Strange RS232 Wiring

C

Costas Vlachos

Guest
Not exactly a design question, but I thought some of you may be able to
help. I've just bought a USB-to-RS232 converter cable for my laptop and it
came with a weird 9-pin FEMALE to 9-pin MALE adapter. I initially thought it
was a null-modem adapter, but upon examination it uses the following wiring
which I've never seen before:

FEMALE MALE

PIN 1 o----+ +---------o PIN 1
| |
PIN 2 o--- | ---+ | PIN 2
| | |
PIN 3 o--- | -- | ---+ | PIN 3
| | | |
PIN 4 o--- | -- | -- | ---+ PIN 4
| | | |
PIN 5 o--- | -- | -- | -- | ---+ PIN 5
| | | | |
PIN 6 o----+ | +--------------o PIN 6
| | |
PIN 7 | | +----o PIN 7
| |
PIN 8 o-------- | --------+ PIN 8
|
PIN 9 +-------------------o PIN 9

CASE o-----------------------------o CASE

Note that pins 2 and 3 (TxD, RxD) are not used at all in the MALE side! The
adapter has the label "NBT/BT" on it. There is no mention about it in the
box or manual. I Googled about it but nothing relevant came up... Any ideas
on what this wiring is for?

Many thanks.

Costas
_________________________________________________
Costas Vlachos Email: c-X-vlachos@hot-X-mail.com
SPAM-TRAPPED: Please remove "-X-" before replying
 
Costas Vlachos wrote:
Not exactly a design question, but I thought some of you may be able to
help. I've just bought a USB-to-RS232 converter cable for my laptop and it
came with a weird 9-pin FEMALE to 9-pin MALE adapter. I initially thought it
was a null-modem adapter, but upon examination it uses the following wiring
which I've never seen before:

FEMALE MALE

PIN 1 o----+ +---------o PIN 1
| |
PIN 2 o--- | ---+ | PIN 2
| | |
PIN 3 o--- | -- | ---+ | PIN 3
| | | |
PIN 4 o--- | -- | -- | ---+ PIN 4
| | | |
PIN 5 o--- | -- | -- | -- | ---+ PIN 5
| | | | |
PIN 6 o----+ | +--------------o PIN 6
| | |
PIN 7 | | +----o PIN 7
| |
PIN 8 o-------- | --------+ PIN 8
|
PIN 9 +-------------------o PIN 9

CASE o-----------------------------o CASE

Note that pins 2 and 3 (TxD, RxD) are not used at all in the MALE side! The
adapter has the label "NBT/BT" on it. There is no mention about it in the
box or manual. I Googled about it but nothing relevant came up... Any ideas
on what this wiring is for?

Many thanks.

Costas
Click to expand...
It looks like they got a connector mirrored on their board, then fixed
it with the weird connector rather than pitching the stuff and starting
over again.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
 
On Mon, 14 Mar 2005 17:33:43 +0000 (UTC), "Costas Vlachos"
<c-X-vlachos@hot-X-mail.com> wrote:

Not exactly a design question, but I thought some of you may be able to
help. I've just bought a USB-to-RS232 converter cable for my laptop and it
came with a weird 9-pin FEMALE to 9-pin MALE adapter. I initially thought it
was a null-modem adapter, but upon examination it uses the following wiring
which I've never seen before:

FEMALE MALE

PIN 1 o----+ +---------o PIN 1
| |
PIN 2 o--- | ---+ | PIN 2
| | |
PIN 3 o--- | -- | ---+ | PIN 3
| | | |
PIN 4 o--- | -- | -- | ---+ PIN 4
| | | |
PIN 5 o--- | -- | -- | -- | ---+ PIN 5
| | | | |
PIN 6 o----+ | +--------------o PIN 6
| | |
PIN 7 | | +----o PIN 7
| |
PIN 8 o-------- | --------+ PIN 8
|
PIN 9 +-------------------o PIN 9

CASE o-----------------------------o CASE

Note that pins 2 and 3 (TxD, RxD) are not used at all in the MALE side! The
adapter has the label "NBT/BT" on it. There is no mention about it in the
box or manual. I Googled about it but nothing relevant came up... Any ideas
on what this wiring is for?

Many thanks.

Costas
Click to expand...
I bought several adapters like below cheap and they don't work as
far as I can tell. The incorrect connector should have a warning
sign. The CD that comes with it looks somewhat homemade. I've got
another adapter that looks similar but with the correct
connector and it works great. Beware of the type below with the
attach screws!

http://store1.yimg.com/I/cputopiaonline_1834_8847806
 
"Si Ballenger" <shb*NO*SPAM*@comporium.net> wrote in message
news:423617a2.101521520@news.comporium.net...
I bought several adapters like below cheap and they don't work as
far as I can tell. The incorrect connector should have a warning
sign. The CD that comes with it looks somewhat homemade. I've got
another adapter that looks similar but with the correct
connector and it works great. Beware of the type below with the
attach screws!

http://store1.yimg.com/I/cputopiaonline_1834_8847806
Click to expand...

I had a similar experience. I bought one like in your picture from eBay and
it didn't work. Was recognised by the system as a COM port, but there were
no signals coming out of the serial connector! I contacted the seller who
then sent me a different one which looks similar but without the thumb
screws. This one works perfectly with no problems at all. As to the purpose
of the "NBT/BT" adapter that came with it (wiring in my original message), I
still don't know what it's for. The cable works fine without it.

--
Regards,
Costas
_________________________________________________
Costas Vlachos Email: c-X-vlachos@hot-X-mail.com
SPAM-TRAPPED: Please remove "-X-" before replying
 
On Tue, 15 Mar 2005 00:05:03 +0000 (UTC), "Costas Vlachos"
<c-X-vlachos@hot-X-mail.com> wrote:

"Si Ballenger" <shb*NO*SPAM*@comporium.net> wrote in message
news:423617a2.101521520@news.comporium.net...

I bought several adapters like below cheap and they don't work as
far as I can tell. The incorrect connector should have a warning
sign. The CD that comes with it looks somewhat homemade. I've got
another adapter that looks similar but with the correct
connector and it works great. Beware of the type below with the
attach screws!

http://store1.yimg.com/I/cputopiaonline_1834_8847806


I had a similar experience. I bought one like in your picture from eBay and
it didn't work. Was recognised by the system as a COM port, but there were
no signals coming out of the serial connector! I contacted the seller who
then sent me a different one which looks similar but without the thumb
screws. This one works perfectly with no problems at all. As to the purpose
of the "NBT/BT" adapter that came with it (wiring in my original message), I
still don't know what it's for. The cable works fine without it.
Click to expand...
Same here, no signal on the tx line. Bought it from
www.compgeeks.com. Below is the type that works well.

http://tinyurl.com/63tto
 
In article <d158rf$346$1@sparta.btinternet.com>,
"Costas Vlachos" <c-X-vlachos@hot-X-mail.com> wrote:

I had a similar experience. I bought one like in your picture from eBay and
it didn't work. Was recognised by the system as a COM port, but there were
no signals coming out of the serial connector! I contacted the seller who
then sent me a different one which looks similar but without the thumb
screws. This one works perfectly with no problems at all. As to the purpose
of the "NBT/BT" adapter that came with it (wiring in my original message), I
still don't know what it's for. The cable works fine without it.
Click to expand...
Haha, I too bought a suspicously similar looking USB->RS-232 cable. Mine
worked intermittently but only with certain devices. I shelved it.

--
|\/| /| |2 |<
mehaase(at)sas(dot)upenn(dot)edu
 
On Tue, 15 Mar 2005 00:05:03 +0000 (UTC), "Costas Vlachos"
<c-X-vlachos@hot-X-mail.com> wrote:

"Si Ballenger" <shb*NO*SPAM*@comporium.net> wrote in message
news:423617a2.101521520@news.comporium.net...

I bought several adapters like below cheap and they don't work as
far as I can tell. The incorrect connector should have a warning
sign. The CD that comes with it looks somewhat homemade. I've got
another adapter that looks similar but with the correct
connector and it works great. Beware of the type below with the
attach screws!

http://store1.yimg.com/I/cputopiaonline_1834_8847806


I had a similar experience. I bought one like in your picture from eBay and
it didn't work. Was recognised by the system as a COM port, but there were
no signals coming out of the serial connector! I contacted the seller who
then sent me a different one which looks similar but without the thumb
screws. This one works perfectly with no problems at all. As to the purpose
of the "NBT/BT" adapter that came with it (wiring in my original message), I
still don't know what it's for. The cable works fine without it.
Click to expand...

Maybe the mystery connector fixes the bad USB->Serial adapter
that has no signals on the tx/rx?
 
In article <42363822.109840982@news.comporium.net>,
Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:

| Same here, no signal on the tx line. Bought it from
| www.compgeeks.com. Below is the type that works well.
|
| http://tinyurl.com/63tto

$1 each, $10 shipping. Bah! Why can't they just say $10 each, $1
shipping and be honest about it?

Do you know if Linux supports these?

Anybody know of an inexpensive USB to multiple serial ports (2 or 4 I
guess) device? (Yes, I know a hub and four of these things would work
too.)

--
Doug McLaren, dougmc@frenzy.com
"I can explain it for you, but I can't understand it for you." -Anon.
 
"Carl D. Smith" <cdsmith69NOSPAM@earthlink.net> wrote in message
news:ac4e319ek3hebdujgomgla4ubglfpivu5b@4ax.com...
Maybe the mystery connector fixes the bad USB->Serial adapter
that has no signals on the tx/rx?
Click to expand...

Yes, I thought that too and tried it with the faulty cable, but still no
joy... The mystery connector looks like a hand-made thing, with loose cables
soldered to the male/female ends, in a generic snap-on grey casing with a
small "NBT/BT" sticker on it. Weird stuff...

--
Regards,
Costas
_________________________________________________
Costas Vlachos Email: c-X-vlachos@hot-X-mail.com
SPAM-TRAPPED: Please remove "-X-" before replying
 
In article <42363822.109840982@news.comporium.net>,
Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:

| Same here, no signal on the tx line. Bought it from
| www.compgeeks.com. Below is the type that works well.
|
| http://tinyurl.com/63tto

$1 each, $10 shipping. Bah! Why can't they just say $10 each, $1
shipping and be honest about it?

Do you know if Linux supports these?

Anybody know of an inexpensive USB to multiple serial ports (2 or 4 I
guess) device? (Yes, I know a hub and four of these things would work
too.)

--
Doug McLaren, dougmc@frenzy.com
"I can explain it for you, but I can't understand it for you." -Anon.
 
Doug McLaren wrote:
In article <42363822.109840982@news.comporium.net>,
Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:

| Same here, no signal on the tx line. Bought it from
| www.compgeeks.com. Below is the type that works well.
|
| http://tinyurl.com/63tto

$1 each, $10 shipping. Bah! Why can't they just say $10 each, $1
shipping and be honest about it?

Do you know if Linux supports these?

Anybody know of an inexpensive USB to multiple serial ports (2 or 4 I
guess) device? (Yes, I know a hub and four of these things would work
too.)

Have a look at <http://www.ftdichip.com/>. There is a USB to dual UART
Click to expand...
device - you could put a few on a board with a hub chip. (I think that
the FTDI hub chip actually has a couple of serial ports on board already.)

http://ftdi-usb-sio.sourceforge.net/ has Linux drivers for some of the
FTDI devices. Think they're OK with the newer kernels.

Cheers

Matthew
 
On 17 Mar 2005 16:40:45 GMT, dougmc@frenzy.com (Doug McLaren)
wrote:

In article <42363822.109840982@news.comporium.net>,
Si Ballenger <shb*NO*SPAM*@comporium.net> wrote:

| Same here, no signal on the tx line. Bought it from
| www.compgeeks.com. Below is the type that works well.
|
| http://tinyurl.com/63tto

$1 each, $10 shipping. Bah! Why can't they just say $10 each, $1
shipping and be honest about it?
Click to expand...
Still better than $12-15 plus $8 postage from the low price
retailer

Do you know if Linux supports these?
Click to expand...
Apparently so. the below is included on the driver disk along
with windows and mac. It is by Prolific.

Release Information

Driver Version for Linux 2.4.x : V0213

Released date: 02/13/2002

Files Included in This Release:
pl2303.c
pl2303.h
usbserial.c
usb-serial.h
readme.txt
makefile

Changes in This Release:
1. To fixed using cat command problem in Linux

Anybody know of an inexpensive USB to multiple serial ports (2 or 4 I
guess) device? (Yes, I know a hub and four of these things would work
too.)
Click to expand...
Search ebay for the Edgeport 4 and 8 port serial usb adapters.
Reported to be an excellant product made by IONetworks (search
google).
 
Tim Wescott wrote:
Costas Vlachos wrote:

Not exactly a design question, but I thought some of you may be able
to help. I've just bought a USB-to-RS232 converter cable for my laptop
and it came with a weird 9-pin FEMALE to 9-pin MALE adapter. I
initially thought it was a null-modem adapter, but upon examination it
uses the following wiring which I've never seen before:

FEMALE MALE

PIN 1 o----+ +---------o PIN 1
| |
PIN 2 o--- | ---+ | PIN 2
| | |
PIN 3 o--- | -- | ---+ | PIN 3
| | | |
PIN 4 o--- | -- | -- | ---+ PIN 4
| | | |
PIN 5 o--- | -- | -- | -- | ---+ PIN 5
| | | | |
PIN 6 o----+ | +--------------o PIN 6
| | |
PIN 7 | | +----o PIN 7
| |
PIN 8 o-------- | --------+ PIN 8
|
PIN 9 +-------------------o PIN 9

CASE o-----------------------------o CASE

Note that pins 2 and 3 (TxD, RxD) are not used at all in the MALE
side! The adapter has the label "NBT/BT" on it. There is no mention
about it in the box or manual. I Googled about it but nothing relevant
came up... Any ideas on what this wiring is for?

Many thanks.

Costas


It looks like they got a connector mirrored on their board, then fixed
it with the weird connector rather than pitching the stuff and starting
over again.
Click to expand...
BT means Bluetooth and NBT is non-Bluetooth, for the burgeoning
serial-bluetooth backfit market. (I think.)
 
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