Name: SIM900 AT Command Manual V1.03
SIM900_AT_Command_Manual_V1.03
SIM900_AT_Command_Manual_V1.03
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SIM900_AT%20Command%20Manual_V1.03
SIM900_AT%20Command%20Manual_V1.03
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SIM900_AT Manual_ V1.03 Command SIM900 AT Command Manual 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_V1.03 2 12/24/2010 SIM900 AT Command Manual 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_V1.03 3 12/24/2010 SIM900 AT Command Manual 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>Originate Call to Phone Number in Current Memory................................20 2.2.5 ATD> Originate Call to Phone Number in Memory Which Corresponds to Field ........................................................................................................................................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_V1.03 4 12/24/2010 SIM900 AT Command Manual 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_V1.03 5 12/24/2010 SIM900 AT Command Manual 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_V1.03 6 12/24/2010 SIM900 AT Command Manual 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_V1.03 7 12/24/2010 SIM900 AT Command Manual 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_V1.03 8 12/24/2010 SIM900 AT Command Manual 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_V1.03 9 12/24/2010 SIM900 AT Command Manual 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_V1.03 10 12/24/2010 SIM900 AT Command Manual 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_V1.03 11 12/24/2010 SIM900 AT Command Manual 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 . Commands are usually followed by a response that includes. " " Throughout this document, only the responses are presented, 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 ", or "AT& ", where " "is the Command, and " "is/are the argument(s) for that Command. An example of this is "ATE ", which tells the DCE whether received characters should be echoed back to the DTE according to the value of " ". " " is optional and a default will be used if missing. SIM900_AT Command Manual_V1.03 12 12/24/2010 SIM900 AT Command Manual 1.4.2 S Parameter syntax These AT commands have the format of "ATS = ", where " " is the index of the S register to set, and " "is the value to assign to it. " " 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+ =? The mobile equipment returns the list of parameters and value ranges set with the corresponding Write Command or by internal processes. Read Command AT+ ? This command returns the currently set value of the parameter or parameters. Write Command AT+ =<…> This command sets the user-definable parameter values. Execution Command AT+ 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_V1.03 13 12/24/2010 SIM900 AT Command Manual • 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_V1.03 14 12/24/2010 SIM900 AT Command Manual 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_V1.03 15 12/24/2010 SIM900 AT Command Manual 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> ORIGINATE CALL TO PHONE NUMBER IN CURRENT MEMORY ATD> ORIGINATE CALL TO PHONE NUMBER IN MEMORY WHICH CORRESPONDS TO FIELD ATDL 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 ATS0 SET NUMBER OF RINGS ANSWERING THE CALL ATS3 SET COMMAND LINE TERMINATION CHARACTER ATS4 SET RESPONSE FORMATTING CHARACTER ATS5 SET COMMAND LINE EDITING CHARACTER ATS6 PAUSE BEFORE BLIND DIALLING ATS7 SET NUMBER OF SECONDS TO WAIT FOR CONNECTION COMPLETION ATS8 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_V1.03 16 BEFORE AUTOMATICALLY 12/24/2010 SIM900 AT Command Manual 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+GCAP REQUEST COMPLETE TA CAPABILITIES LIST AT+GMI REQUEST MANUFACTURER IDENTIFICATION AT+GMM REQUEST TA MODEL IDENTIFICATION AT+GMR REQUEST TA REVISION RELEASE AT+GOI REQUEST GLOBAL OBJECT IDENTIFICATION AT+GSN REQUEST TA SERIAL NUMBER IDENTIFICATION (IMEI) AT+ICF SET TE-TA CONTROL CHARACTER FRAMING AT+IFC SET TE-TA LOCAL DATA FLOW CONTROL AT+IPR SET TE-TA FIXED LOCAL RATE AT+HVOIC DISCONNECT VOICE CALL ONLY IDENTIFICATION OF SOFTWARE 2.2 Detailed Description of AT Commands According to V.25TER 2.2.1 A/ A/ Re-issues the Last Command Given 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_V1.03 17 12/24/2010 SIM900 AT Command Manual 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 TA switches to data mode. Note: output only if ATX parameter setting with the >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 2.2.3 ATD ATD Note See also ATX Mobile Originated Call to Dial A Number Mobile Originated Call to Dial A Number Execution Command ATD [ TA switches to data mode. Note: output only if ATX parameter setting with the >0 When TA returns to Command mode after call release OK If connection successful and voice call OK Parameters 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: Standardized emergency number 112 (no SIM needed) 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 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_V1.03 19 12/24/2010 SIM900 AT Command Manual 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> ATD> Originate Call to Phone Number in Current Memory Originate Call to Phone Number in Current Memory Execution Command ATD> [ ][ ][;] 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: 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 TA switches to data mode. Note: output only if ATX parameter setting with the >0 When TA returns to Command mode after call release OK If successfully connected and voice call SIM900_AT Command Manual_V1.03 20 12/24/2010 SIM900 AT Command Manual OK Parameters Integer type memory location should be in the range of locations available in the memory used String of GSM modifiers: I i Override the CLIR supplementary service subscription default value for this call Invocation (restrict CLI presentation) Override the CLIR supplementary service subscription default value for this call Suppression (allow CLI presentation) 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 G <;> 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> ATD> Originate Call to Phone Number in Memory Which Corresponds to Field Originate Call to Phone Number in Memory Which Corresponds to Field Execution Command ATD> [ ][ ][;] Response This Command make the TA attempts to set up an outgoing call to stored number. All available memories are searched for the entry . 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: If no dial tone and (parameter setting ATX2 or ATX4) SIM900_AT Command Manual_V1.03 21 12/24/2010 SIM900 AT Command Manual 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 TA switches to data mode. Note: output only if ATX parameter setting with the >0 When TA returns to Command mode after call release OK If successfully connected and voice call OK Parameters <;> Reference V.25ter 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. 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 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_V1.03 22 12/24/2010 SIM900 AT Command Manual 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: 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 TA switches to data mode. Note: output only if ATX parameter setting with the >0 When TA returns to Command mode after call release OK If successfully connected and voice call OK Reference V.25ter 2.2.7 ATE ATE 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. Set Command Echo Mode Set Command Echo Mode Execution Response SIM900_AT Command Manual_V1.03 23 12/24/2010 SIM900 AT Command Manual Command ATE This setting determines whether or not the TA echoes characters received from TE during Command state. OK Parameter Reference V.25ter 2.2.8 ATH ATH 0 Echo mode off 1 Echo mode on Note Disconnect Existing Connection Disconnect Existing Connection Execution Command ATH[n] 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. Parameter 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_V1.03 24 12/24/2010 SIM900 AT Command Manual 2.2.9 ATI ATI Display Product Identification Information 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 Execution Command ATL Reference V.25ter Response OK Parameter 0..9 volume Note No effect in GSM 2.2.11 ATM Set Monitor Speaker Mode ATM Set Monitor Speaker Mode Execution Command ATM Reference V.25ter Response OK Parameter 0..9 mode 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_V1.03 25 12/24/2010 SIM900 AT Command Manual 1. 2. 3. 4. No characters entered for T1 time (1 second) "+++" characters entered with no characters in between (0.5 second) No characters entered for T1 timer (0.5 second) 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 Execution Command ATO[n] 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 Note: only if parameter setting ATX>0 Parameter 0 Reference V.25ter Switch from Command mode to data mode. 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 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_V1.03 26 12/24/2010 SIM900 AT Command Manual If =0: OK If =1: (none) Parameter 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 Read Command ATS0? Response OK Parameter See Write Command Write Command ATS0= Response This parameter setting determines the number of rings before auto-answer. OK ERROR Parameter 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 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 Read Command ATS3? Response OK Parameter See Write Command Write Command ATS3= Response This parameter setting determines the character recognized by TA to SIM900_AT Command Manual_V1.03 27 12/24/2010 SIM900 AT Command Manual terminate an incoming Command line. The TA also returns this character in output. OK ERROR Parameter 13 Command line termination character Reference V.25ter 2.2.18 ATS4 ATS4 Note Default 13 = CR. It only supports default value. Set Response Formatting Character Set Response Formatting Character Read Command ATS4? Response OK Parameter See Write Command Write Command ATS4= Response This parameter setting determines the character generated by the TA for result code and information text. OK ERROR Parameter 10 Response formatting character Reference V.25ter 2.2.19 ATS5 ATS5 Note Default 10 = LF. It only supports default value. Set Command Line Editing Character Set Command Line Editing Character Read Command ATS5? Response OK Parameter See Write Command Write Command ATS5= 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_V1.03 28 12/24/2010 SIM900 AT Command Manual character. OK ERROR Parameter 0-8-127 Reference V.25ter 2.2.20 ATS6 ATS6 Response formatting character Note Default 8 = Backspace. Pause Before Blind Dialling Pause Before Blind Dialling Read Command ATS6? Response ERROR Write Command ATS6= Response OK ERROR Parameter 0..999 Reference V.25ter Time 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 Read Command ATS7? Response OK Parameter See Write Command Write Command ATS7= 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 Parameter 1-60-255 Reference Number of seconds to wait for connection completion Note SIM900_AT Command Manual_V1.03 29 12/24/2010 SIM900 AT Command Manual z V.25ter z z z If called party has specified a high value for ATS0= , call setup may fail. The correlation between ATS7 and ATS0 is important Example: Call may fail if ATS7=30 and ATS0=20. 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 Read Command ATS8? Response OK Parameter See Write Command Write Command ATS8= Response OK ERROR Parameter 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 2.2.23 ATS10 ATS10 Note No effect in GSM Set Disconnect Delay after Indicating the Absence of Data Carrier Set Disconnect Delay after Indicating the Absence of Data Carrier Read Command ATS10? Response OK Parameter See Write Command Write Command ATS10= 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 Parameter SIM900_AT Command Manual_V1.03 30 12/24/2010 SIM900 AT Command Manual Reference V.25ter 1-15-254 Number of tenths seconds of delay 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 Execution Command ATV Response This parameter setting determines the contents of the header and trailer transmitted with result codes and information responses. When =0 0 When =1 OK Parameter Information response: Short result code format: 1 Information response: Long result code format: The result codes, their numeric equivalents and brief descriptions of the use of each are listed in the following table. Reference V.25ter 0 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_V1.03 31 12/24/2010 SIM900 AT Command Manual 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 Manufacturerspecific 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 ATX Set CONNECT Result Code Format and Monitor Call Progress Set CONNECT Result Code Format and Monitor Call Progress Execution Command ATX 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 Parameter 0 1 2 3 4 Reference V.25ter 2.2.27 ATZ CONNECT result code only returned, dial tone and busy detection are both disabled. CONNECT result code only returned, dial tone and busy detection are both disabled. CONNECT result code returned, dial tone detection is enabled, busy detection is disabled. CONNECT result code returned, dial tone detection is disabled, busy detection is enabled. CONNECT result code returned, dial tone and busy detection are both enabled. Note Reset Default Configuration ATZ Reset Default Configuration Execution Command ATZ[ ] Response TA sets all current parameters to the user defined profile. OK SIM900_AT Command Manual_V1.03 32 12/24/2010 SIM900 AT Command Manual ERROR Parameter Reference V.25ter 0 Restore profile 0 1 Restore profile 1 Note Parameter impacted by Z command: Command Parameter name Default value ATE 0x01 ATQ 0x00 ATV 0x01 ATX 0x04 AT&C 0x01 AT&D 0x01 AT+IFC 0x00 AT+IFC 0x00 AT+FCLASS 0x00 ATS0 0x00 ATS3 0x00 ATS4 0x0D ATS5 0x0A ATS7