TRM240 AT Commands

Quectel EC21 AT command list

Basic / General Commands

Command	Description
AT	Test communication with the module
ATI	Display product identification information
AT+CGMI	Request manufacturer identification
AT+CGMM	Request model identification
AT+CGMR	Request software revision identification
AT+GMI	Request manufacturer identification
AT+GMM	Request model identification
AT+GMR	Request software revision identification
AT+GSN	Request product serial number (IMEI)
AT+QGMR	Query detailed firmware version information
ATZ	Restore stored profile
AT&F	Restore factory default settings
AT&W	Save current configuration profile
AT&V	Display active and stored profiles
ATE0 / ATE1	Disable / Enable command echo
AT+CMEE=2	Enable verbose CME error reporting
AT+CLAC	List supported AT commands

SIM Card

Command	Description
AT+CIMI	Request International Mobile Subscriber Identity (IMSI)
AT+QCCID	Show ICCID of the SIM card
AT+CPIN?	Query SIM PIN status
AT+CPIN="1234"	Enter SIM PIN
AT+CLCK="SC",2	Query SIM lock status
AT+QPINC?	Display remaining PIN/PUK retry counters
AT+QINISTAT	Query initialization status of the SIM card
AT+QSIMDET?	Query SIM card detection configuration
AT+QSIMSTAT?	Query SIM card insertion status

Network Registration & Status

Command	Description
AT+CREG?	Query circuit-switched network registration status
AT+CGREG?	Query GPRS network registration status
AT+CEREG?	Query EPS/LTE network registration status
AT+COPS?	Query selected network operator
AT+COPS=?	Search available network operators
AT+COPS=0	Select operator automatically
AT+COPS=1,2,"26001"	Select operator manually using MCC/MNC
AT+CSQ	Report received signal strength indication and channel bit error rate
AT+QCSQ	Query current radio signal quality
AT+QNWINFO	Query access technology, operator and selected band
AT+QENG="servingcell"	Query serving cell information
AT+QENG="neighbourcell"	Query neighboring cell information
AT+CPAS	Query mobile equipment activity status

APN & PDP Context (Data Connection)

Command	Description
AT+CGDCONT?	Query defined PDP contexts
AT+CGDCONT=1,"IP","your.apn"	Define PDP context
AT+CGACT?	Query PDP context activation state
AT+CGACT=1,1	Activate PDP context
AT+CGACT=0,1	Deactivate PDP context
AT+CGPADDR=1	Show PDP address assigned to a context
AT+CGCONTRDP=1	Read dynamic PDP context parameters
AT+QICSGP=1,1,"apn","user","pass",1	Configure APN and authentication parameters
AT+QIACT=1	Activate wireless connection
AT+QIDEACT=1	Deactivate wireless connection
AT+QIACT?	Query activated connection information

Network Mode & Band Selection

Command	Description
AT+CFUN?	Query functionality level
AT+CFUN=0	Set minimum functionality mode
AT+CFUN=1	Set full functionality mode
AT+CFUN=4	Disable RF functionality
AT+CFUN=1,1	Reset the module
AT+QCFG="nwscanmode"	Configure network scan mode
AT+QCFG="nwscanseq"	Configure network scan sequence
AT+QCFG="band"	Configure supported frequency bands
AT+QCFG="roamservice"	Configure roaming service
AT+QCFG="servicedomain"	Configure service domain

SMS

Command	Description
AT+CMGF=1	Select SMS text mode
AT+CMGS="+37060000000"	Send SMS message (Crtl + Z in terminal to send)
AT+CMGL="ALL"	List stored SMS messages
AT+CMGR=1	Read SMS message from storage
AT+CMGD=1	Delete SMS message from storage
AT+CNMI=2,1	Configure new SMS indications

Voice Calls

Command	Description
ATD+37060000000;	Originate a voice call
ATA	Answer an incoming call
ATH	Disconnect a call
AT+CHUP	Release ongoing call
AT+CLCC	List current calls
AT+CLIP=1	Enable calling line identification presentation

Serial / Interface

Command	Description
AT+IPR?	Query UART baud rate
AT+IPR=115200	Set UART baud rate
AT+IFC=2,2	Enable RTS/CTS hardware flow control
AT+CMUX=0	Enable GSM multiplexing protocol
AT+QURCCFG	Configure unsolicited result code output port

Diagnostics & Debugging

Command	Description
AT+CEER	Report extended error information
AT+CGCONTRDP=1	Display dynamic PDP context parameters
AT+QNWINFO	Query current network information
AT+QENG="servingcell"	Display serving cell measurements and parameters
AT+QENG="neighbourcell"	Display neighboring cell measurements
AT+QCSQ	Display current signal quality information
AT+QCAINFO	Query carrier aggregation information
AT+QCFG="dbgctl"	Configure debug information output

Note: This document covers only the essential AT commands supported by the device. For the full AT command reference, please contact Quectel directly.