ADTRAN Express XRT, User Manual, Page: 44 / 111

Chapter 3. Installing an Analog Modem
30 Express XRT User Guide 61202.153L3-1
12.Click FINISH .
13.Click Close .
14.The external analog modem may now be used, or you may re-
start the Express Configuration Wizard and deselect the Con-
nect External Modem option to enable the Express XRT.
Configuring an External Analog Modem
If the modem does not support 230.4 kbps, dip switch 1 on the
back panel of the Express XRT must be On (down) to install and
use an external modem with the Express XRT. This limits the DTE
speed to 115.2 kbps when using the Express XRT with an external
modem. To re-enable the 230.4 kbps operation for ISDN connec-
tions, set dip switch 1 to the Off (up) position.
When using applications supporting Express XRT operation at
230.4 kbps with an external analog modem that does not support
230.4 kbps, attach the Express XRT to the high speed 16650 UART
COM port and connect the external modem to a separate COM
port. This allows the Express XRT to operate at 230.4 kbps and the
external modem to operate at the reduced speed.
Required External Analog Modem Settings
There is one setting in the external modem that is required before
trying to enable the modem with the Express Configuration Wiz-
ard. The Carrier Detect signal from the modem should be set to
Normal (track the CD signal). This can be accomplished by using
the AT command AT&C1 . AT commands can be entered into the
modem using the following procedure:
<cr> indicates to press the Enter key on the keyboard.
1. Open a terminal emulation session using HyperACCESS or
HyperTerminal.
2. Type AT_L1 <cr>
3. Type AT <cr>
4. Type ATI <cr>
5. Type AT &C1 <cr>
6. Type AT&W <cr>
7. Type AT_L0 <cr>