Multi-Tech Systems GPRS (MTMMC-G) 사용자 설명서

Chapter 11 – Data Commands  

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

97 

 

Description: 

This command enables or disables data compression negotiation if this feature is supported on the 
product.  

no compression (default) 

V42bis compression if supported 

AT%C0 
Note: Command 

OK 
Note: Feature supported 

AT%C2 
Note: Command 

OK 
Note: V42bis supported 

AT%C? 
Note: Current value  

2 
OK  
Note: Command valid 

 

 

Description:  

This command enables or disables V.42bis data compression if this feature is supported on the product. 
Note that the product allows only the MNP2 protocol. 

Values:  

< dir >   Specifies the desired direction(s) of operation of the data compression function; from the 

 

DTE point of view, (default is 3) 

0  Negotiated … no compression 
1   Transmit only 
2  Receive only 
3  Both directions, accept any direction. Default. 

< neg >  Specifies whether or not the DCE should continue to operate if the desired result is not 

obtained, (default is 0) 
0  Do not disconnect if V.42 bis is not negotiated by the remote DCE as specified in <dir>. 

Default. 

 Disconnect if V.42 bis is not negotiated by the remote DCE as specified in <dir> 

 P1 >   Specifies the maximum number of dictionary entries that should be negotiated,  

Range is 512 to 2048. Default is 2048. 

< P2 >   Specifies the maximum string length to be negotiated. Range is 6 to 250. Default is 20. 

AT+DS=[[<dir>][,[<neg>][,[<P1>][,[<P2>]]]]

AT+DS=? 
Note: Test command 

+DS: (0-3),(0,1),(512-2048),(6-250) 
OK 

AT+DS=3,0,2048,250 
Note: Set new parameters 

OK 
Note: Command valid 

AT+DS? 
Note: Current values 

+DS: 3,0,2048,20 
OK 
Note: Command valid