Name: SIM900 AT Command Manual V1.03

SIM900_AT_Command_Manual_V1.03

SIM900_AT_Command_Manual_V1.03

SIM900%20AT%20Command%20Manual

SIM900_AT%20Command%20Manual_V1.03

SIM900_AT%20Command%20Manual_V1.03

User Manual: Pdf

Open the PDF directly: View PDF PDF.
Page Count: 229 [warning: Documents this large are best viewed by clicking the View PDF Link!]

SIM900_AT Command
Manual_ V1.03
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 2 12/24/2010
Document Title: SIM900 AT Command Manual
Version: 1.03
Date: 2010-12-24
Status: Release
Document Control ID: SIM900_AT Command Manual_V1.03
General Notes
SIMCom offers this information as a service to its customers, to support application and
engineering efforts that use the products designed by SIMCom. The information provided is based
upon requirements specifically provided to SIMCom by the customers. SIMCom has not
undertaken any independent search for additional relevant information, including any information
that may be in the customer’s possession. Furthermore, system validation of this product designed
by SIMCom within a larger electronic system remains the responsibility of the customer or the
customer’s system integrator. All specifications supplied herein are subject to change.
Copyright
This document contains proprietary technical information which is the property of Shanghai
SIMCom Wireless Solutions Ltd, copying of this document and giving it to others and the using or
communication of the contents thereof, are forbidden without express authority. Offenders are
liable to the payment of damages. All rights reserved in the event of grant of a patent or the
registration of a utility model or design. All specification supplied herein are subject to change
without notice at any time.
Copyright © Shanghai SIMCom Wireless Solutions Ltd. 2010
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 3 12/24/2010
Version History
Version Chapter What is new
V1.00 New version Created on the basis of SIM900 AT Test Result
V1.01 3.2.50 AT+CALS
6.2.27 AT+CBTE
6.2.30 AT+STTONE
8.2.21 AT+CIPDPDP
8.2.25AT+CIPUDPMODE
6.2.45 AT+SGPIO
6.2.46 AT+SPWM
6.2.47 AT+ECHO
Add new command
Add new command
Add new command
Add new command
Add new command
Add new command
Add new command
Add new command
V1.02 3.2.16 AT+CLCC
3.2.30 AT+CR
Add write command
Add parameter GPRS
V1.03 6.2.47 AT+SPWM
6.2.48 AT+ECHO
6.2.50 AT+GSMBUSY
8.2.26 AT+CIPRXGET
8.2.27 AT+CIPQRCLOSE
8.2.28 AT+CIPSCONT
9.2.1 AT+SAPBR
10.2.x HTTP commands
11.2.x FTP commands
Modified the command
Modified the parameter scope
Add new command
Add new command
Add new command
Add new command
Add new command
Add new commands
Add new commands
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 4 12/24/2010
Contents
1 Introduction..................................................................................................................................11
1.1 Scope of the document.......................................................................................................... 11
1.2 Related documents ................................................................................................................ 11
1.3 Conventions and abbreviations .............................................................................................12
1.4 AT Command syntax .............................................................................................................12
1.4.1 Basic syntax ...................................................................................................................12
1.4.2 S Parameter syntax.........................................................................................................13
1.4.3 Extended Syntax.............................................................................................................13
1.4.4 Combining AT commands on the same Command line.................................................13
1.4.5 Entering successive AT commands on separate lines.....................................................13
1.5 Supported character sets........................................................................................................13
1.6 Flow control ..........................................................................................................................14
1.6.1 Software flow control (XON/XOFF flow control).........................................................14
1.6.2 Hardware flow control (RTS/CTS flow control)............................................................15
2 AT Commands According to V.25TER.......................................................................................16
2.1 Overview of AT Commands According to V.25TER ............................................................16
2.2 Detailed Description of AT Commands According to V.25TER ...........................................17
2.2.1 A/ Re-issues the Last Command Given.......................................................................17
2.2.2 ATA ANSWER AN INCOMING CALL ....................................................................17
2.2.3 ATD Mobile Originated Call to Dial A Number..........................................................18
2.2.4 ATD><n> Originate Call to Phone Number in Current Memory................................20
2.2.5 ATD><str> Originate Call to Phone Number in Memory Which Corresponds to Field
<str> ........................................................................................................................................21
2.2.6 ATDL Redial Last Telephone Number Used...............................................................23
2.2.7 ATE Set Command Echo Mode ..................................................................................23
2.2.8 ATH Disconnect Existing Connection.........................................................................24
2.2.9 ATI Display Product Identification Information .........................................................25
2.2.10 ATL Set Monitor speaker loudness............................................................................25
2.2.11 ATM Set Monitor Speaker Mode ..............................................................................25
2.2.12 +++ Switch from Data Mode or PPP Online Mode to Command Mode ..................25
2.2.13 ATO Switch from Command Mode to Data Mode....................................................26
2.2.14 ATP Select Pulse Dialling..........................................................................................26
2.2.15 ATQ Set Result Code Presentation Mode..................................................................26
2.2.16 ATS0 Set Number of Rings before Automatically Answering the Call.....................27
2.2.17 ATS3 Set Command Line Termination Character .....................................................27
2.2.18 ATS4 Set Response Formatting Character ................................................................28
2.2.19 ATS5 Set Command Line Editing Character.............................................................28
2.2.20 ATS6 Pause Before Blind Dialling............................................................................29
2.2.21 ATS7 Set Number of Seconds to Wait for Connection Completion..........................29
2.2.22 ATS8 Set Number of Seconds to Wait for Comma Dial Modifier Encountered in Dial
String of D Command .............................................................................................................30
2.2.23 ATS10 Set Disconnect Delay after Indicating the Absence of Data Carrier..............30
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 5 12/24/2010
2.2.24 ATT Select Tone Dialing ...........................................................................................31
2.2.25 ATV TA Response Format .......................................................................................31
2.2.26 ATX Set CONNECT Result Code Format and Monitor Call Progress .....................32
2.2.27 ATZ Reset Default Configuration .............................................................................32
2.2.28 AT&C Set DCD Function Mode ...............................................................................33
2.2.29 AT&D Set DTR Function Mode................................................................................34
2.2.30 AT&F Factory Defined Configuration ......................................................................34
2.2.31 AT&V Display Current Configuration ......................................................................36
2.2.32 AT&W Store Active Profile ......................................................................................36
2.2.33 AT+GCAP Request Complete TA Capabilities List ..................................................37
2.2.34 AT+GMI Request Manufacturer Identification .........................................................37
2.2.35 AT+GMM Request TA Model Identification ............................................................38
2.2.36 AT+GMR Request TA Revision Identification of Software Release.........................38
2.2.37 AT+GOI Request Global Object Identification.........................................................38
2.2.38 AT+GSN Request TA Serial Number Identification (IMEI) .....................................39
2.2.39 AT+ICF Set TE-TA Control Character Framing........................................................39
2.2.40 AT+IFC Set TE-TA Local Data Flow Control ..........................................................40
2.2.41 AT+IPR Set TE-TA Fixed Local Rate .......................................................................41
2.2.42 AT+HVOIC Disconnect Voice Call Only..................................................................42
3 AT Commands According to GSM07.07.....................................................................................43
3.1 Overview of AT Command According to GSM07.07 ...........................................................43
3.2 Detailed Descriptions of AT Command According to GSM07.07 ........................................44
3.2.1 AT+CACM Accumulated Call Meter (ACM) Reset or Query....................................44
3.2.2 AT+CAMM Accumulated Call Meter Maximum (ACM max) Set or Query .............45
3.2.3 AT+CAOC Advice of Charge .....................................................................................46
3.2.4 AT+CBST Select Bearer Service Type........................................................................47
3.2.5 AT+CCFC Call Forwarding Number and Conditions Control ....................................48
3.2.6 AT+CCWA Call Waiting Control ................................................................................49
3.2.7AT+CEER Extended Error Report ...............................................................................51
3.2.8 AT+CGMI Request Manufacturer Identification ........................................................53
3.2.9 AT+CGMM Request Model Identification..................................................................53
3.2.10 AT+CGMR Request TA Revision Identification of Software Release ......................54
3.2.11 AT+CGSN Request Product Serial Number Identification (Identical with +GSN)...54
3.2.12 AT+CSCS Select TE Character Set...........................................................................55
3.2.13 AT+CSTA Select Type of Address ............................................................................56
3.2.14 AT+CHLD Call Hold and Multiparty........................................................................56
3.2.15 AT+CIMI Request International Mobile Subscriber Identity....................................57
3.2.16 AT+CLCC List Current Calls of ME.........................................................................58
3.2.17 AT+CLCK Facility Lock...........................................................................................60
3.2.18 AT+CLIP Calling Line Identification Presentation ...................................................61
3.2.19 AT+CLIR Calling Line Identification Restriction.....................................................62
3.2.20 AT+CMEE Report Mobile Equipment Error.............................................................63
3.2.21 AT+COLP Connected Line Identification Presentation ............................................64
3.2.22 AT+COPS Operator Selection...................................................................................66
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 6 12/24/2010
3.2.23 AT+CPAS Phone Activity Status...............................................................................67
3.2.24 AT+CPBF Find Phonebook Entries...........................................................................67
3.2.25 AT+CPBR Read Current Phonebook Entries ............................................................69
3.2.26 AT+CPBS Select Phonebook Memory Storage.........................................................69
3.2.27 AT+CPBW Write Phonebook Entry..........................................................................71
3.2.28 AT+CPIN Enter PIN..................................................................................................72
3.2.29 AT+CPWD Change Password...................................................................................73
3.2.30 AT+CR Service Reporting Control ...........................................................................74
3.2.31 AT+CRC Set Cellular Result Codes for Incoming Call Indication ...........................74
3.2.32 AT+CREG Network Registration..............................................................................75
3.2.33 AT+CRLP Select Radio Link Protocol Parameters ...................................................77
3.2.34 AT+CRSM Restricted SIM Access ...........................................................................77
3.2.35 AT+CSQ Signal Quality Report ................................................................................78
3.2.36 AT+FCLASS FAX: Select, Read or Test Service Class ............................................79
3.2.37 AT+FMI FAX: Report Manufactured ID...................................................................80
3.2.38 AT+FMM FAX: Report Model ID ............................................................................80
3.2.39 AT+FMR FAX: Report Revision ID .........................................................................80
3.2.40 AT+VTD Tone Duration............................................................................................81
3.2.41 AT+VTS DTMF and Tone Generation......................................................................81
3.2.42 AT+CMUX Multiplexer Control...............................................................................82
3.2.43 AT+CNUM Subscriber Number................................................................................84
3.2.44 AT+CPOL Preferred Operator List............................................................................85
3.2.45 AT+COPN Read Operator Names.............................................................................85
3.2.46 AT+CFUN Set Phone Functionality ..........................................................................86
3.2.47 AT+CCLK Clock.......................................................................................................87
3.2.48 AT+CSIM Generic SIM Access ................................................................................87
3.2.49 AT+CALM Alert Sound Mode..................................................................................88
3.2.50 AT+CALS Alert Sound Select...................................................................................89
3.2.51 AT+CRSL Ringer Sound Level.................................................................................89
3.2.52 AT+CLVL Loud Speaker Volume Level ...................................................................90
3.2.53 AT+CMUT Mute Control..........................................................................................91
3.2.54 AT+CPUC Price Per Unit and Currency Table..........................................................92
3.2.55 AT+CCWE Call Meter Maximum Event ..................................................................92
3.2.56 AT+CBC Battery Charge...........................................................................................93
3.2.57 AT+CUSD Unstructured Supplementary Service Data.............................................94
3.2.58 AT+CSSN Supplementary Services Notification ......................................................95
4 AT Commands According to GSM07.05.....................................................................................97
4.1 Overview of AT Commands According to GSM07.05..........................................................97
4.2 Detailed Descriptions of AT Commands According to GSM07.05.......................................97
4.2.1 AT+CMGD Delete SMS Message...............................................................................97
4.2.2 AT+CMGF Select SMS Message Format ...................................................................98
4.2.3 AT+CMGL List SMS Messages from Preferred Store................................................99
4.2.4 AT+CMGR Read SMS Message...............................................................................102
4.2.5 AT+CMGS Send SMS Message................................................................................105
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
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 8 12/24/2010
6.2.29 AT+CSDT Switch On or Off Detecting SIM Card.................................................140
6.2.30 AT+CMGDA Delete All SMS................................................................................141
6.2.31 AT+STTONE Play SIM Toolkit Tone....................................................................142
6.2.32 AT+SIMTONE Generate Specifically Tone...........................................................143
6.2.33 AT+CCPD Enable or Disable Alpha String............................................................143
6.2.34 AT+CGID Get SIM Card Group Identifier.............................................................144
6.2.35 AT+MORING Show State of Mobile Originated Call............................................144
6.2.36 AT+CMGHEX Enable or Disable Sending Non-ASCII Character SMS ...............145
6.2.37AT+AUTEST Audio Channel Loopback Test.........................................................146
6.2.38AT+CCODE Configure SMS Code Mode...............................................................146
6.2.39 AT+CIURC Enable or Disable Initial URC Presentation .......................................147
6.2.40 AT+CPSPWD Change PS Super Password ............................................................147
6.2.41 AT+EXUNSOL Enable or Disable Proprietary Unsolicited Indications.................148
6.2.42 AT+CGMSCLASS Change GPRS Multislot Class ................................................148
6.2.43 AT+CDEVICE View Current Flash Device Type ..................................................149
6.2.44 AT+CCALR Call Ready Query ..............................................................................149
6.2.45 AT+GSV Display Product Identification Information.............................................150
6.2.46 AT+SGPIO Control the GPIO .................................................................................150
6.2.47 AT+SPWM Generate the Pulse-Width-Modulation ................................................151
6.2.48 AT+ECHO Echo Cancellation Control ...................................................................152
6.2.49 AT+CAAS Control Auto Audio Switch ..................................................................153
6.2.50 AT+SVR Configure Voice Coding Type for Voice Calls.........................................154
6.2.51 AT+GSMBUSY Reject Incoming Call....................................................................155
7 AT Commands for GPRS Support.............................................................................................156
7.1 Overview of AT Commands for GPRS Support..................................................................156
7.2 Detailed Descriptions of AT Commands for GPRS Support...............................................156
7.2.1 AT+CGATT Attach or Detach from GPRS Service ..................................................156
7.2.2 AT+CGDCONT Define PDP Context .......................................................................157
7.2.3 AT+CGQMIN Quality of Service Profile (Minimum Acceptable) ...........................159
7.2.4 AT+CGQREQ Quality of Service Profile (Requested) .............................................160
7.2.5 AT+CGACT PDP Context Activate or Deactivate....................................................162
7.2.6 AT+CGDATA Enter Data State .................................................................................162
7.2.7 AT+CGPADDR Show PDP Address .........................................................................163
7.2.8 AT+CGCLASS GPRS Mobile Station Class.............................................................164
7.2.9 AT+CGEREP Control Unsolicited GPRS Event Reporting......................................165
7.2.10 AT+CGREG Network Registration Status ..............................................................166
7.2.11 AT+CGSMS Select Service for MO SMS Messages ..............................................167
8 AT Commands for TCPIP Application Toolkit .........................................................................169
8.1 Overview.............................................................................................................................169
8.2 Detailed Descriptions of Commands...................................................................................170
8.2.1 AT+CIPMUX Start Up Multi-IP Connection ............................................................170
8.2.2 AT+CIPSTART Start Up TCP or UDP Connection...................................................170
8.2.3 AT+CIPSEND Send Data Through TCP or UDP Connection...................................172
8.2.4 AT+CIPQSEND Select Data Transmitting Mode .....................................................174
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 9 12/24/2010
8.2.5 AT+CIPACK Query Previous Connection Data Transmitting State..........................175
8.2.6 AT+CIPCLOSE Close TCP or UDP Connection .....................................................176
8.2.7 AT+CIPSHUT Deactivate GPRS PDP Context ........................................................176
8.2.8 AT+CLPORT Set Local Port.....................................................................................177
8.2.9 AT+CSTT Start Task and Set APN, USER NAME, PASSWORD...........................177
8.2.10 AT+CIICR Bring Up Wireless Connection with GPRS or CSD .............................178
8.2.11 AT+CIFSR Get Local IP Address............................................................................179
8.2.12 AT+CIPSTATUS Query Current Connection Status ...............................................179
8.2.13 AT+CDNSCFG Configure Domain Name Server...................................................181
8.2.14 AT+CDNSGIP Query the IP Address of Given Domain Name...............................181
8.2.15 AT+CIPHEAD Add an IP Head at the Beginning of a Package Received..............182
8.2.16 AT+CIPATS Set Auto Sending Timer .....................................................................183
8.2.17 AT+CIPSPRT Set Prompt of ‘>’ When Module Sends Data...................................183
8.2.18 AT+CIPSERVER Configure Module as Server ......................................................184
8.2.19 AT+CIPCSGP Set CSD or GPRS for Connection Mode ........................................185
8.2.20 AT+CIPSRIP Show Remote IP Address and Port When Received Data ................186
8.2.21 AT+CIPDPDP Set Whether to Check State of GPRS Network Timing ..................187
8.2.22 AT+CIPMODE Select TCPIP Application Mode....................................................188
8.2.23AT+CIPCCFG Configure Transparent Transfer Mode ............................................188
8.2.24 AT+CIPSHOWTP Display Transfer Protocol in IP Head When Received Data.....189
8.2.25 AT+CIPUDPMODE UDP Extended Mode.............................................................190
8.2.26 AT+CIPRXGET Get Data from Network Manually ...............................................191
8.2.27 AT+CIPQRCLOSE Quick Remote Close ...............................................................192
8.2.28 AT+CIPSCONT Save TCPIP Application Context .................................................192
9 AT Commands for IP Application .............................................................................................194
9.1 Overview.............................................................................................................................194
9.2 Detailed Descriptions of Commands...................................................................................194
9.2.1 AT+SAPBR Bearer Settings for Applications Based on IP.......................................194
10 AT Commands for HTTP Application.....................................................................................196
10.1 Overview...........................................................................................................................196
10.2 Detailed Descriptions of Commands.................................................................................196
10.2.1 AT+HTTPINIT Initialize HTTP Service .................................................................196
10.2.2 AT+HTTPTERM Terminate HTTP Service............................................................196
10.2.3 AT+HTTPPARA Set HTTP Parameters Value ........................................................197
10.2.4 AT+HTTPDATA Input HTTP Data .........................................................................198
10.2.5 AT+HTTPACTION HTTP Method Action .............................................................199
10.2.6 AT+HTTPREAD Read the HTTP Server Response................................................201
10.2.7 AT+HTTPSCONT Save HTTP Application Context ..............................................202
11 AT Commands for FTP Application........................................................................................203
11.1 Overview...........................................................................................................................203
11.2 Detailed Descriptions of Commands.................................................................................203
11.2.1 AT+FTPPORT Set FTP Control Port.......................................................................203
11.2.2 AT+FTPMODE Set Active or Passive FTP Mode...................................................204
11.2.3 AT+FTPTYPE Set the Type of Data to Be Transferred...........................................205
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 10 12/24/2010
11.2.4 AT+FTPPUTOPT Set FTP Put Type .......................................................................205
11.2.5 AT+FTPCID Set FTP Bearer Profile Identifier .......................................................206
11.2.6 AT+FTPREST Set Resume Broken Download .......................................................206
11.2.7 AT+FTPSERV Set FTP Server Address ..................................................................207
11.2.8 AT+FTPUN Set FTP User Name ............................................................................208
11.2.9 AT+FTPPW Set FTP Password ...............................................................................208
11.2.10 AT+FTPGETNAME Set Download File Name ....................................................209
11.2.11 AT+FTPGETPATH Set Download File Path .........................................................209
11.2.12 AT+FTPPUTNAME Set Upload File Name .........................................................210
11.2.13 AT+FTPPUTPATH Set Upload File Path.............................................................. 211
11.2.14 AT+FTPGET Download File................................................................................. 211
11.2.15 AT+FTPPUT Set Upload File................................................................................212
11.2.16 AT+FTPSCONT Save FTP Application Context ..................................................213
12 Supported Unsolicited Result Codes........................................................................................215
12.1 Summary of CME ERROR Codes....................................................................................215
12.2 Summary of CMS ERROR Codes ....................................................................................216
13 AT Commands Sample ............................................................................................................219
13.1 Profile Commands.............................................................................................................219
13.2 SIM Commands ................................................................................................................220
13.3 General Commands...........................................................................................................221
13.4 Call Control Commands....................................................................................................222
13.5 SIM Toolkit Commands....................................................................................................224
13.6 Audio Commands..............................................................................................................224
13.7 SMS Commands ...............................................................................................................224
13.8 GPRS Commands .............................................................................................................226
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 11 12/24/2010
1 Introduction
1.1 Scope of the document
This document presents the AT Command Set for SIMCOM SIM900 series cellular engine.
1.2 Related documents
You can visit the SIMCom Website using the following link:
http://www.sim.com
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 12 12/24/2010
1.3 Conventions and abbreviations
In this document, the GSM engines are referred to as following term:
1) ME (Mobile Equipment);
2) MS (Mobile Station);
3) TA (Terminal Adapter);
4) DCE (Data Communication Equipment) or facsimile DCE (FAX modem, FAX board);
In application, controlling device controls the GSM engine by sending AT Command via its serial
interface. The controlling device at the other end of the serial line is referred to as following term:
1) TE (Terminal Equipment);
2) DTE (Data Terminal Equipment) or plainly "the application" which is running on an
embedded system;
1.4 AT Command syntax
The "AT" or "at" prefix must be set at the beginning of each Command line. To terminate a
Command line enter <CR>.
Commands are usually followed by a response that includes. "<CR><LF><response><CR><LF>"
Throughout this document, only the responses are presented, <CR><LF> are omitted
intentionally.
The AT Command set implemented by SIM900 is a combination of GSM07.05, GSM07.07 and
ITU-T recommendation V.25ter and the AT commands developed by SIMCom.
Note: A HEX string such as "00 49 49 49 49 FF FF FF FF" will be sent out through serial
port at the baud rate of 115200 immediately after SIM900 is powered on. The string shall be
ignored since it is used for synchronization with PC tool. Only enter AT Command through
serial port after SIM900 is powered on and Unsolicited Result Code "RDY" is received from
serial port. If auto-bauding is enabled, the Unsolicited Result Codes "RDY" and so on are
not indicated when you start up the ME, and the "AT" prefix, not "at" prefix must be set at
the beginning of each command line.
All these AT commands can be split into three categories syntactically: "basic", "S parameter",
and "extended". These are as follows:
1.4.1 Basic syntax
These AT commands have the format of "AT<x><n>", or "AT&<x><n>", where "<x>"is the
Command, and "<n>"is/are the argument(s) for that Command. An example of this is "ATE<n>",
which tells the DCE whether received characters should be echoed back to the DTE according to
the value of "<n>". "<n>" is optional and a default will be used if missing.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 13 12/24/2010
1.4.2 S Parameter syntax
These AT commands have the format of "ATS<n>=<m>", where "<n>" is the index of the S
register to set, and "<m>"is the value to assign to it. "<m>" is optional; if it is missing, then a
default value is assigned.
1.4.3 Extended Syntax
These commands can operate in several modes, as in the following table:
Table 1: Types of AT commands and responses
Test Command AT+ <x>=? The mobile equipment returns the list of parameters
and value ranges set with the corresponding Write
Command or by internal processes.
Read Command AT+ <x>? This command returns the currently set value of the
parameter or parameters.
Write Command AT+<x>=<…> This command sets the user-definable parameter
values.
Execution Command AT+ <x > The execution command reads non-variable
parameters affected by internal processes in the GSM
engine.
1.4.4 Combining AT commands on the same Command line
You can enter several AT commands on the same line. In this case, you do not need to type the
"AT" or "at" prefix before every command. Instead, you only need type "AT" or "at" the
beginning of the command line. Please note to use a semicolon as the command delimiter after an
extended command, for example: ATE1&W&F+ICF?; +CFUN?; &W.
The Command line buffer can accept a maximum of 556 characters. If the characters entered
exceeded this number then none of the Command will executed and TA will return "ERROR".
1.4.5 Entering successive AT commands on separate lines
When you need to enter a series of AT commands on separate lines, please Note that you need to
wait the final response (for example OK, CME error, CMS error) of last AT Command you entered
before you enter the next AT Command.
1.5 Supported character sets
The SIM900 AT Command interface defaults to the IRA character set. The SIM900 supports the
following character sets:
GSM format
UCS2
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 14 12/24/2010
HEX
IRA
PCCP
PCDN
8859-1
The character set can be set and interrogated using the "AT+CSCS" Command (GSM 07.07).
The character set is defined in GSM specification 07.05.
The character set affects transmission and reception of SMS and SMS Cell Broadcast messages,
the entry and display of phone book entries text field and SIM Application Toolkit alpha strings.
1.6 Flow control
Flow control is very important for correct communication between the GSM engine and DTE. For
in the case such as a data or fax call, the sending device is transferring data faster than the
receiving side is ready to accept. When the receiving buffer reaches its capacity, the receiving
device should be capable to cause the sending device to pause until it catches up.
There are basically two approaches to achieve data flow control: software flow control and
hardware flow control. SIM900 support both two kinds of flow control.
In Multiplex mode, it is recommended to use the hardware flow control.
1.6.1 Software flow control (XON/XOFF flow control)
Software flow control sends different characters to stop (XOFF, decimal 19) and resume (XON,
decimal 17) data flow. It is quite useful in some applications that only use three wires on the serial
interface.
The default flow control approach of SIM900 is hardware flow control (RTS/CTS flow control), to
enable software flow control in the DTE interface and within GSM engine, type the following AT
Command:
AT+IFC=1, 1
This setting is stored volatile, for use after restart, AT+IFC=1, 1 should be stored to the user
profile with AT&W.
NOTE:
The AT commands listed in the table of AT&W chapter should be stored to user profile with
AT&W for use after restart. Most other AT commands in V.25, 07.05, 07.07, GPRS will store
parameters automatically and can be used after module restart.
Ensure that any communications software package (e.g. Hyper terminal) uses software flow
control.
NOTE:
Software Flow control should not be used for data calls where binary data will be transmitted or
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 15 12/24/2010
received (e.g. TCP/IP) as the DTE interface may interpret binary data as flow control characters.
1.6.2 Hardware flow control (RTS/CTS flow control)
Hardware flow control achieves the data flow control by controlling the RTS/CTS line. When the
data transfer should be suspended, the CTS line is set inactive until the transfer from the receiving
buffer has completed. When the receiving buffer is ok to receive more data, CTS goes active once
again.
To achieve hardware flow control, ensure that the RTS/CTS lines are present on your application
platform.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 16 12/24/2010
2 AT Commands According to V.25TER
These AT Commands are designed according to the ITU-T (International Telecommunication
Union, Telecommunication sector) V.25ter document.
2.1 Overview of AT Commands According to V.25TER
Command Description
A/ RE-ISSUES THE LAST COMMAND GIVEN
ATA ANSWER AN INCOMING CALL
ATD MOBILE ORIGINATED CALL TO DIAL A NUMBER
ATD><N> ORIGINATE CALL TO PHONE NUMBER IN CURRENT MEMORY
ATD><STR> ORIGINATE CALL TO PHONE NUMBER IN MEMORY WHICH
CORRESPONDS TO FIELD <STR>
ATD L REDIAL LAST TELEPHONE NUMBER USED
ATE SET COMMAND ECHO MODE
ATH DISCONNECT EXISTING CONNECTION
ATI DISPLAY PRODUCT IDENTIFICATION INFORMATION
ATL SET MONITOR SPEAKER LOUDNESS
ATM SET MONITOR SPEAKER MODE
+++ SWITCH FROM DATA MODE OR PPP ONLINE MODE TO
COMMAND MODE
ATO SWITCH FROM COMMAND MODE TO DATA MODE
ATP SELECT PULSE DIALLING
ATQ SET RESULT CODE PRESENTATION MODE
ATS 0 SET NUMBER OF RINGS BEFORE AUTOMATICALLY
ANSWERING THE CALL
ATS 3 SET COMMAND LINE TERMINATION CHARACTER
ATS 4 SET RESPONSE FORMATTING CHARACTER
ATS 5 SET COMMAND LINE EDITING CHARACTER
ATS 6 PAUSE BEFORE BLIND DIALLING
ATS 7 SET NUMBER OF SECONDS TO WAIT FOR CONNECTION
COMPLETION
ATS 8 SET NUMBER OF SECONDS TO WAIT FOR COMMA DIAL
MODIFIER ENCOUNTERED IN DIAL STRING OF D COMMAND
ATS10 SET DISCONNECT DELAY AFTER INDICATING THE ABSENCE OF
DATA CARRIER
ATT SELECT TONE DIALING
ATV TA RESPONSE FORMAT
ATX SET CONNECT RESULT CODE FORMAT AND MONITOR CALL
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 17 12/24/2010
PROGRESS
ATZ RESET DEFAULT CONFIGURATION
AT& C SET DCD FUNCTION MODE
AT& D SET DTR FUNCTION MODE
AT& F FACTORY DEFINED CONFIGURATION
AT& V DISPLAY CURRENT CONFIGURATION
AT& W STORE ACTIVE PROFILE
AT+ GC AP REQUEST COMPLETE TA CAPABILITIES LIST
AT+ GM I REQUEST MANUFACTURER IDENTIFICATION
AT+GMM REQUEST TA MODEL IDENTIFICATION
AT+ GM R REQUEST TA REVISION IDENTIFICATION OF SOFTWARE
RELEASE
AT+GOI REQUEST GLOBAL OBJECT IDENTIFICATION
AT+ GS N REQUEST TA SERIAL NUMBER IDENTIFICATION (IMEI)
AT+ IC F SET TE-TA CONTROL CHARACTER FRAMING
AT+ IF C SET TE-TA LOCAL DATA FLOW CONTROL
AT+ IP R SET TE-TA FIXED LOCAL RATE
AT+HVOIC DISCONNECT VOICE CALL ONLY
2.2 Detailed Description of AT Commands According to V.25TER
2.2.1 A/ Re-issues the Last Command Given
A/ Re-issues the Last Command Given
Execution
Command
A/
Response
Re-issues the previous Command
Reference
V.25ter
Note
2.2.2 ATA ANSWER AN INCOMING CALL
ATA ANSWER AN INCOMING CALL
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 18 12/24/2010
Execution
Command
ATA
Response
TA sends off-hook to the remote station.
Note1: Any additional commands on the same Command line are ignored.
Note2: This Command may be aborted generally by receiving a character
during execution. The aborting is not possible during some states of
connection establishment such as handshaking.
Response in case of data call, if successfully connected
CONNECT<text> TA switches to data mode.
Note: <text> output only if ATX<value> parameter setting with the
<value>>0
When TA returns to Command mode after call release
OK
Response in case of voice call, if successfully connected
OK
Response if no connection
NO CARRIER
Reference
V.25ter
Note
See also ATX
2.2.3 ATD Mobile Originated Call to Dial A Number
ATD Mobile Originated Call to Dial A Number
Execution
Command
ATD<n>[<mgsm
][;]
Response
This Command can be used to set up outgoing voice, data or fax calls. It
also serves to control supplementary services.
Note: This Command may be aborted generally by receiving an ATH
Command or a character during execution. The aborting is not possible
during some states of connection establishment such as handshaking.
If no dial tone and (parameter setting ATX2 or ATX4)
NO DIALTONE
If busy and (parameter setting ATX3 or ATX4)
BUSY
If a connection cannot be established
NO CARRIER
If the remote station does not answer
NO ANSWER
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 19 12/24/2010
If connection successful and non-voice call.
CONNECT<text> TA switches to data mode.
Note: <text> output only if ATX<value> parameter setting with the
<value> >0
When TA returns to Command mode after call release
OK
If connection successful and voice call
OK
Parameters
<n> String of dialing digits and optionally V.25ter modifiers dialing
digits:
0-9, * , #, +, A, B, C
Following V.25ter modifiers are ignored:
,(comma), T, P, !, W, @
Emergency call:
<n> Standardized emergency number 112 (no SIM needed)
<mgsm> String of GSM modifiers:
I Actives CLIR (Disables presentation of own number
to called party)
i Deactivates CLIR (Enable presentation of own number
to called party)
G Activates Closed User Group invocation for this call
only
g Deactivates Closed User Group invocation for this call
only
<;> Only required to set up voice call , return to Command state
Reference
V.25ter
Note
z Parameter "I" and "i" only if no *# code is within the dial string
z <n> is default for last number that can be dialed by ATDL
z *# codes sent with ATD are treated as voice calls. Therefore, the
Command must be terminated with a semicolon ";"
z See ATX Command for setting result code and call monitoring
parameters.
Responses returned after dialing with ATD
z For voice call two different responses mode can be determined. TA
returns "OK" immediately either after dialing was completed or after
the call is established. The setting is controlled by AT+COLP. Factory
default is AT+COLP=0, this cause the TA returns "OK" immediately
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 20 12/24/2010
after dialing was completed, otherwise TA will returns "OK",
"BUSY", "NO DIAL TONE", "NO CARRIER".
Using ATD during an active voice call:
z When a user originates a second voice call while there is already an
active voice call, the first call will be automatically put on hold.
z The current states of all calls can be easily checked at any time by
using the AT+CLCC Command.
2.2.4 ATD><n> Originate Call to Phone Number in Current Memory
ATD><n> Originate Call to Phone Number in Current Memory
Execution
Command
ATD><n>[<clir>
][ <cug>][;]
Response
This Command can be used to dial a phone number from current phonebook
memory.
Note: This Command may be aborted generally by receiving an ATH
Command or a character during execution. The aborting is not possible
during some states of connection establishment such as handshaking.
If error is related to ME functionality
+CME ERROR: <err>
If no dial tone and (parameter setting ATX2 or ATX4)
NO DIALTONE
If busy and (parameter setting ATX3 or ATX4)
BUSY
If a connection cannot be established
NO CARRIER
If the remote station does not answer
NO ANSWER
If connection successful and non-voice call.
CONNECT<text> TA switches to data mode.
Note: <text> output only if ATX<value> parameter setting with the
<value> >0
When TA returns to Command mode after call release
OK
If successfully connected and voice call
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 21 12/24/2010
OK
Parameters
<n> Integer type memory location should be in the range of
locations available in the memory used
<mgsm> String of GSM modifiers:
<clir>
I Override the CLIR supplementary service subscription
default value for this call
Invocation (restrict CLI presentation)
i Override the CLIR supplementary service subscription
default value for this call
Suppression (allow CLI presentation)
<cug>
G Control the CUG supplementary service information
for this call
CUG Not supported
g Control the CUG supplementary service information
for this call
CUG Not supported
<;> Only required to set up voice call , return to Command state
Reference
V.25ter
Note
z Parameter "I" and "i" only if no *# code is within the dial string
z *# codes sent with ATD are treated as voice calls. Therefore, the
Command must be terminated with a semicolon ";"
z See ATX Command for setting result code and call monitoring
parameters.
2.2.5 ATD><str> Originate Call to Phone Number in Memory Which Corresponds to Field
<str>
ATD><str> Originate Call to Phone Number in Memory Which Corresponds to Field
<str>
Execution
Command
ATD><str>[<clir
>][<cug>][;]
Response
This Command make the TA attempts to set up an outgoing call to stored
number.
All available memories are searched for the entry <str>.
Note: This Command may be aborted generally by receiving an ATH
Command or a character during execution. The aborting is not possible
during some states of connection establishment such as handshaking.
If error is related to ME functionality
+CME ERROR: <err>
If no dial tone and (parameter setting ATX2 or ATX4)
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 22 12/24/2010
NO DIALTONE
If busy and (parameter setting ATX3 or ATX4)
BUSY
If a connection cannot be established
NO CARRIER
If the remote station does not answer
NO ANSWER
If connection successful and non-voice call.
CONNECT<text> TA switches to data mode.
Note: <text> output only if ATX<value> parameter setting with the
<value> >0
When TA returns to Command mode after call release
OK
If successfully connected and voice call
OK
Parameters
<str> String type (string should be included in quotation marks)
value ("x"), which should equal to an alphanumeric field in
at least one phone book entry in the searched memories. str
formatted as current TE character set specified by +CSCS.
<mgsm> String of GSM modifiers:
I Actives CLIR (Disables presentation of own number
to called party)
i Deactivates CLIR (Enable presentation of own number
to called party)
G Activates Closed User Group invocation for this call
only
g Deactivates Closed User Group invocation for this call
only
<;> only required to set up voice call , return to Command state
Reference
V.25ter
Note
z Parameter "I" and "i" only if no *# code is within the dial string
z *# codes sent with ATD are treated as voice calls. Therefore, the
Command must be terminated with a semicolon ";"
z See ATX Command for setting result code and call monitoring
parameters.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 23 12/24/2010
2.2.6 ATDL Redial Last Telephone Number Used
ATDL Redial Last Telephone Number Used
Execution
Command
ATDL
Response
This Command redials the last voice and data call number used.
Note: This Command may be aborted generally by receiving an ATH
Command or a character during execution. The aborting is not possible
during some states of connection establishment such as handshaking.
If error is related to ME functionality
+CME ERROR: <err>
If no dial tone and (parameter setting ATX2 or ATX4)
NO DIALTONE
If busy and (parameter setting ATX3 or ATX4)
BUSY
If a connection cannot be established
NO CARRIER
If the remote station does not answer
NO ANSWER
If connection successful and non-voice call.
CONNECT<text> TA switches to data mode.
Note: <text> output only if ATX<value> parameter setting with the
<value> >0
When TA returns to Command mode after call release
OK
If successfully connected and voice call
OK
Reference
V.25ter
Note
z See ATX Command for setting result code and call monitoring
parameters.
z Return the numbers and symbols which ATD supports if there is no
last dialing context.
2.2.7 ATE Set Command Echo Mode
ATE Set Command Echo Mode
Execution Response
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 24 12/24/2010
This setting determines whether or not the TA echoes characters received
from TE during Command state.
OK
Command
ATE<value>
Parameter
<value> 0 Echo mode off
1 Echo mode on
Reference
V.25ter
Note
2.2.8 ATH Disconnect Existing Connection
ATH Disconnect Existing Connection
Response
Disconnect existing call by local TE from Command line and terminate call
OK
Note: OK is issued after circuit 109(DCD) is turned off, if it was previously
on.
Execution
Command
ATH[n]
Parameter
<n> 0 Disconnect ALL calls on the channel the command is
requested. All active or waiting calls, CS data calls, GPRS call
of the channel will be disconnected.
1 Disconnect all calls on ALL connected channels. All active or
waiting calls, CSD calls, GPRS call will be disconnected.
(clean up of all calls of the ME)
2 Disconnect all connected CS data call only on the channel
the command is requested. (speech calls (active or waiting)
or GPRS calls are not disconnected)
3 Disconnect all connected GPRS calls only on the channel
the command is requested (speech calls (active or waiting)
or CS data calls are not disconnected.
4 Disconnect all CS calls (either speech or data) but does not
disconnect waiting call (either speech or data) on the
channel the command is requested.
5 Disconnect waiting call (either speech or data) but does not
disconnect other active calls (either CS speech, CS data or
GPRS) on the channel the command is requested.
(rejection of incoming call)
Reference
V.25ter
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 25 12/24/2010
2.2.9 ATI Display Product Identification Information
ATI Display Product Identification Information
Execution
Command
ATI
Response
TA issues product information text
Example:
SIM900 R11.0
OK
Reference
V.25ter
Note
2.2.10 ATL Set Monitor speaker loudness
ATL Set Monitor speaker loudness
Response
OK
Execution
Command
ATL<value> Parameter
<value> 0..9 volume
Reference
V.25ter
Note
No effect in GSM
2.2.11 ATM Set Monitor Speaker Mode
ATM Set Monitor Speaker Mode
Response
OK
Execution
Command
ATM<value> Parameter
<value> 0..9 mode
Reference
V.25ter
Note
No effect in GSM
2.2.12 +++ Switch from Data Mode or PPP Online Mode to Command Mode
+++ Switch from Data Mode or PPP Online Mode to Command Mode
Execution
Command
+++
Response
The +++ character sequence causes the TA to cancel the data flow over the
AT interface and switch to Command mode. This allows you to enter AT
Command while maintaining the data connection to the remote server.
OK
To prevent the +++ escape sequence from being misinterpreted as data, it
should comply to following sequence:
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 26 12/24/2010
1. No characters entered for T1 time (1 second)
2. "+++" characters entered with no characters in between (0.5 second)
3. No characters entered for T1 timer (0.5 second)
4. Switch to Command mode, otherwise go to step 1.
Parameter
Reference
V.25ter
Note
To return from Command mode back to data mode: Enter ATO.
2.2.13 ATO Switch from Command Mode to Data Mode
ATO Switch from Command Mode to Data Mode
Response
TA resumes the connection and switches back from Command mode to data
mode.
CONNECT
If connection is not successfully resumed
NO CARRIER
else
TA returns to data mode from Command mode CONNECT <text> Note:
<text> only if parameter setting ATX>0
Execution
Command
ATO[n]
Parameter
<n> 0 Switch from Command mode to data mode.
Reference
V.25ter
Note
2.2.14 ATP Select Pulse Dialling
ATP Select Pulse Dialling
Execution
Command
ATP
Response
OK
Reference
V.25ter
Note
No effect in GSM
2.2.15 ATQ Set Result Code Presentation Mode
ATQ Set Result Code Presentation Mode
Execution
Command
ATQ<n>
Response
This parameter setting determines whether or not the TA transmits any result
code to the TE. Information text transmitted in response is not affected by
this setting.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 27 12/24/2010
If <n>=0:
OK
If <n>=1:
(none)
Parameter
<n> 0 TA transmits result code
1 Result codes are suppressed and not transmitted
Reference
V.25ter
Note
2.2.16 ATS0 Set Number of Rings before Automatically Answering the Call
ATS0 Set Number of Rings before Automatically Answering the Call
Response
<n>
OK
Read Command
ATS0?
Parameter
See Write Command
Response
This parameter setting determines the number of rings before auto-answer.
OK
ERROR
Write Command
ATS0=<n>
Parameter
<n> 0 Automatic answering is disable.
1-255 Number of rings the modem will wait for before answering
the phone if a ring is detected.
Reference
V.25ter
Note
If <n> is set too high, the calling party may hang up before the call can be
answered automatically.
2.2.17 ATS3 Set Command Line Termination Character
ATS3 Set Command Line Termination Character
Response
<n>
OK
Read Command
ATS3?
Parameter
See Write Command
Write Command
ATS3=<n>
Response
This parameter setting determines the character recognized by TA to
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 28 12/24/2010
terminate an incoming Command line. The TA also returns this character in
output.
OK
ERROR
Parameter
<n> 13 Command line termination character
Reference
V.25ter
Note
Default 13 = CR. It only supports default value.
2.2.18 ATS4 Set Response Formatting Character
ATS4 Set Response Formatting Character
Response
<n>
OK
Read Command
ATS4?
Parameter
See Write Command
Response
This parameter setting determines the character generated by the TA for
result code and information text.
OK
ERROR
Write Command
ATS4=<n>
Parameter
<n> 10 Response formatting character
Reference
V.25ter
Note
Default 10 = LF. It only supports default value.
2.2.19 ATS5 Set Command Line Editing Character
ATS5 Set Command Line Editing Character
Response
<n>
OK
Read Command
ATS5?
Parameter
See Write Command
Write Command
ATS5=<n>
Response
This parameter setting determines the character recognized by TA as a
request to delete from the Command line the immediately preceding
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 29 12/24/2010
character.
OK
ERROR
Parameter
<n> 0-8-127 Response formatting character
Reference
V.25ter
Note
Default 8 = Backspace.
2.2.20 ATS6 Pause Before Blind Dialling
ATS6 Pause Before Blind Dialling
Read Command
ATS6?
Response
ERROR
Response
OK
ERROR
Write Command
ATS6=<n>
Parameter
<n> 0..999 Time
Reference
V.25ter
Note
No effect in GSM
2.2.21 ATS7 Set Number of Seconds to Wait for Connection Completion
ATS7 Set Number of Seconds to Wait for Connection Completion
Response
<n>
OK
Read Command
ATS7?
Parameter
See Write Command
Response
This parameter setting determines the amount of time to wait for the
connection completion in case of answering or originating a call.
OK
ERROR
Write Command
ATS7=<n>
Parameter
<n> 1-60-255 Number of seconds to wait for connection completion
Reference Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 30 12/24/2010
V.25ter z If called party has specified a high value for ATS0=<n>, call setup may
fail.
z The correlation between ATS7 and ATS0 is important
z Example: Call may fail if ATS7=30 and ATS0=20.
z ATS7 is only applicable to data call.
2.2.22 ATS8 Set Number of Seconds to Wait for Comma Dial Modifier Encountered in Dial
String of D Command
ATS8 Set Number of Seconds to Wait for Comma Dial Modifier Encountered in Dial
String of D Command
Response
<n>
OK
Read Command
ATS8?
Parameter
See Write Command
Response
OK
ERROR
Write Command
ATS8=<n>
Parameter
<n> 0-255 The value of this register determines how long the modem
should pause when it sees a comma in the dialing string.
Reference
V.25ter
Note
No effect in GSM
2.2.23 ATS10 Set Disconnect Delay after Indicating the Absence of Data Carrier
ATS10 Set Disconnect Delay after Indicating the Absence of Data Carrier
Response
<n>
OK
Read Command
ATS10?
Parameter
See Write Command
Response
This parameter setting determines the amount of time that the TA will
remain connected in absence of data carrier. If the data carrier is once more
detected before disconnecting, the TA remains connected.
OK
ERROR
Write Command
ATS10=<n>
Parameter
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 31 12/24/2010
<n> 1-15-254 Number of tenths seconds of delay
Reference
V.25ter
Note
2.2.24 ATT Select Tone Dialing
ATT Select Tone Dialing
Execution
Command
ATT
Response
OK
Reference
V.25ter
Note
No effect in GSM
2.2.25 ATV TA Response Format
ATV TA Response Format
Response
This parameter setting determines the contents of the header and trailer
transmitted with result codes and information responses.
When <value>=0
0
When <value>=1
OK
Execution
Command
ATV<value>
Parameter
<value> 0 Information response: <text><CR><LF>
Short result code format: <numeric code><CR>
1 Information response: <CR><LF><text><CR><LF>
Long result code format: <CR><LF><verbose code>
<CR><LF>
The result codes, their numeric equivalents and brief descriptions of the use
of each are listed in the following table.
Reference
V.25ter
Note
ATV1 ATV0 Description
OK 0 Acknowledges execution of a Command
CONNECT 1 A connection has been established; the DCE is moving
from Command state to online data state
RING 2 The DCE has detected an incoming call signal from
network
NO CARRIER 3 The connection has been terminated or the attempt to
establish a connection failed
ERROR 4 Command not recognized, Command line maximum
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 32 12/24/2010
length exceeded, parameter value invalid, or other
problem with processing the Command line
NO DIALTONE 6 No dial tone detected
BUSY 7 Engaged (busy) signal detected
NO ANSWER 8 "@" (Wait for Quiet Answer) dial modifier was used,
but remote ringing followed by five seconds of silence
was not detected before expiration of the connection
timer (S7)
PROCEEDING 9 An AT command is being processed
CONNECT
<text>
Manufacturer-
specific
Same as CONNECT, but includes
manufacturer-specific text that may specify DTE speed,
line speed, error control, data compression, or other
status
2.2.26 ATX Set CONNECT Result Code Format and Monitor Call Progress
ATX Set CONNECT Result Code Format and Monitor Call Progress
Response
This parameter setting determines whether or not the TA detected the
presence of dial tone and busy signal and whether or not TA transmits
particular result codes.
OK
ERROR
Execution
Command
ATX<value>
Parameter
<value> 0 CONNECT result code only returned, dial tone and busy
detection are both disabled.
1 CONNECT<text> result code only returned, dial tone and
busy detection are both disabled.
2 CONNECT<text> result code returned, dial tone
detection is enabled, busy detection is disabled.
3 CONNECT<text> result code returned, dial tone
detection is disabled, busy detection is enabled.
4 CONNECT<text> result code returned, dial tone and
busy detection are both enabled.
Reference
V.25ter
Note
2.2.27 ATZ Reset Default Configuration
ATZ Reset Default Configuration
Execution
Command
ATZ[<value>]
Response
TA sets all current parameters to the user defined profile.
OK
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 33 12/24/2010
ERROR
Parameter
<value> 0 Restore profile 0
1 Restore profile 1
Reference
V.25ter
Note
Parameter impacted by Z command:
Command Parameter name Default value
ATE <echo> 0x01
ATQ <result> 0x00
ATV <format> 0x01
ATX <result> 0x04
AT&C <behavior> 0x01
AT&D <behavior> 0x01
AT+IFC <TA_by_TE> 0x00
AT+IFC <TE_by_TA> 0x00
AT+FCLASS <class> 0x00
ATS0 <num> 0x00
ATS3 <char> 0x00
ATS4 <char> 0x0D
ATS5 <char> 0x0A
ATS7 <time> 0x08
ATS8 <time> 0x32
ATS10 <time> 0x0E
2.2.28 AT&C Set DCD Function Mode
AT&C Set DCD Function Mode
Response
This parameter determines how the state of circuit 109 (DCD) relates to the
detection of received line signal from the distant end.
OK
ERROR
Execution
Command
AT&C[<value>]
Parameter
<value> 0 DCD line is always ON
1 DCD line is ON only in the presence of data carrier
Reference
V.25ter
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 34 12/24/2010
2.2.29 AT&D Set DTR Function Mode
AT&D Set DTR Function Mode
Response
This parameter determines how the TA responds when circuit 108/2 (DTR)
is changed from the ON to the OFF condition during data mode.
OK
ERROR
Execution
Command
AT&D[<value>]
Parameter
<value> 0 TA ignores status on DTR.
1 ON->OFF on DTR: Change to Command mode with
remaining the connected call.
2 ON->OFF on DTR: Disconnect call, change to Command
mode. During state DTR = OFF is auto-answer off.
Reference
V.25ter
Note
2.2.30 AT&F Factory Defined Configuration
AT&F Factory Defined Configuration
Response
TA sets all current parameters to the manufacturer defined profile.
OK
Execution
Command
AT&F[<value>]
Parameter
<value> 0 Set all TA parameters to manufacturer defaults.
Reference
V.25ter
Note
Parameter impacted by &F command:
Command Parameter name Default value
ATE <echo> 0x01
ATQ <result> 0x00
ATV <format> 0x01
ATX <result> 0x04
AT+IFC <TA_by_TE> 0x00
AT+IFC <TE_by_TA> 0x00
ATS0 <num> 0x00
ATS3 <char> 0x0D
ATS4 <char> 0x0A
ATS5 <char> 0x08
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 35 12/24/2010
ATS7 <time> 0x64
ATS8 <time> 0x02
ATS10 <time> 0x0E
AT+CRLP <ver> 0x00
AT+CRLP <T4> 0x07
AT+CRLP <iws> 0x61
AT+CRLP <mws> 0x61
AT+CRLP <T1> 0x48
AT+CRLP <N2> 0x06
AT+CPBS <storage> 0x53 0x4D 0x00
AT+CSMP <fo> 0x11
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x18
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x00
AT+CSMP <fo> 0x11
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x18
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x00
AT+CSMP <fo> 0x11
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x18
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x00
AT+CSMP <vp> 0x00..0x00
AT+CSMP <pid> 0x00
AT+CSMP <dcs> 0x00
AT+CR <mode> 0x00
AT+CSTA <type> 0x81
AT+CBST <speed> 0x05 0x02 0x00
AT+CBST <name> 0x01 0x00
AT+CBST <ce> 0x01
AT+CRC <mode> 0x00
AT+CMOD <mode> 0x00
AT+CMEE <n> 0x00
AT+CREG <n> 0x00
AT+CGREG <n> 0x00
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 36 12/24/2010
AT+CSMS <service> 0x00
AT+CMGF <mode> 0x00
AT+CSDH <show> 0x00
AT+CSCS <chset> 0x00
AT+CLIR <n> 0x00
AT+CLIP <n> 0x00
AT+COLP <n> 0x00
2.2.31 AT&V Display Current Configuration
AT&V Display Current Configuration
Response
TA returns the current parameter setting.
<current configurations text>
OK
ERROR
Execution
Command
AT&V[<n>]
Parameter
<n> 0 Responses in numeric format
Reference
V.25ter
Note
2.2.32 AT&W Store Active Profile
AT&W Store Active Profile
Response
TA stores the current parameter setting in the user defined profile.
OK
ERROR
Execution
Command
AT&W[<n>]
Parameter
<n> 0 Store the current configuration in profile 0
1 Store the current configuration in profile 1
Reference
V.25ter
Note
The user defined profile is stored in non volatile memory.
Parameter stored by &W
Command Parameter name Displayedby &V
ATE <echo> Y
ATQ <result> Y
ATV <format> Y
ATX <result> Y
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 37 12/24/2010
AT&C <behavior> Y
AT&D <behavior> Y
AT+IFC <TA_by_TE> Y
AT+IFC <TE_by_TA> Y
AT+FCLASS <class> Y
ATS0 <num> Y
ATS3 <char> Y
ATS4 <char> Y
ATS5 <char> Y
ATS7 <time> Y
ATS8 <time> Y
ATS10 <time> Y
2.2.33 AT+GCAP Request Complete TA Capabilities List
AT+GCAP Request Complete TA Capabilities List
Response
TA reports a list of additional capabilities.
+GCAP: list of supported <name>s
OK
Execution
Command
AT+GCAP
Parameter
<name> +CGSM GSM function is supported
+FCLASS FAX function is supported
Reference
V.25ter
Note
The command can be executed only when the SIM card is present.
2.2.34 AT+GMI Request Manufacturer Identification
AT+GMI Request Manufacturer Identification
Response
OK
Test Command
AT+GMI=?
Parameter
Execution
Command
AT+GMI
TA reports one or more lines of information text which permit the user to
identify the manufacturer.
SIMCOM_Ltd
OK
Reference
V.25ter
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 38 12/24/2010
2.2.35 AT+GMM Request TA Model Identification
AT+GMM Request TA Model Identification
Test Command
AT+GMM=?
Response
OK
TA reports one or more lines of information text which permit the user to
identify the specific model of device.
<model>
OK
Execution
Command
AT+GMM
Parameter
<model> product model identification text
Reference
V.25ter
Note
2.2.36 AT+GMR Request TA Revision Identification of Software Release
AT+GMR Request TA Revision Identification of Software Release
Test Command
AT+GMR=?
Response
OK
TA reports one or more lines of information text which permit the user to
identify the revision of software release.
Revision: <revision>
OK
Execution
Command
AT+GMR
Parameter
<revision> Revision of software release
Reference
V.25ter
Note
2.2.37 AT+GOI Request Global Object Identification
AT+GOI Request Global Object Identification
Test Command
AT+GOI=?
Response
OK
Execution
Command
AT+GOI
Response
TA reports one or more lines of information text which permit the user to
identify the device, based on the ISO system for registering unique object
identifiers.
<Object Id>
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 39 12/24/2010
OK
Parameter
<Object Id> identifier of device type
see X.208, 209 for the format of <Object Id>
Reference
V.25ter
Note
2.2.38 AT+GSN Request TA Serial Number Identification (IMEI)
AT+GSN Request TA Serial Number Identification(IMEI)
Test Command
AT+GSN=?
Response
OK
Response
TA reports the IMEI (international mobile equipment identifier) number in
information text which permit the user to identify the individual ME device.
<sn>
OK
Execution
Command
AT+GSN
Parameter
<sn> IMEI of the telephone(International Mobile station Equipment
Identity)
Reference
V.25ter
Note
The serial number (IMEI) is varied by individual ME device.
2.2.39 AT+ICF Set TE-TA Control Character Framing
AT+ICF Set TE-TA Control Character Framing
Response
+ICF: (list of supported <format>s),(list of supported <parity>s)
OK
Test Command
AT+ICF=?
Parameters
See Write Command
Response
+ICF: <format>,<parity>
OK
Read Command
AT+ICF?
Parameters
See Write Command
Write Command
AT+ICF=<forma
t>,[<parity>]
Response
This parameter setting determines the serial interface character framing
format and parity received by TA from TE.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 40 12/24/2010
OK
Parameters
<format> 1 8 data 0 parity 2 stop
2 8 data 1 parity 1 stop
3 8 data 0 parity 1 stop
4 7 data 0 parity 2 stop
5 7 data 1 parity 1 stop
6 7 data 0 parity 1 stop
<parity> 0 odd
1 even
3 space (0)
Reference
V.25ter
Note
z The Command is applied for Command state;
z In <format> parameter, "0 parity" means no parity;
z The <parity> field is ignored if the <format> field specifies no parity
and string "+ICF: <format>,255" will be response to AT+ICF?
Command.
2.2.40 AT+IFC Set TE-TA Local Data Flow Control
AT+IFC Set TE-TA Local Data Flow Control
Response
+IFC: (list of supported <dce_by_dte>s),(list of supported
<dte_by_dce>s)
OK
Test Command
AT+IFC=?
Parameters
See Write Command
Response
+IFC: <dce_by_dte>,<dte_by_dce>
OK
Read Command
AT+IFC?
Parameters
See Write Command
Response
This parameter setting determines the data flow control on the serial
interface for data mode.
OK
Write Command
AT+IFC=<dce_b
y_dte>[,<dte_by
_dce>]
Parameters
<dce_by_dte> Specifies the method will be used by TE at receive of
data from TA
0 No flow control
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 41 12/24/2010
1 Software flow control
2 Hardware flow control
<dte_by_dce> Specifies the method will be used by TA at receive of
data from TE
0 No flow control
1 Software flow control
2 Hardware flow control
Reference
V.25ter
Note
2.2.41 AT+IPR Set TE-TA Fixed Local Rate
AT+IPR Set TE-TA Fixed Local Rate
Response
+IPR: (),(list of supported <rate>s)
OK
Test Command
AT+IPR=?
Parameter
See Write Command
Response
+IPR: <rate>
OK
Read Command
AT+IPR?
Parameter
See Write Command
Response
This parameter setting determines the data rate of the TA on the serial
interface. The rate of Command takes effect following the issuance of any
result code associated with the current Command line.
OK
Write Command
AT+IPR=<rate>
Parameter
<rate> Baud rate per second
0 (Auto-bauding)
1200
2400
4800
9600
19200
38400
57600
115200
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 42 12/24/2010
Reference
V.25ter
Note
Factory setting is AT+IPR=0auto-bauding.
2.2.41.1 Auto-bauding
Synchronization between DTE and DCE ensure that DTE and DCE are correctly synchronized and
the baud rate used by the DTE is detected by the DCE (= ME). To allow the baud rate to be
synchronized, simply issue an "AT" string. This is necessary when you start up the module while
auto-bauding is enabled. It is recommended to wait 3 to 5 seconds before sending the first AT
character. Otherwise undefined characters might be returned.
If you want to use auto-bauding and auto-answer at the same time, you can easily enable the
DTE-DCE synchronization, when you activate auto-bauding first and then configure the
auto-answer mode.
Restrictions on auto-bauding operation
z The serial interface has to be operated at 8 data bits, no parity and 1 stop bit (factory
setting).
z Only the strings "AT" or "At" (not "aT" or "at") can be detected when auto-bauding is
enabled.
z AT+IPR=0 setting to auto-bauding will take effect after module resets. If user wants to
change DTE baud rate during module is running, i.e. from 57600 to 4800, DTR shall be
used to urge auto-bauding progress. DTR shall be pulled up to invalid state at least 2
seconds by DTE and then pulled down to valid state. The step will urge auto-bauding
progress and DCE will synchronize its baud rate after it receives data from the serial port.
z Unsolicited Result Codes that may be issued before the ME detects the new baud rate (by
receiving the first AT Command string) will be sent at the previously detected baud rate.
z The Unsolicited Result Codes "RDY" and so on are not indicated when you start up the ME
while auto-bauding is enabled.
z It is not recommended to switch to auto-bauding from a baud rate that cannot be detected
by the auto-bauding mechanism (e.g. 300 baud). Responses to +IPR=0 and any commands
on the same line might be corrupted.
Auto-bauding and baud rate after restart
The most recently detected baud rate can not be stored when module is powered down.
2.2.42 AT+HVOIC Disconnect Voice Call Only
AT+HVOIC Disconnect Voice Call Only
Execution
Command
AT+HVOIC
Response
Disconnect existing voice call by local TE from Command line and
terminate call with existing PPP or CSD connection on.
OK
Reference
V.25ter
Note
3 AT Commands According to GSM07.07
3.1 Overview of AT Command According to GSM07.07
Command Description
AT+ CA CM ACCUMULATED CALL METER(ACM) RESET OR QUERY
AT+CAMM ACCUMULATED CALL METER MAXIMUM(ACM MAX) SET OR
QUERY
AT+CAOC ADVICE OF CHARGE
AT+CBST SELECT BEARER SERVICE TYPE
AT+CCFC CALL FORWARDING NUMBER AND CONDITIONS CONTROL
AT+CCWA CALL WAITING CONTROL
AT+CEER EXTENDED ERROR REPORT
AT+ CG MI REQUEST MANUFACTURER IDENTIFICATION
AT+CGMM REQUEST MODEL IDENTIFICATION
AT+ CG MR REQUEST TA REVISION IDENTIFICATION OF SOFTWARE
RELEASE
AT+CGSN REQUEST PRODUCT SERIAL NUMBER IDENTIFICATION
(IDENTICAL WITH +GSN)
AT+CSCS SELECT TE CHARACTER SET
AT+ CS TA SELECT TYPE OF ADDRESS
AT+CHLD CALL HOLD AND MULTIPARTY
AT+CIMI REQUEST INTERNATIONAL MOBILE SUBSCRIBER IDENTITY
AT+CLCC LIST CURRENT CALLS OF ME
AT+ CL CK FACILITY LOCK
AT+ CL IP CALLING LINE IDENTIFICATION PRESENTATION
AT+ CL IR CALLING LINE IDENTIFICATION RESTRICTION
AT+CMEE REPORT MOBILE EQUIPMENT ERROR
AT+ CO LP CONNECTED LINE IDENTIFICATION PRESENTATION
AT+COPS OPERATOR SELECTION
AT+ CPA S PHONE ACTIVITY STATUS
AT+CPBF FIND PHONEBOOK ENTRIES
AT+CPBR READ CURRENT PHONEBOOK ENTRIES
AT+CPBS SELECT PHONEBOOK MEMORY STORAGE
AT+ CP BW WRITE PHONEBOOK ENTRY
AT+ CP IN ENTER PIN
AT+ CP WD CHANGE PASSWORD
AT+CR SERVICE REPORTING CONTROL
AT+CRC SET CELLULAR RESULT CODES FOR INCOMING CALL
SIM300_ATC_V1.03 1 08.29.2008
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 44 12/24/2010
INDICATION
AT+CREG NETWORK REGISTRATION
AT+CRLP SELECT RADIO LINK PROTOCOL PARAMETERS
AT+CRSM RESTRICTED SIM ACCESS
AT+ CS Q SIGNAL QUALITY REPORT
AT+ FC LAS S FAX: SELECT, READ OR TEST SERVICE CLASS
AT+ FM I FAX: REPORT MANUFACTURED ID
AT+FMM FAX: REPORT MODEL ID
AT+ FM R FAX: REPORT REVISION ID
AT+ VT D TONE DURATION
AT+ VT S DTMF AND TONE GENERATION
AT+CMUX MULTIPLEXER CONTROL
AT+CNUM SUBSCRIBER NUMBER
AT+ CP OL PREFERRED OPERATOR LIST
AT+COPN READ OPERATOR NAMES
AT+CFUN SET PHONE FUNCTIONALITY
AT+CCLK CLOCK
AT+ CS IM GENERIC SIM ACCESS
AT+ CA LM ALERT SOUND MODE
AT+ CA LS ALERT SOUND SELECT
AT+CRSL RINGER SOUND LEVEL
AT+ CLV L LOUD SPEAKER VOLUME LEVEL
AT+ CM UT MUTE CONTROL
AT+ CP UC PRICE PER UNIT AND CURRENCY TABLE
AT+CCWE CALL METER MAXIMUM EVENT
AT+CBC BATTERY CHARGE
AT+CUSD UNSTRUCTURED SUPPLEMENTARY SERVICE DATA
AT+CSSN SUPPLEMENTARY SERVICES NOTIFICATION
3.2 Detailed Descriptions of AT Command According to GSM07.07
3.2.1 AT+CACM Accumulated Call Meter (ACM) Reset or Query
AT+CACM Accumulated Call Meter(ACM) Reset or Query
Test Command
AT+CACM=?
Response
OK
Read Command
AT+CACM?
Response
TA returns the current value of ACM.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 45 12/24/2010
+CACM: <acm>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Parameter
<acm> string type (string should be included in quotation marks);
three bytes of the current ACM value in hexa-decimal format
(e.g. "00001E" indicates decimal value 30)
000000 – FFFFFF
Response
TA resets the Advice of Charge related accumulated call meter (ACM)
value in SIM file EF (ACM). ACM contains the total number of home
units for both the current and preceding calls.
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CACM=<pa
sswd>
Parameter
<passwd> string type (string should be included in quotation marks):
SIM PIN2
Reference
GSM 07.07 [13]
Note
3.2.2 AT+CAMM Accumulated Call Meter Maximum (ACM max) Set or Query
AT+CAMM Accumulated Call Meter Maximum(ACM max) Set or Query
Test Command
AT+CAMM=?
Response
OK
Response
TA returns the current value of ACM max.
+CAMM: <acmmax>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CAMM?
Parameters
See Write Command
Write Command
AT+CAMM=<ac
mmax>[,<passwd
Response
TA sets the Advice of Charge related accumulated call meter maximum
value in SIM file EF (ACM max). ACM max contains the maximum
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 46 12/24/2010
number of home units allowed to be consumed by the subscriber.
OK
ERROR
If error is related to ME functionality:
+CME ERROR: <err>
>]
Parameters
<acmmax> string type (string should be included in quotation
marks); three bytes of the max. ACM value in
hex-decimal format (e.g. "00001E" indicates decimal
value 30)
000000 disable ACMmax feature
000001-FFFFFF
<passwd> string type (string should be included in quotation marks)
SIM PIN2
Reference
GSM 07.07 [13]
Note
3.2.3 AT+CAOC Advice of Charge
AT+CAOC Advice of Charge
Response
+CAOC: (list of supported <mode>s)
OK
Test Command
AT+CAOC=?
Parameters
See Write Command
Response
+CAOC: <mode>
OK
Read Command
AT+CAOC?
Parameters
See Write Command
Write Command
AT+CAOC=<mo
de>
Response
TA sets the Advice of Charge supplementary service function mode.
If <mode>=0, TA returns the current call meter value
+CAOC: <ccm>
OK
If <mode>=1, TA deactivates the unsolicited reporting of CCM value
OK
If <mode>=2, TA activates the unsolicited reporting of CCM value
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 47 12/24/2010
OK
ERROR
If error is related to ME functionality:
+CME ERROR: <err>
Parameters
<mode> 0 Query CCM value
1 Deactivate the unsolicited reporting of CCM value
2 Activate the unsolicited reporting of CCM value
<ccm> String type (string should be included in quotation marks);
three bytes of the current CCM value in hex-decimal format
(e.g. "00001E" indicates decimal value 30); bytes are
similarly coded as ACMmax value in the SIM
000000-FFFFFF
Reference
GSM 07.07 [13]
Note
3.2.4 AT+CBST Select Bearer Service Type
AT+CBST Select Bearer Service Type
Response
+CBST: (list of supported <speed>s),(list of supported <name>s),(list of
supported <ce>s)
OK
Test Command
AT+CBST=?
Parameters
See Write Command
Response
+CBST: <speed>,<name>,<ce>
OK
Read Command
AT+CBST?
Parameters
See Write Command
Response
TA selects the bearer service <name> with data rate <speed>, and the
connection element <ce> to be used when data calls are originated.
OK
ERROR
Write Command
AT+CBST=<spee
d>[,<name>[,<ce
>]]
Parameters
<speed> 0 Auto-bauding (automatic selection of the speed; this
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 48 12/24/2010
setting is possible in case of 3.1kHz modern and
non-transparent service)
7 9600 bps (V.32)
71 9600 bps (V.110 or X.31 flag stuffing)
Supported if UMTS_FTR is activated
<name> 0 Data circuit asynchronous (UDI or 3.1 kHz modem)
<ce> 1 Non-transparent
Reference
GSM 07.07 [14]
Note
z GSM 02.02[1]: lists the allowed combinations of the sub parameters
z It only supports the speed of 9600bps when in non-transparent mode.
3.2.5 AT+CCFC Call Forwarding Number and Conditions Control
AT+CCFC Call Forwarding Number and Conditions Control
Response
+CCFC: (list of supported <reason>s)
OK
Test Command
AT+CCFC=?
Parameter
See Write Command
Write Command
AT+CCFC =
<reason>,
<mode>
[, <number> [,
<type> [,<class>
[, <subaddr>
[,<satype>
[,time]]]]]]
Response
TA controls the call forwarding supplementary service. Registration,
erasure, activation, deactivation, and status query are supported.
Only ,<reads> and <mode> should be entered with mode (0-2,4)
If <mode>2 and Command successful
OK
If <mode>=2 and Command successful (only in connection with <reads> 0
–3)
For registered call forwarding numbers:
when <mode>=2 and command successful:
+CCFC: <status>,<class1>
[,<number>,<type>[,<subaddr>,<satype>[,<time>]]]
[<CR><LF>+CCFC: <status>,<class2>
[,<number>,<type>[,<subaddr>,<satype>[,<time>]]][…]
OK
If no call forwarding numbers are registered (and therefore all classes are
inactive):
+CCFC: <status>, <class>
OK
where <status>=0 and <class>=7
If error is related to ME functionality:
+CME ERROR: <err>
SIM900 AT Command Manual
Parameters
<reason> 0 Unconditional
1 Mobile busy
2 No reply
3 Not reachable
4 All call forwarding
5 All conditional call forwarding
<mode> 0 Disable
1 Enable
2 Query status
3 Registration
4 Erasure
<number> string type (Phone number of forwarding address in format
specified by <type>)
<type> type of address
<subaddr> string type (subaddress of format specified by <satype>)
<satype> type of sub-address in integer
<class> 1 Voice (telephony)
2 Data (refers to all bearer services; with <mode>=2 this
may refer only to some bearer service if TA does not
support values 16, 32, 64 and 128)
4 Fax (facsimile services)
7 All classes
<time> 1..30 When "no reply" is enabled or queried, this gives the
time in seconds to wait before call is forwarded,
default value is 20.Supported only if it is multiples
of 5.
<status>
0 Not active
1 Active
Reference
GSM07.07
Note
3.2.6 AT+CCWA Call Waiting Control
AT+CCWA Call Waiting Control
Response
+CCWA: (list of supported <n>s)
OK
Test Command
AT+CCWA=?
Parameter
See Write Command
Read Command Response
SIM900_AT Command Manual_V1.03 49 12/24/2010
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 50 12/24/2010
+CCWA: <n>
OK
AT+CCWA?
Parameter
See Write Command
Response
TA controls the Call Waiting supplementary service. Activation,
deactivation and status query are supported.
If <mode>2 and Command successful
OK
If <mode>=2 and Command successful
+CCWA:<status>,<class1>[<CR><LF>+CCWA:<status>,<class2>[...]]
OK
ERROR
If error is related to ME functionality:
+CME ERROR: <err>
Note: <status>=0 should be returned only if service is not active for any
<class> i.e. +CCWA: 0, 7 will be returned in this case.
When mode=2, all active call waiting classes will be reported. In this mode
the Command is abortable by pressing any key.
Parameters
<n> 0 Disable presentation of an unsolicited result code
1 Enable presentation of an unsolicited result code
<mode> When <mode> parameter not given, network is not
interrogated
0 Disable
1 Enable
2 Query status
<class> is a sum of integers each representing a class of information
1 voice (telephony)
2 data (refers to all bearer services; with <mode>=2 this
may refer only to some bearer service if TA does not
support values 16, 32, 64 and 128)
4 fax (facsimile services)
7 default(1+2+4)
<status> 0 not active
1 enable
Write Command
AT+CCWA=<n>[,
<mode>[,<class>]]
Unsolicited result code
RING
+CCWA: <number>,<type>,<class>[,<alpha>]
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 51 12/24/2010
Parameters
<number> String type (string should be included in quotation marks)
phone number of calling address in format specified by
<type>
<type> Type of address octet in integer format;
129 Unknown type (IDSN format number)
161 National number type (IDSN format)
145 International number type (ISDN format )
177 Network specific number (ISDN format)
<alpha> optional string type(string should be included in quotation
marks) alphanumeric representation of <number>
corresponding to the entry found in phone book.
Reference
GSM07.07
Note
3.2.7AT+CEER Extended Error Report
AT+CEER Extended Error Report
Response
+CEER: (list of supported <n>s)
OK
Test Command
AT+CEER=?
Parameter
See Write Command
Response
+CEER: <n>
OK
Read Command
AT+CEER?
Parameter
See Write Command
Response
OK
Write Command
AT+CEER=<n>
Parameter
<n> 0 The reason for last call release as text code
1 The reason for last call release as number code
Execution
Command
AT+CEER
Response
TA returns an extended report of the reason for the last call release.
+CEER: <report>
OK
SIM900 AT Command Manual
Parameter
<report> If AT+CEER=0, return <c>
<c> a string that represents the Cause
If AT+CEER=1, return
CauseSelect: <cs> Cause:<c>
<cs> number representing the CauseSelect
<c> number representing the Cause
Parameters
CauseSelect <cs> Cause <c>(number) <c>(string)
0 (No cause) 0 (No cause)
16 (Service provider) 0 (Unknown)
1 (Not Allowed)
2 (No cause)
6 (Wrong parameter)
9 (Network access not allowed)
20 (all call instances are used)
21 (ACM over ACM Max)
22 (invalid AOC element)
23 (SIM increase not allowed)
24 (switch off)
25 (Unknown call id)
28 (barred)
65 (Local cause) 1 (state error)
2 (no call entity)
3 (wrong TI)
6 (DTMF buffer overflow)
7 (call disconnected)
17 (No cell available)
32 (Local rejection)
33 (PLMN not allowed)
34 (emergency call not possible)
35 (authentication rejected)
36 (network rejection)
37 (LA not allowed)
38 (Local timeout)
SIM900_AT Command Manual_V1.03 52 12/24/2010
SIM900 AT Command Manual
39 (server congestion)
40 (local data rejection)
48 (failed replace PDP context)
66 (MM network cause) See [24.008]
67 (CC network cause) See [24.008]
69 (RP cause) See [24.008]
71 (SIM cause) 0 (Unknown problem)
1 (Memory problem)
2 (File Id not found)
6 (Increase problem)
7 (Technical problem)
11 (Command not allowed)
15 (SIM card out)
73 (SM cause) See [24.008]
Reference
GSM 07.07 [13]
Note
3.2.8 AT+CGMI Request Manufacturer Identification
AT+CGMI Request Manufacturer Identification
Test Command
AT+CGMI=?
Response
OK
Response
TA returns manufacturer identification text.
<manufacturer>
OK
Execution
Command
AT+CGMI
Parameter
<manufacturer> the ID of manufacturer
Reference
GSM 07.07 [13]
Note
3.2.9 AT+CGMM Request Model Identification
AT+CGMM Request Model Identification
Test Command Response
SIM900_AT Command Manual_V1.03 53 12/24/2010
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 54 12/24/2010
AT+CGMM=? OK
Response
TA returns product model identification text.
<model>
OK
Execution
Command
AT+CGMM
Parameter
<model> product model identification text
Reference
GSM 07.07 [13]
Note
3.2.10 AT+CGMR Request TA Revision Identification of Software Release
AT+CGMR Request TA Revision Identification of Software Release
Test Command
AT+CGMR=?
Response
OK
Response
TA returns product software version identification text.
Revision: <revision>
OK
Execution
Command
AT+CGMR
Parameter
<revision> product software version identification text
Reference
GSM 07.07 [13]
Note
3.2.11 AT+CGSN Request Product Serial Number Identification (Identical with +GSN)
AT+CGSN Request Product Serial Number Identification (Identical with +GSN)
Test Command
AT+CGSN=?
Response
OK
Response
see +GSN
<sn>
OK
Execution
Command
AT+CGSN
Parameter
<sn> International mobile equipment identity (IMEI)
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 55 12/24/2010
3.2.12 AT+CSCS Select TE Character Set
AT+CSCS Select TE Character Set
Response
+CSCS: (list of supported <chset>s)
OK
Test Command
AT+CSCS=?
Parameter
<chset> "GSM" GSM 7 bit default alphabet (3GPP TS 23.038);
"UCS2" 16-bit universal multiple-octet coded character set
(ISO/IEC10646); UCS2 character strings are
converted to hexadecimal numbers from 0000 to
FFFF; e.g. "004100620063" equals three 16-bit
characters with decimal values 65, 98 and 99
"IRA" International reference alphabet (ITU-T T.50)
"HEX" Character strings consist only of hexadecimal
numbers from 00 to FF;
"PCCP" PC character set Code
"PCDN" PC Danish/Norwegian character set
"8859-1" ISO 8859 Latin 1 character set
Response
+CSCS: <chset>
OK
Read Command
AT+CSCS?
Parameter
See Test Command
Response
Sets which character set <chset> are used by the TE. The TA can then
convert character strings correctly between the TE and ME character sets.
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CSCS=<chse
t>
Parameter
See Test Command
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 56 12/24/2010
3.2.13 AT+CSTA Select Type of Address
AT+CSTA Select Type of Address
Response
+CSTA: (list of supported <type>s)
OK
Test Command
AT+CSTA=?
Parameter
See Write Command
Response
+CSTA: <type>
OK
Read Command
AT+CSTA?
Parameter
<type> Current address type setting.
Response
OK
If <type> is not in the parameter range:
ERROR
Write Command
AT+CSTA=<type
>
Parameter
<type> Type of address octet in integer format;
129 Unknown type (IDSN format number)
161 National number type (IDSN format)
145 International number type (ISDN format )
177 Network specific number (ISDN format)
Reference
GSM 07.07 [13]
Note
The ATD Command overrides this setting when a number is dialed.
3.2.14 AT+CHLD Call Hold and Multiparty
AT+CHLD Call Hold and Multiparty
Response
+CHLD: (list of supported <n>s)
OK
Test Command
AT+CHLD=?
Parameter
See Write Command
Write Command
AT+CHLD=<n>
Response
TA controls the supplementary services Call Hold, Multiparty and Explicit
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 57 12/24/2010
Call Transfer. Calls can be put on hold, recovered, released, added to
conversation, and transferred.
Note These supplementary services are only applicable to tele service 11
(Speech: Telephony).
OK
If error is related to ME functionality:
+CME ERROR: <err>
Parameter
<n> 0 Releases all held calls or sets User Determined User Busy
(UDUB) for a waiting call
1 Releases all active calls (if any exist) and accepts the other
(held or waiting) call.
1x Releases a specific active call x
2 Place all active calls on hold (if any) and accept the other
(held or waiting) call.
2x Places all active calls on hold except call X with which
communication shall be supported.
3 Adds a held call to the conversation.
4 Connects the two calls and disconnects the subscriber from
both calls(ECT)
6 Swap operation(retrieves the held call and holds the active
call). Not applicable for calls engaged in a multiparty
operation(+CME ERROR returned)
6x Retrieves the specified held call x. Not applicable for calls
engaged in a multiparty operation (+CME ERROR
returned)
7x Holds the specified active call x. Not applicable for calls
engaged in a multiparty operation (+CME ERROR
returned)
8x Releases the specified call x (whatever its state).
9x Aborts MO speech call x setup without releasing other
calls. Possible if OK result code is sent before call is
connected: allowed if *PSCSSC mode = enabled and
+COLP = disabled.
Reference Note
3.2.15 AT+CIMI Request International Mobile Subscriber Identity
AT+CIMI Request International Mobile Subscriber Identity
Test Command
AT+CIMI=?
Response
OK
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 58 12/24/2010
Response
TA returns <IMSI>for identifying the individual SIM which is attached to
ME.
<IMSI>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Execution
Command
AT+CIMI
Parameter
<IMSI> International Mobile Subscriber Identity (string without
double quotes)
Reference
GSM 07.07 [13]
Note
3.2.16 AT+CLCC List Current Calls of ME
AT+CLCC List Current Calls of ME
Response
+CLCC: (0,1)
OK
Test Command
AT+CLCC=?
Parameters
See Write Command
Response
+CLCC: <n>
OK
Read Command
AT+CLCC?
Parameters
See Write Command
Response
OK
Write Command
AT+CLCC=<n>
Parameter
<n> 0 Don’t report a list of current calls of ME automatically
when the current call status changes.
1 Report a list of current calls of ME automatically when the
current call status changes.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 59 12/24/2010
Response
TA returns a list of current calls of ME.
Note: If Command succeeds but no calls are available, no information
response is sent to TE.
[+CLCC: <id1>,<dir>,<stat>,<mode>,<mpty>[,<number>,<type
>,<alphaID>][<CR><LF>+CLCC:
<id2>,<dir>,<stat>,<mode>,<mpty>
[,<number>,<type>,<alphaID>][...]]]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Execution
Command
AT+CLCC
Parameters
<idx> 1..7 Call identification number
This number can be used in +CHLD command operations
<dir> 0 Mobile originated (MO) call
1 Mobile terminated (MT) call
<stat> State of the call:
0 active
1 held
2 dialing (MO call)
3 alerting (MO call)
4 incoming (MT call)
5 waiting (MT call)
6 disconnect
<mode> Bearer/tele service:
0 voice
1 data
2 fax
<mpty> 0 Call is not one of multiparty (conference) call parties
1 Call is one of multiparty (conference) call parties
<number> String type(string should be included in quotation marks)
phone number in format specified by <type>.
<type> Type of address
<alphaId> String type(string should be included in quotation marks)
alphanumeric representation of <number> corresponding
to the entry found in phone book.
Reference
GSM 07.07
[13][14]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 60 12/24/2010
3.2.17 AT+CLCK Facility Lock
AT+CLCK Facility Lock
Response
+CLCK: (list of supported <fac>s)
OK
Test Command
AT+CLCK=?
Parameter
See Write Command
Response
This Command is used to lock, unlock or interrogate a ME or a network
facility <fac>. Password is normally needed to do such actions. When
querying the status of a network service (<mode>=2) the response line for
‘not active’ case (<status>=0) should be returned only if service is not
active for any <class>.
If <mode>2 and Command is successful
OK
If <mode>=2 and Command is successful
+CLCK: <status>[,<class1>[<CR><LF>+CLCK:
<status>,<class2>[…]]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CLCK=
<fac>,<mode>
[,<passwd>
[,<class>]]
Parameters
<fac>
"AO" BAOC (Barr All Outgoing Calls)
"OI" BOIC (Barr Outgoing International Calls)
"OX" BOIC-exHC (Barr Outgoing International Calls
except to Home Country)
"AI" BAIC (Barr All Incoming Calls)
"IR" BIC-Roam (Barr Incoming Calls when Roaming
outside the home country)
"AB" All Barring services
"AG" All out oing barring services
"AC" All in Coming barring services
"FD" SIM card or active application in the UICC (GSM or
USIM) fixed dialling memory feature (if PIN2
authentication has not been done during the current
session, PIN2 is required as <passwd>)
"SC" SIM (lock SIM/UICC card) (SIM/UICC asks
password
in
MT power-up and when this lock
command issued) Correspond to PIN1 code.
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 61 12/24/2010
"PN" Network Personalization, Correspond to NCK code
"PU" Network subset Personalization
Correspond to NSCK code
"PP" Service Provider Personalization
Correspond to SPCK code
<mode> 0 unlock
1 lock
2 query status
<passwd> String type (Shall be the same as password specified for the
facility from the MT user interface or with command Change
Password +CPWD)
<class> 1 voice (telephony)
2 data refers to all bearer services; with <mode>=2 this
may refer only to some bearer service if TA does not
support values 16, 32, 64 and 128)
4 fax
(facsimile services)
7 all classes
<status> 0 Not active
1 Active
Reference
GSM 07.07 [14]
Note
CME errors if SIM not inserted or PIN is not entered.
3.2.18 AT+CLIP Calling Line Identification Presentation
AT+CLIP Calling Line Identification Presentation
Response
+CLIP: (list of supported <n>s)
OK
Test Command
AT+CLIP=?
Parameter
See Write Command
Response
+CLIP: <n>, <m>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CLIP?
Parameters
See Write Command
Write Command
AT+CLIP=<n>
Response
TA enables or disables the presentation of the CLI at the TE. It has no
effect on the execution of the supplementary service CLIP in the network.
OK
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 62 12/24/2010
If error is related to ME functionality:
+CME ERROR: <err>
Parameters
<n> 0 Disable +CLIP notification.
1 Enable +CLIP notification.
<m> 0 CLIP not provisioned
1 CLIP provisioned
2 unknown (e.g. no network, etc.)
Unsolicited Result Code
When the presentation of the CLI at the TE is enabled (and calling
subscri
b
er allows), an unsolicited result code is returned after every RING
(or +CRING: <type>) at a mobile terminating call.
+CLIP: <number>,<type> [,<subaddr>,<satype>,<alphaId>,<CLI
validity>]
Parameters
<number> String type (string should be included in quotation marks)
phone number of calling address in format specified by
<type>
<type> Type of address octet in integer format;
129 Unknown type(IDSN format number)
161 National number type(IDSN format)
145 International number type(ISDN format )
177 Network specific number(ISDN format)
<subaddr> string type (subaddress of format specified by <satype>)
<satype> Integer type(type of subaddress)
<alphaId> string type (string should be included in quotation marks)
alphanumeric representation of <number> corresponding
to the entry found in phone book
<CLI validity> 0 CLI valid
1 CLI has been withheld by the originator
2 CLI is not available due to interworking problems
or limitations of originating network
Reference Note
3.2.19 AT+CLIR Calling Line Identification Restriction
AT+CLIR Calling Line Identification Restriction
Test Command
AT+CLIR=?
Response
+CLIR: (list of supported <n>s)
OK
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 63 12/24/2010
Parameter
See Write Command
Response
+CLIR: <n>, <m>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CLIR?
Parameters
See Write Command
Response
TA restricts or enables the presentation of the CLI to the called party when
originating a call.
The Command overrides the CLIR subscription (default is restricted or
allowed) when temporary mode is provisioned as a default adjustment for
all following outgoing calls. This adjustment can be revoked by using the
opposite Command.
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CLIR=<n>
Parameters
<n> (parameter sets the adjustment for outgoing calls):
0 presentation indicator is used according to the subscription of
the CLIR service.
1 CLIR invocation
2 CLIR suppression
<m> (parameter shows the subscriber CLIR service status in the
network):
0 CLIR not provisioned
1 CLIR provisioned in permanent mode
2 unknown (e.g. no network, etc.)
3 CLIR temporary mode presentation restricted
4 CLIR temporary mode presentation allowed
Reference Note
3.2.20 AT+CMEE Report Mobile Equipment Error
AT+CMEE Report Mobile Equipment Error
Test Command
AT+CMEE=?
Response
+CMEE: (list of supported <n>s)
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 64 12/24/2010
OK
Parameter
See Write Command
Response
+CMEE: <n>
OK
Read Command
AT+CMEE?
Parameter
See Write Command
Response
TA disables or enables the use of result code +CME ERROR: <err> as an
indication of an error relating to the functionality of the ME.
OK
If error is related to ME functionality:
+CME ERROR:<err>
Write Command
AT+CMEE=<n>
Parameter
<n> 0 Disable +CME ERROR: <err> result code and use ERROR
instead.
1 Enable +CME ERROR: <err> result code and use numeric
<err>
2 Enable +CME ERROR: <err> result code and use verbose
<err> values
Reference
GSM 07.07 [13]
Note
3.2.21 AT+COLP Connected Line Identification Presentation
AT+COLP Connected Line Identification Presentation
Response
+COLP: (list of supported <n>s)
OK
Test Command
AT+COLP=?
Parameter
See Write Command
Response
+COLP: <n>,<m>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+COLP?
Parameters
See Write Command
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 65 12/24/2010
Response
TA enables or disables the presentation of the COL (Connected Line) at the
TE for a mobile originated call. It has no effect on the execution of the
supplementary service COLR in the network.
Intermediate result code is returned from TA to TE before any +CR or
V.25ter responses.
OK
If error is related to ME functionality:
+CME ERROR: <err>
Parameters
<n> (parameter sets/shows the result code presentation status in the
TA):
0 Disable +COLP notification
1 Enable +COLP notification
<m> (parameter shows the subscriber COLP service status in the
network):
0 COLP not provisioned
1 COLP provisioned
2 Unknown (e.g. no network, etc.)
Intermediate result code
When enabled (and called subscriber allows), an intermediate result code is
returned before any +CR or V.25ter responses:
+COLP: <number>,<type>[,<subaddr>,<satype> ,<alphaId>]
Write Command
AT+COLP=<n>
Parameters
<number> string type (string should be included in quotation marks)
phone number of format specified by <type>
<type> Type of address octet in integer format;
129 Unknown type(IDSN format number)
161 National number type(IDSN format)
145 International number type(ISDN format )
177 Network specific number(ISDN format)
<subaddr> string type (string should be included in quotation marks)
sub address of format specified by <satype>
<satype> Type of sub address octet in integer format (refer GSM
04.08 [8] sub clause 10.5.4.8)
<alphaId> string type (string should be included in quotation marks)
alphanumeric representation of <number> corresponding
to the entry found in phone book.
Reference Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 66 12/24/2010
3.2.22 AT+COPS Operator Selection
AT+COPS Operator Selection
Response
TA returns a list of quadruplets, each representing an operator present in
the network. Any of the formats may be unavailable and should then be an
empty field. The list of operators shall be in order: home network,
networks referenced in SIM, and other networks.
+COPS: (list of supported<stat>, long alphanumeric <oper>, short
alphanumeric <oper>, numeric <oper>)s [,,(list of supported
<mode>s),(list of supported <format>s)]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Test Command
AT+COPS=?
Parameters
See Write Command
Response
TA returns the current mode and the currently selected operator. If no
operator is selected, <format> and <oper> are omitted.
+COPS: <mode>[,<format>, <oper>]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+COPS?
Parameters
See Write Command
Response
TA forces an attempt to select and register the GSM network operator. If
the selected operator is not available, no other operator shall be selected
(except <mode>=4). The selected operator name format shall apply to
further read commands (+COPS?).
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+COPS =
<mode>,
[<format>[,<oper
>]]
Parameters
<stat> 0 unknown
1 operator available
2 operator current
3 operator forbidden
<oper> Refer to [27.007]
operator in format as per <format>
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 67 12/24/2010
<mode> 0 automatic mode; <oper> field is ignored
1 manual (<oper> field shall be present, and <AcT>
optionally)
4 manual/automatic (<oper> field shall be present); if
manual selection fails, automatic mode (<mode>=0) is
entered
<format> 0 long format alphanumeric <oper>
1 short format alphanumeric <oper>
2 numeric <oper>; GSM Location Area Identification
number
Reference
GSM 07.07 [14]
Note
3.2.23 AT+CPAS Phone Activity Status
AT+CPAS Phone Activity Status
Response
+CPAS: (list of supported <pas>s)
OK
Test Command
AT+CPAS=?
Parameter
See Execution Command
Response
TA returns the activity status of ME.
+CPAS: <pas>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Execution
Command
AT+CPAS
Parameter
<pas> 0 Ready (MT allows commands from TA/TE)
2 Unknown (MT is not guaranteed to respond to
instructions)
3 Ringing (MT is ready for commands from TA/TE, but the
ringer is active)
4 Call in progress (MT is ready for commands from TA/TE,
but a call is in progress)
Reference
GSM 07.07 [13]
Note
3.2.24 AT+CPBF Find Phonebook Entries
AT+CPBF Find Phonebook Entries
Test Command Response
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 68 12/24/2010
+CPBF: maximum length of field <nlength>,maximum length of field
<tlength>
OK
If error is related to ME functionality:
+CME ERROR: <err>
AT+CPBF=?
Parameters
See Write Command
Response
TA returns phone book entries (from the current phone book memory
storage selected with +CPBS) which contains alphanumeric string
<findtext>.
[+CPBF:<index1>,<number>,<type>,<text>][----]
<CR><LF>[+CBPF:<index2>,<number>,<type>,<text>]
OK
Write Command
AT+CPBF=[<find
text>]
Parameters
<findtext> string type(string should be included in quotation marks)
field of maximum length <tlength> in current TE character
set specified by +CSCS.
<index1> integer type values in the range of location numbers of
phone book memory
<index2> integer type values in the range of location numbers of
phone book memory
<number> string type(string should be included in quotation marks)
phone number of format <type>
<type> type of address octet in integer format ;
129 Unknown type (IDSN format number)
161 National number type (IDSN format)
145 International number type (ISDN format )
177 Network specific number (ISDN format)
<text> string type (string should be included in quotation marks)
field of maximum length <tlength> in current TE character
set specified by +CSCS.
<nlength> integer type value indicating the maximum length of field
<number>
<tlength> integer type value indicating the maximum length of field
<text>
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 69 12/24/2010
3.2.25 AT+CPBR Read Current Phonebook Entries
AT+CPBR Read Current Phonebook Entries
Response
TA returns location range supported by the current storage as a compound
value and the maximum lengths of <number> and <text> fields.
+CPBR: (list of supported <index>s), <nlength>, <tlength>
OK
Test Command
AT+CPBR=?
Parameters
<index> location number
<nlength> max. length of phone number
<tlength> max. length of text for number
Response
TA returns phone book entries in location number range <index1>...
<index2> from the current phone book memory storage selected with
+CPBS. If <index2> is left out, only location <index1> is returned.
+CPBR:<index1>,<number>,<type>,<text>[<CR><LF>+CPBR: .....
<CR><LF>+CPBR: <index2>, <number>, <type>, <text>]
OK
Write Command
AT+CPBR=
<index1>
[, <index2>]
Parameters
<index1> read as of this location number
<index2> read to this location number
<number> phone number
<type> type of number
<text> text for phone number in current TE character set specified
by +CSCS.
Reference
GSM 07.07 [13]
Note
3.2.26 AT+CPBS Select Phonebook Memory Storage
AT+CPBS Select Phonebook Memory Storage
Response
+CPBS: (list of supported <storage>s)
OK
Test Command
AT+CPBS=?
Parameter
See Write Command
Read Command
AT+CPBS?
Response
+CPBS: <storage>[,<used>,<total>]
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 70 12/24/2010
OK
Parameters
See Write Command
Response
TA selects current phone book memory storage, which is used by other
phone book commands.
OK
Write Command
AT+CPBS=<stora
ge>
Parameters
<storage> "DC" ME dialed calls list(+CPBW may not be applicable
for this storage)(same as LD)
"EN" SIM (or MT) emergency number (+CPBW is not
be applicable for this storage)
"FD" SIM fix dialing-phone book. If a SIM card is
present or if a UICC with an active GSM
application is present, the information in EFFDN
under DFTelecom is selected
"MC" MT missed (unanswered received) calls list
(+CPBW may not be applicable for this storage)
"ON" SIM (or MT) own numbers (MSISDNs) list
(reading of this storage may be available through
+CNUM also). When storing information in the
SIM/UICC, if a SIM card is present or if a UICC
with an active GSM application is present, the
information in EFMSISDN under DFTelecom is
selected.
"RC" MT received calls list (+CPBW may not be
applicable for this storage)
"SM" SIM/UICC phonebook. If a SIM card is present or
if a UICC with an active GSM application is present, the
EFADN under DFTelecom is selected.
"LA" Last Number All list (LND/LNM/LNR)
"ME" ME phonebook
"BN" SIM barred dialed number
"SD" SIM service dial number
"VM" SIM voice mailbox
"LD" SIM last-dialing-phone book
<used> integer type value indicating the total number of used
locations in selected memory
<total> integer type value indicating the total number of locations
in selected memory
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 71 12/24/2010
3.2.27 AT+CPBW Write Phonebook Entry
AT+CPBW Write Phonebook Entry
Response
TA returns location range supported by the current storage, the maximum
length of <number> field, supported number formats of the storage, and
the maximum length of <text> field.
+CPBW: (list of supported <index>s), <nlength>, (list of supported
<type>s), <tlength>
OK
Test Command
AT+CPBW=?
Parameters
See Write Command
Response
TA writes phone book entry in location number <index> in the current
phone book memory storage selected with +CPBS. Entry fields written are
phone number <number> (in the format <type>) and text <text> associated
with the number. If those fields are omitted, phone book entry is deleted. If
<index> is left out, but <number> is given, entry is written to the first free
location in the phone book.
OK
Write Command
AT+CPBW=
<index>
[, <number>,
[<type>, [<text>]]]
Parameters
<nlength> Max length of phone number
<tlength> Max length of text for number
<index> Location number
<number> Phone number
<type> Type of number;
129 National number type (IDSN format
161 National number type (IDSN format)
145 International number type (ISDN format )
177 Network specific number (ISDN format)
<text> String type(string should be included in quotation marks):
text for phone number in current TE character set specified
by +CSCS.
Note: The following characters in <text> must be entered via the
escape sequence:
GSM char. Seq. Seq.(hex) Note
\ \5C 5C 35 43 (backslash)
" \22 5C 32 32 (string delimiter)
BSP \08 5C 30 38 (backspace)
NULL \00 5C 30 30 (GSM null)
‘0’ (GSM null) may cause problems for application layer
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 72 12/24/2010
software when reading string lengths.
Reference
GSM 07.07 [13]
Note
3.2.28 AT+CPIN Enter PIN
AT+CPIN Enter PIN
Test Command
AT+CPIN=?
Response
OK
Response
TA returns an alphanumeric string indicating whether some password is
required or not.
+CPIN: <code>
OK
Read Command
AT+CPIN?
Parameter
<code>
READY MT is not pending for any password
SIM PIN MT is waiting SIM PIN to be given
SIM PUK MT is waiting for SIM PUK to be given
PH_SIM PIN ME is waiting for phone to SIM card (antitheft)
PH_SIM PUK ME is waiting for SIM PUK (antitheft)
SIM PIN2 PIN2, e.g. for editing the FDN book possible
only if preceding Command was acknowledged
with +CME ERROR:17
SIM PUK2 possible only if preceding Command was
acknowledged with error +CME ERROR: 18.
Response
TA stores a password which is necessary before it can be operated (SIM
PIN, SIM PUK, PH-SIM PIN, etc.).
If the PIN required is SIM PUK or SIM PUK2, the second pin is required.
This second pin, <new pin>, is used to replace the old pin in the SIM.
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CPIN=<pin>
[, <new pin>]
Parameters
<pin> string type; password
<new pin> string type; If the PIN required is SIM PUK or SIMPUK2:
new password
Reference Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 73 12/24/2010
GSM 07.07 [13]
3.2.29 AT+CPWD Change Password
AT+CPWD Change Password
Response
TA returns a list of pairs which present the available facilities and the
maximum length of their password.
+CPWD: (list of supported <fac>s, list of supported <pwdlength>s)
OK
Test Command
AT+CPWD=?
Parameters
<fac> see Write Command
<pwdlength> integer max. length of password
Response
TA sets a new password for the facility lock function.
OK
Write Command
AT+CPWD =
<fac>, <oldpwd>,
<newpwd>
Parameters
<fac>
"AO" BAOC (Barr All Outgoing Calls)
"OI" BOIC (Barr Outgoing International Calls)
"OX" BOIC-exHC (Barr Outgoing International Calls
except to Home Country)
"AI" BAIC (Barr All Incoming Calls)
"IR" BIC-Roam (Barr Incoming Calls when Roaming
outside the home country)
"AB" all Barring services
"P2" SIM PIN2
"SC" SIM (lock SIM/UICC card) (SIM/UICC asks password
in MT power-up and when this lock command
issued) Correspond to PIN1 code.
<oldpwd> string type (string should be included in quotation marks):
password specified for the facility from the user interface
or with Command. If an old password has not yet been
set, <oldpwd> is not to enter.
<newpwd> string type (string should be included in quotation marks):
new password
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 74 12/24/2010
3.2.30 AT+CR Service Reporting Control
AT+CR Service Reporting Control
Response
+CR: (list of supported <mode>s)
OK
Test Command
AT+CR=?
Parameter
See Write Command
Response
+CR: <mode>
OK
Read Command
AT+CR?
Parameter
See Write Command
Response
TA controls whether or not intermediate result code +CR: <serv> is
returned from the TA to the TE at a call set up.
OK
Parameter
<mode> 0 Disable
1 Enable
Intermediate result code
If enabled, an intermediate result code is transmitted at the point during
connect negotiation at which the TA has determined which speed and
quality of service will be used, before any error control or data
compression reports are transmitted, and before any final result code (e.g.
CONNECT) is transmitted.
+CR:<serv>
Write Command
AT+CR=<mode>
Parameters
<serv> ASYNC asynchronous transparent
SYNC synchronous transparent
REL ASYNC asynchronous non-transparent
REL SYNC synchronous non-transparent
GPRS for GPRS
Reference
GSM 07.07 [13]
Note
3.2.31 AT+CRC Set Cellular Result Codes for Incoming Call Indication
AT+CRC Set Cellular Result Codes for Incoming Call Indication
Test Command Response
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 75 12/24/2010
+CRC: (list of supported <mode>s)
OK
AT+CRC=?
Parameter
See Write Command
Response
+CRC: <mode>
OK
Read Command
AT+CRC?
Parameter
See Write Command
Response
TA controls whether or not the extended format of incoming call
indication is used.
OK
Parameter
<mode> 0 Disable extended format
1 Enable extended format
Unsolicited Result Code
When enabled, an incoming call is indicated to the TE with unsolicited
result code +CRING: <type> instead of the normal RING.
Write Command
AT+CRC=<mode
>
Parameter
<type> ASYNC asynchronous transparent
SYNC synchronous transparent
REL ASYNC asynchronous non-transparent
REL SYNC synchronous non-transparent
FAX facsimile
VOICE voice
Reference
GSM 07.07 [13]
Note
3.2.32 AT+CREG Network Registration
AT+CREG Network Registration
Response
+CREG: (list of supported <n>s)
OK
Test Command
AT+CREG=?
Parameter
See Write Command
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 76 12/24/2010
Read Command
AT+CREG?
Response
TA returns the status of result code presentation and an integer <stat>
which shows whether the network has currently indicated the registration
of the ME. Location information elements <lac> and <ci> are returned
only when <n>=2 and ME is registered in the network.
+CREG: <n>,<stat>[,<lac>,<ci>]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Response
TA controls the presentation of an unsolicited result code +CREG: <stat>
when <n>=1 and there is a change in the ME network registration status.
OK
Parameters
<n> 0 Disable network registration unsolicited result code
1 Enable network registration unsolicited result code
+CREG: <stat>
2 Enable network registration unsolicited result code with
location information +CREG: <stat>[,<lac>,<ci>]
<stat> 0 Not registered, MT is not currently searching a new
operator to register to
1 Registered, home network
2 Not registered, but MT is currently searching a new
operator to register to
3 Registration denied
4 Unknown
5 Registered, roaming
<lac> String type (string should be included in quotation marks);
two byte location area code in hexadecimal format
<ci> String type (string should be included in quotation marks);
two byte cell ID in hexadecimal format
Unsolicited Result Code
If <n>=1 and there is a change in the MT network registration status
+CREG: <stat>
If <n>=2 and there is a change in the MT network registration status or a
change of the network cell:
+CREG: <stat>[,<lac>,<ci>]
Write Command
AT+CREG=[<n>
]
Parameters
See Write Command
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 77 12/24/2010
3.2.33 AT+CRLP Select Radio Link Protocol Parameters
AT+CRLP Select Radio Link Protocol Parameters
Response
TA returns values supported. RLP versions 0 and 1 share the same
parameter set. TA returns only one line for this set (where <verx> is not
present).
+CRLP: (list of supported <iws>s),(list of supported <mws>s),(list of
supported <T1>s),(list of supported <N2>s),(list of supported
<ver1>s),(list of supported <T4>s)
OK
Test Command
AT+CRLP=?
Parameters
See Write Command
Response
TA returns current settings for RLP version. RLP versions 0 and 1 share
the same parameter set. TA returns only one line for this set (where
<verx> is not present).
+CRLP: <iws>,<mws>,<T1>,<N2>,<ver1>,<T4>
OK
Read Command
AT+CRLP?
Parameters
See Write Command
Response
TA sets radio link protocol (RLP) parameters used when non-transparent
data calls are setup.
OK
Write Command
AT+CRLP=<iws
>[,<mws>[,<T1>[
,<N2>[,<ver>[,<T
4>]]]]] Parameters
<iws> 0-61 Interworking window size (IWF to MS)
<mws> 0-61 Mobile window size(MS to IWF)
<T1> 44-255 Acknowledgment timer T1 in 10 ms units
<N2> 1-255 Retransmission attempts N2
<verx> 0 RLP version number
<T4> 7 Re-sequencing period in integer format, in units of 10 ms.
Reference
GSM 07.07 [13]
Note
3.2.34 AT+CRSM Restricted SIM Access
AT+CRSM Restricted SIM Access
Test Command
AT+CRSM=?
Response
OK
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 78 12/24/2010
Response
+CRSM: <sw1>, <sw2> [,<response>]
OK
ERROR
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CRSM=<Co
mmand>[,<fileId
>[,<P1>,<P2>,<P
3>[,<data>]]]
Parameters
<Command>
176 READ BINARY
178 READ RECORD
192 GET RESPONSE
214 UPDATE BINARY
220 UPDATE RECORD
242 STATUS
All other values are reserved; refer GSM 11.11.
<fileId> integer type; this is the identifier for an elementary data file on
SIM. Mandatory for every Command except STATUS
<P1>,<P2>,<P3> integer type, range 0 – 255
Parameters to be passed on by the ME to the SIM; refer GSM
11.11.
<data> information which shall be written to the SIM (hex-decimal
character format)
<sw1>, <sw2> integer type, range 0 - 255
Status information from the SIM about the execution
of the actual Command. These parameters are delivered to the
TE in both cases, on successful or failed execution of the
Command; refer GSM 11.11.
<response> response of a successful completion of the Command
previously issued (hexadecimal character format)
Reference
GSM 07.07
GSM 11.11
Note
3.2.35 AT+CSQ Signal Quality Report
AT+CSQ Signal Quality Report
Test Command
AT+CSQ=?
Response
+CSQ: (list of supported <rssi>s),(list of supported <ber>s)
OK
Execution
Command
AT+CSQ
Response
+CSQ: <rssi>,<ber>
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 79 12/24/2010
OK
If error is related to ME functionality:
+CME ERROR: <err>
Execution Command returns received signal strength indication <rssi>
and channel bit error rate <ber> from the ME. Test Command returns
values supported by the TA.
Parameters
<rssi>
0 -115 dBm or less
1 -111 dBm
2...30 -110... -54 dBm
31 -52 dBm or greater
99 not known or not detectable
<ber> (in percent):
0...7 As RXQUAL values in the table in GSM 05.08 [20]
subclause 7.2.4
99 Not known or not detectable
Reference
GSM 07.07 [13]
Note
3.2.36 AT+FCLASS FAX: Select, Read or Test Service Class
AT+FCLASS FAX: Select, Read or Test Service Class
Response
+FCLASS: (list of supported <class>s)
OK
Test Command
AT+FCLASS=?
Parameter
See Write Command
Response
+FCLASS: <class>
OK
Read Command
AT+FCLASS?
Parameter
See Write Command
Response
TA sets a particular mode of operation (data fax). This causes the TA to
process information in a manner suitable for that type of information
OK
Write Command
AT+FCLASS=
<class>
Parameter
<n> 0 data
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 80 12/24/2010
1 fax class 1 (TIA-578-A)
Reference
GSM 07.07 [13]
Note
3.2.37 AT+FMI FAX: Report Manufactured ID
AT+FMI FAX: Report Manufactured ID
Test Command
AT+FMI =?
Response
OK
Response
TA reports one or more lines of information text which permit the user to
identify the manufacturer.
<manufacturer Id>
OK
Execution
Command
AT+FMI
Parameter
<manufacturer Id> the ID of manufacturer
Reference
EIA/TIA-578-D
Note
3.2.38 AT+FMM FAX: Report Model ID
AT+FMM FAX: Report Model ID
Test Command
AT+FMM =?
Response
OK
Response
TA reports one or more lines of information text which permit the user to
identify the specific model of device.
<model Id>
OK
Execution
Command
AT+FMM
Parameter
<model Id> the ID of model
Reference
EIA/TIA-578-D
Note
3.2.39 AT+FMR FAX: Report Revision ID
AT+FMR FAX: Report Revision ID
Test Command
AT+FMR =?
Response
OK
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 81 12/24/2010
Response
TA reports one or more lines of information text which permit the user to
identify the version, revision level or data or other information of the
device.
Revision:<Revision Id>
OK
Execution
Command
AT+FMR
Parameter
<Revision Id> the version, revision level or data or other information
of the device.
Reference
EIA/TIA-578-D
Note
3.2.40 AT+VTD Tone Duration
AT+VTD Tone Duration
Response
+VTD: (list of supported <n>s)
OK
Test Command
AT+VTD=?
Parameter
See Write Command
Response
+VTD: <n>
OK
Read Command
AT+VTD?
Parameter
See Write Command
Response
This Command refers to an integer <n> that defines the length of tones
emitted as a result of the +VTS Command. This does not affect the D
Command.
OK
Write Command
AT+VTD = <n>
Parameter
<n> 1-255 duration of the tone in 1/10 seconds
Reference
GSM 07.07 [13]
Note
3.2.41 AT+VTS DTMF and Tone Generation
AT+VTS DTMF and Tone Generation
Test Command
AT+VTS=?
Response
+VTS: (list of supported <dtmf>s), ,(list of supported <duration>s)
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 82 12/24/2010
OK
Parameters
See Write Command
Write Command
Generate tone
Duration is set by
+VTD
AT+VTS=<dtmf-
string>
Response
This Command allows the transmission of DTMF tones and arbitrary
tones in voice mode. These tones may be used (for example) when
announcing the start of a recording period.
Note: D is used only for dialing.
OK
If error is related to ME functionality:
+CME ERROR: <err>
Note: The Command is writing only.
Parameters
<dtmf-string> which has a max length of 20 characters, must be entered
between double quotes ("") and consists of combinations of the following
separated by commas. But a single character does not require quotes.
1) <dtmf> A single ASCII characters in the set 0-9, #,*, A-D. This is
interpreted as a sequence of DTMF tones whose duration is set by the
+VTD Command.
2) {<dtmf>, <duration>} This is interpreted as a DTMF tone whose
duration is determined by <duration>.
<duration> duration of the tone in 1/10 seconds range :1-255
Reference
GSM 07.07 [13]
Note
3.2.42 AT+CMUX Multiplexer Control
AT+CMUX Multiplexer Control
Response
+CMUX: list of supported (<mode>s),(<subset>s),(<port_spe
ed>s),(<N1>s),(<T1>s),(<N2>s),(<T2>s),(<T3>s),(<k>s)
OK
Test Command
AT+CMUX=?
Parameters
See Write Command
Read Command
AT+CMUX ?
Response:
+CMUX:[<mode>[,<subset>[,<port_speed>[,<N1>[,<T1>[,<N2>[,<T2
>[,<T3>[,<k>]]]]]]]]]
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 83 12/24/2010
OK
ERROR
Parameters
See Write Command
Response
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CMUX=<mo
de>[,<subset>[,<
port_speed>[,<N
1>[,<T1>[,<N2>[,
<T2>[,<T3>[,<k>
]]]]]]]]
Parameters
<mode> multiplexer transparency mechanism
0 Basic option
<subset> the way in which the multiplexer control channel is set up
0 UIH frames used only
<port_speed> transmission rate
1 9 600 bits/t
2 19 200 bits/t
3 38 400 bits/t
4 57 600 bits/t
5 115 200bit/s
6 230 400 bits/t
7 460 800 bits/t
proprietary values, available if MUX NEW PORT
SPEED FTR is activated
8 921 600 bits/t
Proprietary values, available if MUX NEW PORT
SPEED FTR is activated
<N1> maximum frame size
1-32768 Default: 127
<T1> acknowledgement timer in units of ten milliseconds
1-255 Default:10 (100 ms)
<N2> maximum number of re-transmissions
0-100 Default:3
<T2> response timer for the multiplexer control channel in units of
ten milliseconds
2-255 Default:30
<T3> wake up response timers in seconds
1-255 Default:10
<k> window size, for Advanced operation with Error Recovery
options
1-7 Default:2
Reference
GSM 07.07 [13]
Note
The multiplexing transmission rate is according to the current serial baud
rate. It is recommended to enable multiplexing protocol under 115200
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 84 12/24/2010
bit/s baud rate
Multiplexer control channels are listed as follows:
Channel Number Type DLCI
None Multiplexer Control 0
1 07.07 and 07.05 1
2 07.07 and 07.05 2
3 07.07 and 07.05 3
4 07.07 and 07.05 4
3.2.43 AT+CNUM Subscriber Number
AT+CNUM Subscriber Number
Test Command
AT+CNUM=?
Response
OK
Response
+CNUM: [<alpha1>],<number1>,<type1>[,<speed>,<service>]
[<CR><LF>+CNUM:[<alpha2>],<number2>,<type2>[,<speed>,<serv
ice>]
[...]]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Execution
Command
AT+CNUM
Parameters
<alphax> optional alphanumeric string associated with <numberx>;
used character set should be the one selected with
Command Select TE Character Set +CSCS
<numberx> string type (string should be included in quotation marks)
phone number of format specified by <typex>
<typex> type of address octet in integer format (refer GSM04.08[8]
subclause 10.5.4.7)
<speed> as defined by the +CBST Command
<service> (service related to the phone number: )
0 asynchronous modem
1 synchronous modem
2 PAD Access (asynchronous)
3 Packet Access (synchronous)
4 Voice
5 Fax
Reference
GSM 07.07 [13]
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 85 12/24/2010
3.2.44 AT+CPOL Preferred Operator List
AT+CPOL Preferred Operator List
Response
+CPOL: (list of supported <index>s),(list of supported <format>s)
OK
Test Command
AT+CPOL=?
Parameters
See Write Command
Response
+CPOL: <index1>,<format>,<oper1>
[<CR><LF>+CPOL: <index2>,<format>,<oper2>[…]]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CPOL?
Parameters
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CPOL=<ind
ex>[,<format>,<o
per>]
Parameters
<index> integer type: order number of operator in SIM preferred
operator list
<format> indicates whether alphanumeric or numeric
format used (see +COPS Command)
0 long format alphanumeric <oper>
1 short format alphanumeric <oper>
2 numeric <oper>
<oper> string type(string should be included in quotation marks)
Reference
GSM 07.07 [13]
Note
3.2.45 AT+COPN Read Operator Names
AT+COPN Read Operator Names
Test Command
AT+COPN=?
Response
OK
Execution
Command
AT+COPN
Response
+COPN: <numeric1>,<alpha1>
[<CR><LF>+COPN: <numeric2>,<alpha2>
[…]]
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 86 12/24/2010
OK
If error is related to ME functionality:
+CME ERROR: <err>
Parameters
<numericn> string type (string should be included in quotation marks):
operator in numeric format (see +COPS)
<alphan> string type (string should be included in quotation marks):
operator in long alphanumeric format (see +COPS)
Reference
GSM 07.07 [13]
Note
3.2.46 AT+CFUN Set Phone Functionality
AT+CFUN Set Phone Functionality
Response
+CFUN: (list of supported <fun>s),(list of supported <rst>s)
OK
If error is related to ME functionality:
+CME ERROR: <err>
Test Command
AT+CFUN=?
Parameters
See Write Command
Response
+CFUN: <fun>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CFUN?
Parameters
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CFUN=<fun
>,[<rst>]
Parameters
<fun> 0 minimum functionality
1 full functionality (Default)
4 disable phone both transmit and receive RF circuits
<rst> 0 Do not reset the MT before setting it to <fun> power
level
1 Reset the MT before setting it to <fun> power level
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 87 12/24/2010
Reference
GSM 07.07 [13]
Note
z Minimum functionality mode(AT+CFUN=0)and RF disabled
functionality mode (AT+CFUN=4) cannot be switched to each other.
z The <fun> power level will be written to flash except minimum
functionality.
z AT+CFUN=1,1 can be used to reset module purposely. Response
string "OK" will be returned after module resets if baud rate is set to
fixed baud rate.
3.2.47 AT+CCLK Clock
AT+CCLK Clock
Test Command
AT+CCLK=?
Response
OK
Response
+CCLK: <time>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CCLK?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CCLK=<tim
e>
Parameter
<time> string type(string should be included in quotation marks)
value; format is "yy/MM/dd,hh:mm:ss±zz", where characters
indicate year (two last digits),month, day, hour, minutes,
seconds and time zone (indicates the difference, expressed in
quarters of an hour, between the local time and GMT; range
-47...+48). E.g. 6th of May 1994, 22:10:00 GMT+2 hours
equals to "94/05/06,22:10:00+08"
Reference
GSM 07.07 [13]
Note
3.2.48 AT+CSIM Generic SIM Access
AT+CSIM Generic SIM Access
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 88 12/24/2010
Test Command
AT+CSIM=?
Response
OK
Response
+CSIM: <length>,<response>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CSIM=<leng
th>,<Command>
Parameters
<length> integer type: length of characters sent to the TE in
<Command> or <response> (i.e. twice the number of
octets in the raw data)
<Command> string type(string should be included in quotation
marks): hex format: GSM 11.11 SIM Command sent
from the ME to the SIM
<response> string type(string should be included in quotation
marks): hex format: GSM 11.11 response from SIM to
<Command>
Reference
GSM 07.07 [13]
Note
3.2.49 AT+CALM Alert Sound Mode
AT+CALM Alert Sound Mode
Response
+CALM: (list of supported <mode>s)
OK
If error is related to ME functionality:
+CME ERROR: <err>
Test Command
AT+CALM=?
Parameter
See Write Command
Response
+CALM: <mode>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CALM?
Parameter
See Write Command
Write Command Response
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 89 12/24/2010
OK
If error is related to ME functionality:
+CME ERROR: <err>
AT+CALM=<mo
de>
Parameter
<mode> 0 normal mode
1 silent mode (all sounds from ME are prevented)
Reference
GSM 07.07 [13]
Note
If CALM is set to silent mode before, when user sets CALM to normal
mode during an incoming call, the module maintains silent this time. But
next time the normal mode works.
3.2.50 AT+CALS Alert Sound Select
AT+CALS Alert Sound Select
Response
+CALS: (list of supported <n>s)
OK
If error is related to ME functionality:
+CME ERROR: <err>
Test Command
AT+CALS=?
Parameter
See Write Command
Response
+CALS: <n>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CALS?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CALS=<n>
Parameter
<n> 0-19 alert sound type
Reference
Note
3.2.51 AT+CRSL Ringer Sound Level
AT+CRSL Ringer Sound Level
Test Command Response
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 90 12/24/2010
+CRSL: (list of supported <level>s)
OK
If error is related to ME functionality:
+CME ERROR: <err>
AT+CRSL=?
Parameter
See Write Command
Response
+CRSL: <level>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CRSL?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CRSL=<leve
l>
Parameter
<level> integer type value (0-4) with manufacturer specific range
(smallest value represents the lowest sound level)
0 LEVEL OFF
1 LEVEL LOW
2 LEVEL MEDIUM
3 LEVEL HIGH
4 LEVEL CRESCENDO
Reference
GSM 07.07 [13]
Note
It is related to the command AT+CLVL.
3.2.52 AT+CLVL Loud Speaker Volume Level
AT+CLVL Loud Speaker Volume Level
Response
+CLVL: (list of supported <level>s)
OK
If error is related to ME functionality:
+CME ERROR: <err>
Test Command
AT+CLVL=?
Parameter
See Write Command
Read Command Response
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 91 12/24/2010
+CLVL: <level>
OK
If error is related to ME functionality:
+CME ERROR: <err>
AT+CLVL?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CLVL=<leve
l>
Parameter
<level> 0-100 integer type value with manufacturer specific range
(smallest value represents the lowest sound level)
Reference
GSM 07.07 [13]
Note
3.2.53 AT+CMUT Mute Control
AT+CMUT Mute Control
Response
+CMUT: (list of supported <n>s)
OK
Test Command
AT+CMUT=?
Parameter
See Write Command
Response
+CMUT: <n>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CMUT?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CMUT=<n>
Parameter
<n> 0 mute off
1 mute on
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 92 12/24/2010
Reference
GSM 07.07 [13]
Note
Only during a call this command can be set successfully.
3.2.54 AT+CPUC Price Per Unit and Currency Table
AT+CPUC Price Per Unit and Currency Table
Test Command
AT+CPUC=?
Response
OK
Response
+CPUC: <currency>,<ppu>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CPUC?
Parameters
See Write Command
Response
OK
+CME ERROR: <err>
Write Command
AT+CPUC=<cur
rency>,<ppu>[,<
passwd>] Parameters
<currency> string type (string should be included in quotation marks);
three-character currency code (e.g. "GBP", "DEM");
character set as specified by Command Select TE
Character Set +CSCS
<ppu> string type (string should be included in quotation marks);
price per unit; dot is used as a decimal separator(e.g.
"2.66")
<passwd> string type (string should be included in quotation marks);
SIM PIN2
Reference
GSM 07.07 [13]
Note
3.2.55 AT+CCWE Call Meter Maximum Event
AT+CCWE Call Meter Maximum Event
Response
+CCWE: (list of supported <mode>s)
OK
If error is related to ME functionality:
+CME ERROR: <err>
Test Command
AT+CCWE=?
Parameter
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 93 12/24/2010
See Write Command
Response
+CCWE: <mode>
OK
If error is related to ME functionality:
+CME ERROR: <err>
Read Command
AT+CCWE?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Parameter
<mode> 0 Disable call meter warning event
1 Enable call meter warning event
Write Command
AT+CCWE=<m
ode>
Unsolicited result codes supported:
+CCWV Shortly before the ACM (Accumulated Call Meter)
maximum value is reached, an unsolicited result code
+CCWV will be sent, if enabled by this command. The
warning is issued approximately when 5 seconds call time
remains. It is also issued when starting a call if less than 5 s
call time remains.
Reference
GSM 07.07 [13]
Note
GSM 07.07 specifies 30 seconds, so SIMCom deviates from the
specification.
3.2.56 AT+CBC Battery Charge
AT+CBC Battery Charge
Response
+CBC: (list of supported <bcs>s),(list of supported <bcl>s),(<voltage>)
OK
Test Command
AT+CBC=?
Parameters
See Execution Command
Execution
Command
AT+CBC
Response
+CBC: <bcs>, <bcl>,<voltage>
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 94 12/24/2010
OK
If error is related to ME functionality:
+CME ERROR: <err>
Parameters
<bcs> charge status
0 ME is not charging
1 ME is charging
2 Charging has finished
<bcl> battery connection level
1...100 battery has 1-100 percent of capacity remaining
vent
<voltage> battery voltage(mV)
Reference
GSM 07.07 [13]
Note
This command depends on hardware and only be used when battery is
charging.
3.2.57 AT+CUSD Unstructured Supplementary Service Data
AT+CUSD Unstructured Supplementary Service Data
Response
+CUSD: (list of supported <n>s)
OK
Test Command
AT+CUSD=?
Parameter
See Write Command
Response
+CUSD: <n>
OK
Read Command
AT+CUSD?
Parameter
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CUSD=<n>[,
<str>[,<dcs>]]
Parameters
<n> a numeric parameter which indicates control of the unstructured
supplementary service data
0 disable the result code presentation in the TE
1 enable the result code presentation in the TE
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 95 12/24/2010
2 cancel session (not applicable to read Command response)
<str> string type(string should be included in quotation marks)
USSD-string
<dcs> Cell Broadcast Data Coding Scheme in integer format
(default 0)
Reference
GSM 03.38 [25]
Note
3.2.58 AT+CSSN Supplementary Services Notification
AT+CSSN Supplementary Services Notification
Response
+CSSN: (list of supported <n>s),(list of supported <m>s)
OK
Test Command
AT+CSSN=?
Parameters
See Write Command
Response
+CSSN: <n>,<m>
OK
Read Command
AT+CSSN?
Parameters
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+CSSN=<n>[,
<m>]
Parameters
<n> a numeric parameter which indicates whether to show the
+CSSI:<code1>[,<index>] result code presentation status
after a mobile originated call setup
0 disable
1 enable
<m> a numeric parameter which indicates whether to show the
+CSSU:<code2> result code presentation status during a
mobile terminated call setup or during a call, or when a
forward check supplementary service notification is received.
0 disable
1 enable
<code1> 0 unconditional call forwarding is active
1 some of the conditional call forwarding are active
2 call has been forwarded
3 call is waiting
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 96 12/24/2010
4 this is a CUG call (also <index> present)
5 outgoing calls are barred
6 incoming calls are barred
7 CLIR suppression rejected
<index> closed user group index
<code2> 0 this is a forwarded call
1 this is a CUG call (also <index> present) (MT call
setup)
2 call has been put on hold (during a voice call)
3 call has been retrieved (during a voice call)
4 multiparty call entered (during a voice call)
5 call on hold has been released (this is not a SS
notification) (during a voice call)
6 forward check SS message received (can be received
whenever)
7 call is being connected (alerting) with the remote party
in alerting state in explicit call transfer operation (during
a voice call)
8 call has been connected with the other remote party in
explicit call transfer operation (also number and
subaddress parameters may be present) (during a voice
call or MT call setup)
9 this is a deflected call (MT call setup)
Reference
Note
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 97 12/24/2010
4 AT Commands According to GSM07.05
The GSM 07.05 commands are for performing SMS and CBS related operations. SIM900 supports
both Text and PDU modes.
4.1 Overview of AT Commands According to GSM07.05
Command Description
AT+CMGD DELETE SMS MESSAGE
AT+ CM GF SELECT SMS MESSAGE FORMAT
AT+ CM GL LIST SMS MESSAGES FROM PREFERRED STORE
AT+ CM GR READ SMS MESSAGE
AT+ CM GS SEND SMS MESSAGE
AT+ CM GW WRITE SMS MESSAGE TO MEMORY
AT+CMSS SEND SMS MESSAGE FROM STORAGE
AT+ CN MI NEW SMS MESSAGE INDICATIONS
AT+CPMS PREFERRED SMS MESSAGE STORAGE
AT+CRES RESTORE SMS SETTINGS
AT+CSAS SAVE SMS SETTINGS
AT+ CS CA SMS SERVICE CENTER ADDRESS
AT+CSCB SELECT CELL BROADCAST SMS MESSAGES
AT+CSDH SHOW SMS TEXT MODE PARAMETERS
AT+CSMP SET SMS TEXT MODE PARAMETERS
AT+CSMS SELECT MESSAGE SERVICE
4.2 Detailed Descriptions of AT Commands According to GSM07.05
4.2.1 AT+CMGD Delete SMS Message
AT+CMGD Delete SMS Message
Response
+CMGD: (list of supported <index>s),(list of supported <delflag>s)
OK
Test Command
AT+CMGD=?
Parameters
See Write Command
Write Command
AT+CMGD=<in
dex>[,<delflag>]
Response
TA deletes message from preferred message storage <mem1> location
<index>.
OK
ERROR
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 98 12/24/2010
If error is related to ME functionality:
+CMS ERROR:<err>
Parameters
<index> integer type; value in the range of location numbers supported
by the associated memory
<delflag> 0 Delete the message specified in <index>
1 Delete all read messages from preferred message storage,
leaving unread messages and stored mobile originated
messages (whether sent or not) untouched
2 Delete all read messages from preferred message storage
and sent mobile originated messages, leaving unread
messages and unsent mobile originated messages
untouched
3 Delete all read messages from preferred message storage,
sent and unsent mobile originated messages leaving unread
messages untouched
4 Delete all messages from preferred message storage
including unread messages
Reference
GSM 07.05
Note
4.2.2 AT+CMGF Select SMS Message Format
AT+CMGF Select SMS Message Format
Response
+CMGF: (list of supported <mode>s)
OK
Test Command
AT+CMGF=?
Parameter
See Write Command
Response
+CMGF: <mode>
OK
Read Command
AT+CMGF?
Parameter
See Write Command
Response
TA sets parameter to deNote which input and output format of messages to
use.
OK
Write Command
AT+CMGF=<mo
de>
Parameter
<mode> 0 PDU mode
1 text mode
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 99 12/24/2010
Reference
GSM 07.05
Note
4.2.3 AT+CMGL List SMS Messages from Preferred Store
AT+CMGL List SMS Messages from Preferred Store
Response
+CMGL: (list of supported <stat>s)
OK
Test Command
AT+CMGL=?
Parameter
See Write Command
Parameters
1) If text mode:
<stat> "REC UNREAD" Received unread messages
"REC READ" Received read messages
"STO UNSENT" Stored unsent messages
"STO SENT" Stored sent messages
"ALL" All messages
<mode> 0 normal
1 not change status of the specified SMS record
2) If PDU mode:
<stat> 0 Received unread messages
1 Received read messages
2 Stored unsent messages
3 Stored sent messages
4 All messages
<mode> 0 normal
1 not change status of the specified SMS record
Write Command
AT+CMGL=<sta
t>[,<mode>]
Response
TA returns messages with status value <stat> from message storage
<mem1> to the TE. If status of the message is 'received unread', status in the
storage changes to 'received read'.
1) If text mode (+CMGF=1) and Command successful:
for SMS-SUBMITs and/or SMS-DELIVERs:
+CMGL:
<index>,<stat>,<oa/da>,[<alpha>],[<scts>][,<tooa/toda>,<length>]<CR
><LF><data>[<CR><LF>
+CMGL:
<index>,<stat>,<da/oa>,[<alpha>],[<scts>][,<tooa/toda>,<length>]<CR
><LF><data>[...]]
for SMS-STATUS-REPORTs:
+CMGL:
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 100 12/24/2010
<index>,<stat>,<fo>,<mr>,[<ra>],[<tora>],<scts>,<dt>,<st>[<CR><LF
>
+CMGL:
<index>,<stat>,<fo>,<mr>,[<ra>],[<tora>],<scts>,<dt>,<st>[...]]
for SMS-COMMANDs:
+CMGL: <index>,<stat>,<fo>,<ct>[<CR><LF>
+CMGL: <index>,<stat>,<fo>,<ct>[...]]
for CBM storage:
+CMGL:<index>,<stat>,<sn>,<mid>,<page>,<pages><CR><LF><data
><CR><LF>
+CMGL:
<index>,<stat>,<sn>,<mid>,<page>,<pages><CR><LF><data>[...]]
OK
2) If PDU mode (+CMGF=0) and Command successful:
+CMGL:<index>,<stat>,[<alpha>],<length><CR><LF><pdu><CR><L
F>
+CMGL: <index>,<stat>,[alpha],<length><CR><LF><pdu>[...]]
OK
3)If error is related to ME functionality:
+CMS ERROR: <err>
Parameters
<alpha> string type(string should be included in quotation marks)
alphanumeric representation of <da> or <oa> corresponding to
the entry found in MT phonebook; implementation of this
feature is manufacturer specific; used character set should be
the one selected with Command Select TE Character Set
+CSCS (see definition of this Command in TS 07.07)
<da> GSM 03.40 TP-Destination-Address Address-Value field in
string format; BCD numbers (or GSM default alphabet
characters) are converted to characters of the currently selected
TE character set (refer Command+CSCS in TS 07.07); type of
address given by <toda>
<data> In the case of SMS: GSM 03.40 TP-User-Data in text mode
responses; format:
- if <dcs> indicates that GSM 03.38 default alphabet is used and
<fo> indicates that GSM 03.40
TPUser-Data-Header-Indication is not set:
- if TE character set other than "HEX" (refer Command Select
TE Character Set +CSCS in TS 07.07):ME/TA
converts GSM alphabet into current TE character set
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 101 12/24/2010
according to rules of Annex A
- if TE character set is "HEX": ME/TA converts each 7-bit
character of GSM alphabet into two IRA character
long hexadecimal number (e.g. character P (GSM 23)
is presented as 17 (IRA 49 and 55))
- if <dcs> indicates that 8-bit or UCS2 data coding scheme is
used, or <fo> indicates that GSM 03.40
TP-User-Data-Header-Indication is set: ME/TA
converts each 8-bit octet into two IRA character long
hexadecimal number (e.g. octet with integer value 42
is presented to TE as two characters 2A (IRA 50 and
65)) In the case of CBS: GSM 03.41 CBM Content of
Message in text mode responses; format:
- if <dcs> indicates that GSM 03.38 default alphabet is used:
- if TE character set other than "HEX" (refer Command +CSCS
in GSM 07.07): ME/TA converts GSM alphabet into
current TE character set according to rules of Annex A
- if TE character set is "HEX": ME/TA converts each 7-bit
character of GSM alphabet into two IRA character
long hexadecimal number
- if <dcs> indicates that 8-bit or UCS2 data coding scheme is
used: ME/TA converts each 8-bit octet into two IRA
character long hexadecimal number
<length> integer type value indicating in the text mode (+CMGF=1)
the length of the message body <data> (or <cdata>) in
characters; or in PDU mode (+CMGF=0), the length of the
actual TP data unit in octets (i.e. the RP layer SMSC address
octets are not counted in the length)
<index> integer type; value in the range of location numbers supported
by the associated memory
<oa> GSM 03.40 TP-Originating-Address Address-Value field in
string format; BCD numbers (or GSM default alphabet
characters) are converted to characters of the currently
selected TE character set (refer Command +CSCS in TS
07.07); type of address given by <tooa>
<pdu> In the case of SMS: GSM 04.11 SC address followed by
GSM 03.40 TPDU in hexadecimal format: ME/TA converts
each octet of TP data unit into two IRA character long
hexadecimal number (e.g. octet with integer value 42 is
presented to TE as two characters 2A (IRA 50 and 65)). In
the case of CBS: GSM 03.41 TPDU in hexadecimal format.
<scts> GSM 03.40 TP-Service-Center-Time-Stamp in time-string
format (refer <dt>)
<toda> GSM 04.11 TP-Destination-Address Type-of-Address octet
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 102 12/24/2010
in integer format (when first character of <da> is + (IRA 43)
default is 145, otherwise default is 129)
<tooa> GSM 04.11 TP-Originating-Address Type-of-Address octet in
integer format (default refer<toda>)
1) If text mode:
the same as AT+CMGL="REC UNREAD", received unread messages
2) If PDU mode:
the same as AT+CMGL=0, received unread messages
See more messages please refer to Write Command.
Execution
Command
AT+CMGL
Parameters
See Write Command
Reference
GSM 07.05
Note
4.2.4 AT+CMGR Read SMS Message
AT+CMGR Read SMS Message
Test Command
AT+CMGR=?
Response
OK
Parameters
<index> integer type; value in the range of location numbers supported
by the associated memory
<mode> 0 normal
1 not change status of the specified SMS record
Write Command
AT+CMGR=<in
dex>[,<mode>]
Response
TA returns SMS message with location value <index> from message storage
<mem1> to the TE. If status of the message is 'received unread', status in the
storage changes to 'received read'.
1) If text mode (+CMGF=1) and Command successful:
for SMS-DELIVER:
+CMGR:
<stat>,<oa>,[<alpha>],<scts>[,<tooa>,<fo>,<pid>,<dcs>,<sca>,<tosca>,
<length>]<CR><LF><data>
for SMS-SUBMIT:
+CMGR:
<stat>,<da>,[<alpha>][,<toda>,<fo>,<pid>,<dcs>,[<vp>],<sca>,<tosca>,
<length>]<CR><LF><data>
for SMS-STATUS-REPORTs:
+CMGR: <stat>,<fo>,<mr>,[<ra>],[<tora>],<scts>,<dt>,<st>
for SMS-COMMANDs:
+CMGR:
SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 103 12/24/2010
<stat>,<fo>,<ct>[,<pid>,[<mn>],[<da>],[<toda>],<length><CR><LF><
cdata>]
for CBM storage:
+CMGR: <stat>,<sn>,<mid>,<dcs>,<page>,<pages><CR><LF><data>
2) If PDU mode (+CMGF=0) and Command successful:
+CMGR: <stat>,[<alpha>],<length><CR><LF><pdu>
OK
3) If error is related to ME functionality:
+CMS ERROR: <err>
Parameters
<alpha> string type (string should be included in quotation marks)
alphanumeric representation of <da> or <oa> corresponding
to the entry found in MT phonebook; implementation of this
feature is manufacturer specific
<da> GSM 03.40 TP-Destination-Address Address-Value field in
string format; BCD numbers (or GSM default alphabet
characters) are converted to characters of the currently
selected TE character set (specified by +CSCS in TS 07.07);
type of address given by <toda>
<data> In the case of SMS: GSM 03.40 TP-User-Data in text mode
responses; format:
- if <dcs> indicates that GSM 03.38 default alphabet is used and
<fo> indicates that GSM 03.40
TPUser-Data-Header-Indication is not set:
- if TE character set other than "HEX" (refer Command Select
TE Character Set +CSCS in TS 07.07):ME/TA
converts GSM alphabet into current TE character set
according to rules of Annex A
- if TE character set is "HEX": ME/TA converts each 7-bit
character of GSM alphabet into two IRA character
long hexadecimal number (e.g. character P (GSM 23)
is presented as 17 (IRA 49 and 55))
- if <dcs> indicates that 8-bit or UCS2 data coding scheme is
used, or <fo> indicates that GSM 03.40
TP-User-Data-Header-Indication is set: ME/TA
converts each 8-bit octet into two IRA character long
hexadecimal number (e.g. octet with integer value 42
is presented to TE as two characters 2A (IRA 50 and
65)) In the case of CBS: GSM 03.41 CBM Content of
Message in text mode responses; format:
- if <dcs> indicates that GSM 03.38 default alphabet is used: