COURIER HIGH SPEED MODEMS
APPENDIX E. TROUBLESHOOTING
You may occasionally encounter one of the problems listed here. They are divided into three categories: Running the SDL.EXE Upgrade Program, Before Establishing the Link, and During Data Transfer.
Running the SDL.EXE Upgrade Program
Your modem . . .
Is indicating an error
Try running the SDL program at a lower serial port rate. If your computer doesn’t have a 16550 UART, a slower serial port rate can make all the difference.
You can also try running the program on a different PC. An idiosyncracy of an
Before Establishing the Link
Your modem . . .
Doesn't answer the phone or go off hook to dial a number
Review your communications software manual to see what Data Terminal Ready (DTR) 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 DTR signal via the
Doesn'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.
Troubleshooting
