Multi-Tech Systems MT5600BA-V92 User Manual

Chapter 2 – AT Commands 

Multi-Tech Systems, Inc. AT Commands Reference Guide (S000273G) 

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A common use for these features: An automated system that needs to periodically use the 
line while giving the voice user the highest priority. The automated system makes a 
connection when the line is free. It does this without disturbing the line if the line is in use. 
The automated system periodically retries the connection until the line is free. 
Once free, it dials and makes its connection. If a voice user wishes to use the line while 
the modem is connected. the modem drops the line and gives it to the user. The modem 
will then try to regain control of the line by once again periodically retrying to establish a 
connection. 
AT-STE=7 
OK 
ATDT5551212 
CONNECT 
Sometime later, the user picks up phone 
NO CARRIER 
ATS86? 
25 
OK 
Delay 30 seconds 
ATDT5551212 
LINE-IN-USE 
Try again some time later user hangs up the phone 
CONNECT 

 

 
 

Command:  &Tn  

  

n = 0, 1, 8  

  

None 

 

 

The modem can perform selected test and diagnostic functions. A test can be run only 
when the modem is in asynchronous operation in non-error-correction mode (normal or 
direct mode). To terminate a test in progress, the escape sequence (+++) must be entered 
first.  
&T0   Abort. Stop any test in progress.  
&T1   Start local analog loopback, V.54 Loop 3. If a connection exists when this 

command is issued, the modem hangs up. A CONNECT message is displayed at 
the start of the test.  

&T8   Starts local analog loopback, V.54 Loop 3, with self-test. If a connection exists, the 

modem hangs up before the test begins. When the test is terminated, the number 
of detected errors is reported to the computer.