Strange RS232 Wiring

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
Reply to
Tim Wescott
Loading thread data ...

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: snipped-for-privacy@hot-X-mail.com SPAM-TRAPPED: Please remove "-X-" before replying

Reply to
Costas Vlachos

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
Reply to
Mark Haase

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!

formatting link

Reply to
Si Ballenger

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
Reply to
Costas Vlachos

Same here, no signal on the tx line. Bought it from

formatting link
Below is the type that works well.

formatting link

Reply to
Si Ballenger

Maybe the mystery connector fixes the bad USB->Serial adapter that has no signals on the tx/rx?

Reply to
Carl D. Smith

| Same here, no signal on the tx line. Bought it from |

formatting link
Below is the type that works well. | |
formatting link

$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.
Reply to
Doug McLaren

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: snipped-for-privacy@hot-X-mail.com SPAM-TRAPPED: Please remove "-X-" before replying

Reply to
Costas Vlachos

| Same here, no signal on the tx line. Bought it from |

formatting link
Below is the type that works well. | |
formatting link

$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.
Reply to
Doug McLaren

Still better than $12-15 plus $8 postage from the low price retailer

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

Search ebay for the Edgeport 4 and 8 port serial usb adapters. Reported to be an excellant product made by IONetworks (search google).

Reply to
Si Ballenger

Have a look at . There is a USB to dual UART 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.)

formatting link
has Linux drivers for some of the FTDI devices. Think they're OK with the newer kernels.

Cheers

Matthew

Reply to
Matthew Smith

BT means Bluetooth and NBT is non-Bluetooth, for the burgeoning serial-bluetooth backfit market. (I think.)

Reply to
Fred Bloggs

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.