Specifications
SIM900 AT Command Manual       
SIM900_AT Command Manual_V1.03  7  12/24/2010 
4.2.6 AT+CMGW Write SMS Message to Memory ..........................................................106 
4.2.7 AT+CMSS Send SMS Message from Storage ..........................................................108 
4.2.8 AT+CNMI New SMS Message Indications ..............................................................108 
4.2.9 AT+CPMS Preferred SMS Message Storage ............................................................ 111 
4.2.10 AT+CRES Restore SMS Settings............................................................................ 111 
4.2.11 AT+CSAS Save SMS Settings ................................................................................ 112 
4.2.12 AT+CSCA SMS Service Center Address ................................................................ 113 
4.2.13 AT+CSCB Select Cell Broadcast SMS Messages................................................... 114 
4.2.14 AT+CSDH Show SMS Text Mode Parameters ....................................................... 115 
4.2.15 AT+CSMP   Set SMS Text Mode Parameters ...........................................................115 
4.2.16 AT+CSMS Select Message Service......................................................................... 116 
5 AT Commands for SIM Application Toolkit.............................................................................118 
5.1 STK AT Command.............................................................................................................. 118 
6 AT Commands Special for SIMCOM........................................................................................120 
6.1 Overview.............................................................................................................................120 
6.2 Detailed Descriptions of Commands...................................................................................121 
6.2.1 AT+SIDET Change the Side Tone Gain Level.......................................................121 
6.2.2 AT+CPOWD Power Off ...........................................................................................122 
6.2.3 AT+SPIC Times Remained to Input SIM PIN/PUK.................................................122 
6.2.4 AT+CMIC Change the Microphone Gain Level.......................................................123 
6.2.5 AT+CALA Set Alarm Time......................................................................................124 
6.2.6 AT+CALD Delete Alarm..........................................................................................125 
6.2.7 AT+CADC Read ADC .............................................................................................125 
6.2.8 AT+CSNS Single Numbering Scheme .....................................................................125 
6.2.9 AT+CDSCB Reset Cell Broadcast............................................................................126 
6.2.10 AT+CMOD Configure Alternating Mode Calls .....................................................126 
6.2.11 AT+CFGRI Indicate RI When Using URC ............................................................127 
6.2.12 AT+CLTS Get Local Timestamp............................................................................127 
6.2.13 AT+CEXTHS External Headset Jack Control ........................................................129 
6.2.14 AT+CEXTBUT Headset Button Status Reporting .................................................130 
6.2.15 AT+CSMINS SIM Inserted Status Reporting.........................................................131 
6.2.16 AT+CLDTMF Local DTMF Tone Generation .......................................................131 
6.2.17 AT+CDRIND CS Voice/Data Call Termination Indication ...................................132 
6.2.18 AT+CSPN Get Service Provider Name from SIM ..................................................133 
6.2.19 AT+CCVM Get and Set the Voice Mail Number on the SIM .................................133 
6.2.20 AT+CBAND Get and Set Mobile Operation Band .................................................134 
6.2.21 AT+CHF Configure Hands Free Operation.............................................................135 
6.2.22 AT+CHFA Swap the Audio Channels .....................................................................135 
6.2.23 AT+CSCLK Configure Slow Clock ........................................................................136 
6.2.24 AT+CENG Switch On or Off Engineering Mode ...................................................137 
6.2.25 AT+SCLASS0 Store Class 0 SMS to SIM When Received Class 0 SMS ..............139 
6.2.26 AT+CCID Show ICCID ..........................................................................................139 
6.2.27 AT+CMTE Set Critical Temperature Operating Mode or Query Temperature......139 
6.2.28 AT+CBTE    Battery Temperature Query...................................................................140 










