To help you make sense of things, I'll try an analogy w/o
the RX/TX tech trivia.
For two RS232 devices to talk to each other, one must
be configured as DTE and the other must be configured
as DCE. For now, don't bother with what the initials mean
... just consider them as similar to magnetic polarity i.e.
"north" and "south". North sticks to south, but north repels
north and south repels south.
So, if your computer talks to your Palm through a given
cable, one device is "north" and the other is "south". If
your computer talks to a third device through a cable X,
again one is "north" and the other is "south". Now assume
your computer is "north", that makes both the palm and
the other device "south". So if you use cable X to try
to connect the palm and the third device you've got
south-to-south and they repel.
You either need a different cable, or you need a little
device called a "null modem adapter" which performs
the nifty little trick of converting north polarity to south
(not possible using real magnets, but it was just an
analogy ;-)
--
-Richard M. Hartman
[EMAIL PROTECTED]
186,000 mi/sec: not just a good idea, it's the LAW!
Andrew Lathrop wrote in message <20387@palm-dev-forum>...
>
>Ok. Trying to make sense of what everyone said. I went to a few websites
>and tried to figure this out. From
>http://www.massena.com/darrin/pilot/luiz/item4.htm, i found out about the
>cradles connections. It said that (Arrows show direction of data, numbers
>are pins, RX - receiving, TX - trasmitting )
>6 TX ----> 2 RX ------> 2 RX
>8 RX<---- 3 TX <------ 3 TX
>Cradle Cable End Serial Port
>And i am guessing the third part, that the 2 RX connects to the 2 RX on my
>comps serial port, and the 3 TX to the 3 TX.
>From http://www.loop-back.com/null-mod.html, i figure out how the null
modem
>cable i used in the direct serial connection works.
>2 RX <------- 2 RX <-------- 3 TX <--------- 2 TX
>3 TX -------> 3 TX --------> 2 RX --------> 3 RX
>Serial Port Cable End 1 Cable End 2 SerialPort
>Device 1
>Device 2
>The more I look at this, the more confused I get. But, assuiming my
>diagrams are correct, and that i follow my own train of thought, in both
>cases the data is switched from RX to TX once. So then in theory, there
>should be no problem??? If anyone can please explain what i said, or
>correct me in any way, please let me know. Thanks for the earlier
>suggestions.
>Andrew
>Andrew Lathrop <[EMAIL PROTECTED]> wrote in message
>news:20279@palm-dev-forum...
>>
>> A question. I have written an app that works fine in the emulator. It
>uses
>> the serial port to connect to a third device via a direct serial cable.
>> When the HotSync the program to my Palm, and then try to use it on the
>Palm,
>> connecting to the third device using the HotSync cradle. It no longer
>> works. From what I can tell, the cradle isn't sending out the same stuff
>> over the serial cable. Would this be different if i got a third party
>> serial cable that had no cradle? Which would mean the HotSync cradle
>steals
>> the serial port only for its own use. Or does the actual Palm Device
>handle
>> serial communications differently? Other apps did work using the cradle,
>> but those went back to the serial port on my desktop and i talked to
>> HyperTerminal. Any ideas? Any input would be greatly appreciated,
>> Thanks
>> Andrew
>>
>>
>>
>>
>
>
>
>
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