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Re: DB-9 Null Modem Cable



Hi John:

On a modem cable, the RS-232 RX & TX lines are wired straight through, that is
pin 2 on one end of the cable is wired to pin 2 on the other end, and pin 3 is
also wired to pin 3.

On a null-modem cable, the TX and RX pins are swapped on one end of the cable so
that RX is connected to TX, and vice versa; pin 2 on one end is connected to pin
3 on the other end, and pin 3 is connected to pin 2.

If you can not find a null-modem cable, you can open the connector on one end
and swap the wires on pins 2 & 3, or buy a null-modem adapter and add it to one
end of the cable.

73,

Woody
KJ4SO

-----Original Message-----
From: John and Darlene Johnson <kf7lf@arrl.net>
To: amsat-bb@AMSAT.Org <amsat-bb@AMSAT.Org>
Date: April 29, 1999 23:38
Subject: [amsat-bb] DB-9 Null Modem Cable


>Hi All,
>
>Been lurking for several  weeks and learning...what a great hobby!    I
>have a question concerning my FT 847...Whats the difference between a
>null modem cable and a stardard cable?  Not sure that my computer
>company sold me the right product....trying to get set up for the RATS
>FT 847 program.  Thanks for you help...greatly appreciated.   73 fer
>now.
>
>John     KF7LF
>
>
>----
>Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>


----
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