Multi-Tech Systems GPRS (MTMMC-G) User Manual

Chapter 12 – V.24 and V.25 Commands  

Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I) 

104 

 

Description:  

This command runs various auto-tests. 

Values:  

0 

Perform software auto-tests 

 

The response will be OK if no software problem is detected (EEPROM, RAM, and ROM 
checksums); otherwise, a simple ERROR response is sent. 

1 

Perform the audio loop test (close) 

 

This is used to validate the audio loop (microphone to speaker) 

Stop the audio loop test (open) 

 

This is used to validate the audio loop (microphone to speaker) 

Command syntax: AT&T<n> 

AT&T0 
Note: Perform software auto-tests  

OK 
Note: No software problem detected, all checksums are 
correct  

AT&T1 
Note: Do the audio loop test (close)  

OK 
Note: Command valid  

AT&T2 
Note: Stop the audio loop test (open) 

OK 
Note: Command valid  

 
 

Description: 

This command is used to determine whether or not the modem echoes characters received by an 
external application (DTE). 

0 

Characters are not echoed 

1 

Characters are echoed 

Command syntax: ATE<n> 

ATE0 
Note: Characters are not echoed  

OK 
Note: Done  

ATE1 
Note: Characters are echoed  

OK 
Note: Done  

 
 

Description:  

This command is used to restore the factory settings from EEPROM. 

It only restores the parameters that can be found in the Parameters Storage table with column AT&F 
checked. Those parameters are restored in RAM and in E2P, overwriting the profile set with AT&W.  

0 

Restore factory settings 

Note: No other value is supported. 

syntax: AT&F<n> 

AT&F 
Note: Ask for restoring the factory settings 

OK 
Note: Done  

AT&F0 
Note: Ask for restoring the factory settings 

OK 
Note: Done