ADTRAN 1200153L1, XRT External Analog Modem Not Detected, Difficulty with 230.4 kbps Operation

Chapter 5. Troubleshooting

External Analog Modem Not Detected

If the Express Configuration Wizard cannot detect the external analog mode verify the following:

1.The external analog modem is powered on.

2.The external analog modem is properly installed and configured for use with the Express Configuration Wizard. See Configuring an External Modem for more details on the required settings.

Difficulty with 230.4 kbps Operation

If the Express XR/XRT does not work when the DTE rate is set to 230.4 kbps inside Windows, verify the following:

1.Verify that switch 1 on the back of the Express XR/XRT is set to off (up).

2.Verify that a high speed serial card with a 16650 UART is being used and the software drivers to support the extended baud rate tables are installed.

Dial-Up Networking Difficulty

If Windows 95 Dial-Up Networking cannot talk to the Express XR/XRT, check the modem configuration for the Express XR/ XRT. Ensure the bit rate for the DTE is set correctly. If the PC is not equipped with a 16650 UART then the fastest DTE operation speed is 115.2 kbps. Ensure the speed is not higher than the PC and modem can support.

50 Express XR/XRT Quick Start Guide 61200.153L1-13