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Old 02-21-2013, 01:01 AM   #1
/dev/random
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possible to use a modem (rj-11) to talk to a serial device?


I was wondering if it were possible to talk to a serial device with a 56k modem?

As far as I can tell, both use UART, both are serial devices, so I don't see why this wouldn't work? If I got or made a RJ-11 to Serial adaptor would this actually work through minicom?


The reason why I ask is I have a notebook that still has a modem that is fully functional in linux and I also have a fully managed dell switch (powerconnect 5324) instead of buying a USB to Serial adaptor (that always never works correctly) would it be possible to interface with my switch using my 56k modem?
 
Old 02-21-2013, 05:42 AM   #2
TobiSGD
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A modem converts digital data to analog signals. RS-232 does not use analog signals, so this won't work.
 
Old 02-21-2013, 12:06 PM   #3
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Hey TobiSGD,
Thanks for giving that lil peice of information.

I have read somewhere that older external modems used a db25 cable that can interface with the AUX port on some cisco/dell hardware thats why I assumed this would be possible in the first place, The other reason why I thought this would work is because I have used two modems before with no line, just hooked up directly to each other to transfer files back in the older days. Since a modem can be set to be either listen or call (DCE or DTE) I assumed this would work.

But it makes sense if the modem itslef converts the signals to another format then it wouldnt work.

Thanks anyways
 
Old 02-21-2013, 02:55 PM   #4
jefro
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The old way was a serial port to a modem, then modem over POTS to a modem then to serial. You can still do that but you'd need to setup up a faux POTS line.

To send digital data over a phone line one converts marks and spaces (plus and minus) to audio tone packages. That is how a modem like a 56K works.
 
  


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