US Robotics COURIER - APPENDIX D. PROBLEMS AND SOLUTIONS; Troubleshooting Before Data Link

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COURIER HIGH SPEED MODEMS
APPENDIX
D. PROBLEMS AND SOLUTIONS
You may occasionally encounter one of the problems listed here.
They are divided into two categories: before and during the
exchange of user information over the data link.
Before
Establishment of the Data Link
Your modem ...
Doesdt answer the phone or go off hook to dial a number
Review the Settings Supplement that came with the modem or
your communications software manual to see what Data
Terminal Ready (DIR) operations your software requires. Then
check to see if DIP switch 1 is set correctly. Also, check to make
sure your terminal or computer is sending a DIR signal via the
RS-232 interface.
Doesn
1
t respond OK when you type AT <Enter>
1. Make sure you're typing in either upper case or lower case
letters,
not a combination, and that you press the Enter key.
2. If you're using a computer, make sure it is in Terminal
Mode. This is a communications software function. See
Testing the Modem in Chapter 2.
3. Check to see that your terminal or software is set to the
correct bit rate and word length (7 bits with or without a
parity bit, or 8 bits and no parity). If you're using a
computer, make sure your software is set to the correct
communications port.
4. Check that DIP switch 8 is ON, for command set recognition.
If the switch is OFF, power off the modem, set the switch
ON, and power on the modem again. Try typing AT
<Enter> again.
5. Check that DIP switch 3 is ON, for result code display, and
that DIP switch 2 is OFF, for verbal result codes. If not,
change the switch(es) and type ATZ <Enter>. Or type
whichever of these commands is needed:
Problems and Solutions D-1