more serial port troubles

[Kam Leo]

On Fri, Jun 24, 2011 at 7:05 PM, Sam Varshavchik <mrsam at courier-mta.com> wrote:
> Mike Wright writes:
>
>> Sunday I'll go buy two connectors and wire my own 3-wire null modem
>> cable: ground, tx, rx.
>
> With that, you have to turn hardware flow control off.
>
> I would also recomment crossing DTR with DSR and CTS, to get hardware flow
> control.
>
>>                       I'm tending to agree with you that something in
>> the cable chain is messed up.
>
> A gender-changer is NOT the same thing as a null-modem adapter. That's the
> most common oversight. If you have something in there that swaps the genders
> around, it might be just a straight-through gender-changer. In addition to
> changing genders, the right pins need to be crossed, that's what a
> null-modem adapter does.
>

If you need the wiring diagram for a null modem do a web search.
Here's one for DB-9 connectors:
http://image.pinout.net/pinout_9_pin_files/connector_pinout.php?image=Null-Modem-cable-pin-out.png&pinout=%20Null%20Modem%20cable%20pinout%20-%20rs232%20db-9