Subj : USR 5686 no reply at AT command
To   : rmurray
From : Digital Man
Date : Wed Aug 21 2024 08:44 pm

  Re: USR 5686 no reply at AT command
  By: rmurray to All on Wed Aug 21 2024 11:02 pm

 > I suspect there's something I'm missing or haven't done correctly. These are
 > US Robotics 5686 modems, which are standard serial modems. I've tested them
 > on several serial ports across multiple computers, including the built-in
 > ports on the motherboard and special RS232 serial cards.
 >
 > Does anyone know how to resolve this issue?

Check the DIP switches on the modem. I seem to recall one of them (or some combination) disables AT command support.

Or it could be your serial cable or serial port at fault.
-- 
                                            digital man (rob)

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