D-Link DMI-128ESU User Manual

D-LINK ISDN TA DMI-128ESU+ 

11 

1. DTE DB9-SUB male connector RS232 and USB 

 Connect to PC or DTE equipment.  
Use only one connection port (USB / Serial) at a time to connect to PC. 

2. Analog Port TEL-A, TEL-B  

Connect to the regular telephone, answering machine or fax machine. 

3. AC Power plug 

Connect to DC 5V adapter 

4. ST  

ST interface connection. You can connect to ST interface of NT1 (of ISDN Line), or connect 

other ISDN TA phone with S/T interface to make a multi-drop bus connection. 

5. FG (Frame Ground) 

Optional and not connected in this model 

In case of sudden loss of local power, the TA has a battery power backup solution. A total of 6 AA 
batteries are required to backup the TA. Please make sure all 6 batteries are placed correctly, in 
the correct polarity. (Use Alkaline Batteries for proper operation) 
 
Battery Mode Operation 
In case of sudden loss of local power, the TA will switch to battery backup mode automatically. (If 
all 6 batteries had been installed properly.)  Under the battery backup mode, all 3 data and analog 
ports can be operated normally.  
 
In battery backup mode, with average brand new batteries, the TA can last at least 6 hours in 
standby or it can run one analog port continuously for about 1 hours.

 

    

 
Changing Batteries 
Please inspect batteries if the TA does not work properly under battery backup mode. If the battery 
is low, please replace batteries. We suggest the user to replace all 6 batteries together.