he won't need a Protective Ground on cables 5-10 feet
long.  Likewise the Ring line can often be left out, and
depending on the application the CD and DTR lines can be
combined.  Not to mention that hardware flow control may or may
not be needed.

A universal cable pretty much needs 9 pins; but most specific
applications don't.

--
Floyd L. Davidson           <http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)                         snipped-for-privacy@apaflo.com

Re: DB9 Alternatives
Maybe a DIN connector.  It would sure make the Mac customers happy.  We used
one on a product a while back because of similar space issues.  It worked
out well for us and wasn't too costly.

Good Luck

Scott

Re: DB9 Alternatives
I like Molex C-Grid connectors - small, inexpensive and with a really
convincing click when they engage

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Re: DB9 Alternatives
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This may be of interest regarding RJ-45:
http://yost.com/Computers/RJ45-serial /

Richard

Re: DB9 Alternatives
Bit of history. :-)
The Sinclair QL used a phone line like connector for its serial port, it
worked rather well.
The 68K Mac's (And some Amiga upgrades) used a Mini-Din like connector for
the serial port.
Both of these had cheap adapters to convert them back to the DE9 connector
if needed.



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