Adtran express 3000 User Guide

Chapter 7.  Installing an Analog Modem

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Express 3000 User Manual

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the Express Configuration program (Tray Tool Menu) or by using a 
VT-100 terminal emulation package (such as HyperTerminal). 

If you are connecting an external analog modem that has not been 
used by a PC running Windows 95/98, you must configure it before 
you can use it (see Configuring the External Analog Modem on page 7-4).

To configure the external analog modem, set up the communications 
software so it uses the same serial COM port to which the 
Express 3000 is connected.

To install and use an external modem that does not support 
230.4 kbps, set 

 on the back panel of the Express 3000 to 

, thus limiting the DTE speed to 115.2 kbps. To re-enable the 

230.4 kbps operation for ISDN connections, set 

 to the 

 position.

When using an external analog modem that does not support 
230.4 kbps with applications that support Express 3000 operation at 
230.4 kbps, attach the Express 3000 to the high-speed 16650 UART 
COM port and connect the external analog modem to a separate COM 
port. This setup allows the Express 3000 to operate at 230.4 kbps and 
the external modem to operate at the reduced speed.

Before enabling the modem using the Express Configuration pro-
gram, set the 

 (CD) signal from the modem to 

 

(track CD signal). Use the AT command 

 to do this. To enter AT 

commands into the modem, open a VT-100 terminal emulation ses-
sion and enter the following (

 indicates you should press the 

 key to insert a carriage return):