This document describes the AT command set for Quectel LTE modules EC200U series, EG800G series, EG91xU family, and EG915G‑EU. It focuses purely on technical content: syntax, parameters, behavior, and examples.

Supported module families:

EC200U series

EG800G series

EG912U series

EG915U series

EG915G‑EU

Note: Preset files in the file system (for GNSS, BT, TTS, etc.) must not be deleted.

AT Command Syntax and Conventions

1.1 Basic notation

AT command lines:

All commands start with the prefix 'AT' or 'at'.

Lines end with a termination character (default: carriage return).

Commands are case‑insensitive.

Result codes:

Final result codes: OK, ERROR, +CME ERROR, +CMS ERROR, etc.

Information responses: additional text or parameter lines between command and final result.

Special symbols:

<name> : Syntactic element or parameter; angle brackets do not appear in actual commands.

[ ... ] : Optional parameter or optional response part; brackets do not appear in commands.

Parameter rules:

Comma (,) separates parameters.

Strings containing spaces or certain characters must be within quotes.

Optional trailing parameters may be omitted; their values remain unchanged or default.

Multiple commands:

Several commands can be issued on one line separated by semicolons, for example:
AT+CSQ;AT+CREG?

Termination:

By default, command lines end with CR. LF may be ignored on input but is used in output formatting.

1.2 Command categories

Basic commands:

Format: ATx or AT&x, where 'x' is the keyword.

Example: ATE0, AT&F.

S‑parameter commands:

Format: ATSn=m

Example: ATS3=13 (set line termination character).

Extended commands:

Have the form AT+<cmd> and support up to four sub‑types:

Types of extended command:

Test command: AT+CMD=?

Returns information about supported parameter formats and ranges.

Read command: AT+CMD?

Reports current settings.

Write command: AT+CMD=<p1>[,<p2>...]

Sets parameter values.

Execute command: AT+CMD

Triggers an action or queries data without parameters.

1.3 Character sets

Character sets are controlled by AT+CSCS. Supported sets include:

"GSM"

"IRA"

"UCS2"

"HEX"

"PCCP936"

The selected character set affects SMS text, cell broadcast text, and phonebook strings.

1.4 Interfaces and URCs

Main interfaces: main UART, auxiliary UARTs, USB modem port, USB AT port.

URCs (unsolicited result codes) indicate events such as:

Incoming calls (RING)

Incoming SMS (+CMTI / +CMT)

Registration status changes (+CREG, +CEREG)

Signal strength changes (+CSQ / +QCSQ URCs if enabled)

URC routing and filtering are controlled mainly by AT+QURCCFG and AT+QINDCFG.

1.5 Recommended power‑off

AT+QPOWD performs a graceful software power‑off:

Logs the module off the network.

Saves internal state.

Outputs a POWERED DOWN indication and pulls STATUS low.

After POWERED DOWN and STATUS low, the host should cut VBAT (recommended delay about 1 second).

If POWERED DOWN is not seen within about 65 seconds, VBAT may be cut forcibly.

General Commands

2.1 ATI – Display module identification

Syntax:

ATI

Description:

Returns manufacturer, model, and firmware revision.

Typical response:

Quectel

EC200U

Revision: EC200UCNAAR01A04M08

OK

2.2 AT+GMI / AT+CGMI – Manufacturer identification

Syntax:

AT+GMI=?

AT+GMI

AT+CGMI=?

AT+CGMI

Description:

Returns manufacturer string, typically "Quectel".

Response:

Quectel

OK

2.3 AT+GMM / AT+CGMM – Model identification

Syntax:

AT+GMM=?

AT+GMM

AT+CGMM=?

AT+CGMM

Description:

Returns module model, e.g. EC200U, EG800G, etc.

2.4 AT+GMR / AT+CGMR – Firmware revision

Syntax:

AT+GMR=?

AT+GMR

AT+CGMR=?

AT+CGMR

Description:

Returns firmware revision string.

2.5 AT+GSN / AT+CGSN – IMEI and serial number

Syntax:

AT+GSN=?

AT+GSN=<snt>

AT+GSN

AT+CGSN=?

AT+CGSN=<snt>

AT+CGSN

Parameters:

<snt> = 0 : Return serial number.

<snt> = 1 : Return IMEI.

Execution without parameter:

Returns IMEI only.

Errors:

+CMS ERROR:<err> if ME‑related error occurs.

2.6 AT&F – Restore factory defaults

Syntax:

AT&F

AT&F<value>

Description:

Restores AT configuration to factory defaults for the selected profile (commonly profile 0).

2.7 AT&V – Show current configuration

Syntax:

AT&V

Description:

Displays many AT settings (E, Q, V, X, S‑registers, etc.) in a human‑readable snapshot.

2.8 AT&W – Store configuration to profile

Syntax:

AT&W

AT&W<n>

Description:

Saves current AT configuration into user profile (usually profile 0).

Many commands note that changes persist only if AT&W is executed.

2.9 ATZ – Restore from user profile

Syntax:

ATZ

ATZ<value>

Description:

Restores settings from a stored profile (commonly profile 0).

2.10 ATQ – Result code echo mode

Syntax:

ATQ<n>

Parameters:

0 : Enable final result codes (OK/ERROR).

1 : Suppress final result codes.

Notes:

Does not affect informational text, only final result codes.

Take care when using 1; debugging is more difficult.

2.11 ATV – Result code format

Syntax:

ATV<value>

Parameters:

0 : Numeric codes only, short format.

1 : Verbose text codes, CR/LF framed.

Example mapping:

0 = OK

1 = CONNECT

2 = RING

3 = NO CARRIER

4 = ERROR

6 = NO DIALTONE

7 = BUSY

8 = NO ANSWER

2.12 ATE – Command echo mode

Syntax:

ATE<value>

Parameters:

0 : Echo OFF.

1 : Echo ON.

2.13 A/ – Repeat previous command line

Syntax:

A/

Description:

Repeats the last executed AT command line exactly.

Does not require the "AT" prefix.

2.14 ATS3 – Command line termination character

Syntax:

ATS3?

ATS3=<n>

Range:

0–127, default 13 (CR).

2.15 ATS4 – Response formatting character

Syntax:

ATS4?

ATS4=<n>

Range:

0–127, default 10 (LF).

2.16 ATS5 – Command line editing character

Syntax:

ATS5?

ATS5=<n>

Range:

0–127, default 8 (backspace).

2.17 ATX – Result code and call progress behavior

Syntax:

ATX<value>

Values:

0 to 4 (increasing call progress detail and tone detection).

Higher values typically enable CONNECT <text> and dial‑tone/busy detection.

2.18 AT+CFUN – Function mode

Syntax:

AT+CFUN=?

AT+CFUN?

AT+CFUN=<fun>[,<rst>]

Parameters:

<fun>:

0 : Minimum functionality (RF and some subsystems may be off).

1 : Full functionality.

4 : RF off (airplane mode).

<rst> (only meaningful when <fun>=1):

0 : No reset.

1 : Reset before entering full functionality.

Description:

Controls power level and RF state of the module.

2.19 AT+CMEE – Error message format

Syntax:

AT+CMEE=?

AT+CMEE?

AT+CMEE=<n>

Parameters:

0 : Disable +CME ERROR; use generic ERROR.

1 : Numeric +CME ERROR codes.

2 : Text +CME ERROR descriptions.

Recommendation:

Use 2 during development.

2.20 AT+CSCS – Select TE character set

Syntax:

AT+CSCS=?

AT+CSCS?

AT+CSCS=<chset>

Supported <chset>:

"GSM", "HEX", "PCCP936", "IRA", "UCS2"

2.21 AT+QURCCFG – URC output routing

Syntax:

AT+QURCCFG=?

AT+QURCCFG="urcport"

AT+QURCCFG="urcport",<urc_port_value>

<urc_port_value>:

"usbat" : USB AT port

"usbmodem": USB modem port

"uart1" : main UART

"uart2" : UART2

"uart3" : UART3

"usbnmea" : specific USB serial

"all" : send URCs to all ports

UART Control Commands

3.1 AT&C – DCD function mode

Syntax:

AT&C[<value>]

Parameters:

0 : DCD always ON.

1 : DCD ON only when carrier is present.

3.2 AT&D – DTR function mode

Syntax:

AT&D[<value>]

Parameters:

0 : Ignore DTR.

1 : Transition low→high causes return to command mode, keeping call.

2 : Transition low→high causes call drop and return to command mode.

3.3 AT+IFC – UART flow control

Syntax:

AT+IFC=?

AT+IFC?

AT+IFC=<dce_by_dte>,<dte_by_dce>

Values:

0 : No flow control.

2 : RTS/CTS hardware flow control.

Typical:

AT+IFC=2,2 for full RTS/CTS.

3.4 AT+ICF – UART frame format and parity

Syntax:

AT+ICF=?

AT+ICF?

AT+ICF=[<format>[,<parity>]]

Formats:

1 : 8N2

2 : 8E1 or 8O1 (depending on parity)

3 : 8N1

Parity (for format=2):

0 : odd

1 : even

3.5 AT+IPR – UART fixed baud rate

Syntax:

AT+IPR=?

AT+IPR?

AT+IPR=<rate>

Parameters:

0 : Autobaud (adaptive).

Fixed rates: module supports a set of discrete baud rates (e.g. 1200–2 Mbit/s; exact list given in original manual).

Notes:

Host must match the configured baud.

Not changeable while in CMUX mode.

3.6 AT+CBAUD – Configure main UART baud

Syntax:

AT+CBAUD=?

AT+CBAUD?

AT+CBAUD=<rate>

Description:

Similar to AT+IPR but explicitly for main UART; rates are module‑specific.

3.7 AT+QIPR – UART2/UART3 baud rate

Syntax:

AT+QIPR=?

AT+QIPR?

AT+QIPR=<port>,<rate>

Ports:

1 : UART2

2 : UART3

3.8 AT+QICF – UART2/UART3 frame format and parity

Syntax:

AT+QICF=?

AT+QICF?

AT+QICF=<port>,<format>[,<parity>]

Parameters: same meaning as AT+ICF, with <port> specifying UART2 or UART3.

3.9 AT+QIFC – UART2/UART3 flow control

Syntax:

AT+QIFC=?

AT+QIFC?

AT+QIFC=<port>[,<dce_by_dte>,<dte_by_dce>]

Status Control and Extended Settings

4.1 AT+CPAS – Equipment activity status

Syntax:

AT+CPAS=?

AT+CPAS

Responses:

+CPAS:<pas>

<pas>:

0 : Ready

2 : Unknown

3 : Ringing

4 : Call in progress or on hold

Note:

Not supported on some data‑only modules.

4.2 AT+CEER – Extended error report

Syntax:

AT+CEER=?

AT+CEER?

AT+CEER=<mode>

AT+CEER

<mode> examples:

0 : +CEER:<locationID>,<causeID>

1 : +CEER:<locationID>,<causeText> or +CEER:<category>,<locationID>,<causeText>

Description:

Gives extended reason for last failed procedure (call setup, attach, etc.).

4.3 AT+QINDCFG – URC indication configuration

Syntax:

AT+QINDCFG=?

AT+QINDCFG=<URC_type>[,<enable>[,<save_to_nvram>]]

Key <URC_type> values:

"all" : master switch for URCs.

"csq" : signal strength change.

"act" : RAT/AcT change (GSM/EGPRS/WCDMA/LTE/…).

"smsincoming" : SMS URCs (+CMT, +CMTI, +CDS).

"ring" : RING URCs.

"psm" : PSM entry/exit.

"rach" : random access channel result.

others as listed in the original list.

<enable>:

0 : disabled.

1 : enabled.

<save_to_nvram>:

0 : do not save.

1 : save configuration.

4.4 AT+QRDY – Initialization status

Syntax:

AT+QRDY

Description:

Returns a URC indicating module is ready after boot.

May be used by host to know when to start configuration.

4.5 AT+QCFG – Extended settings group

QCFG is a container for many sub‑settings:

General syntax:

AT+QCFG="name"

AT+QCFG="name",<...>

AT+QCFG="name"=?

Important sub‑commands:

4.5.1 QCFG "nwscanmode" – Network search mode

Syntax:

AT+QCFG="nwscanmode"

AT+QCFG="nwscanmode",<mode>

<mode>:

Values select automatic, LTE‑only, GSM‑only, etc. (module‑dependent mapping).

4.5.2 QCFG "band" – Search bands

Syntax:

AT+QCFG="band"

AT+QCFG="band",<gsm_mask>,<lte_mask>

Description:

Restricts which GSM/LTE bands can be used.

4.5.3 QCFG "creg/emergency" – Emergency network display

Controls how emergency registration info is indicated in +CREG.

4.5.4 QCFG "qoos" – Out‑of‑service search timers

Settings for how often the module searches when out of service.

4.5.5 QCFG "airplanecontrol" – Airplane mode control

Controls behavior of airplane (RF off) mode in conjunction with AT+CFUN and possibly GPIO pins.

4.5.6 QCFG "usbnet" – USB network protocol

Chooses ECM/RNDIS/NCM etc. for USB data interface.

4.5.7 QCFG "nat/cid" and "nat/subnet" – NAT settings

Enable NAT for PDP context and configure subnet parameters for NAT.

4.5.8 QCFG "usbnetmac" – USB network MAC address

Allows configuring the MAC address used on USB network adapter.

4.5.9 QCFG "apready" – AP_Ready pin behavior

Controls the logic of the AP_READY pin handshake with host.

4.5.10 QCFG "pkalive/ip" – PDP keepalive

Configures keepalive for IP PDN contexts.

4.5.11 QCFG "ledmode" and "led/sim" – Status LED behavior

Configures network status LED patterns and which SIM is indicated in dual‑SIM setups.

4.5.12 QCFG "tone/incoming" – Incoming call ringtone

Types and patterns for ringing output.

4.5.13 QCFG "sleepind/level" and "wakeupin/level" – Sleep/wake pins

Configures signal levels and behaviors for sleep indication and wakeup pin.

4.5.14 QCFG "ntp" – NTP retransmission count and interval

For modules using NTP functions; configures retries and intervals.

4.5.15 QCFG "esmfail/times" – LTE registration failure threshold

Number of consecutive LTE registration failures before falling back to GSM.

4.5.16 QCFG "rtc/cfg" – RTC startup configuration

Behavior of RTC at boot.

4.5.17 QCFG "pdn/pco" – PDN PCO behavior

Whether PDN requests carry certain PCO fields.

(Other QCFG sub‑commands follow the same pattern: simple name, one or more integer/enum parameters, and persistent configuration.)

(U)SIM Related Commands

5.1 AT+CIMI – Read IMSI

Syntax:

AT+CIMI

Response:

<IMSI>
OK

5.2 AT+CLCK – Facility lock

Syntax:

AT+CLCK="fac",<mode>[,"password"[,<class>]]

Used for SIM locks (PIN locks, call barring, etc.), not always needed in basic data use.

5.3 AT+CPIN – Enter PIN

Syntax:

AT+CPIN=?

AT+CPIN?

AT+CPIN="<pin>"

Response examples:

+CPIN: READY

+CPIN: SIM PIN

+CPIN: SIM PUK

5.4 AT+CPWD – Change password

Syntax:

AT+CPWD="fac","old","new"

5.5 AT+CSIM – Generic SIM access

Raw APDU interface; used for advanced SIM operations.

5.6 AT+CRSM – Restricted SIM access

More structured SIM access (e.g. READ BINARY, UPDATE RECORD).

5.7 AT+QCCID – Show ICCID

Syntax:

AT+QCCID

Response:

+QCCID:<iccid>

OK

5.8 AT+QINISTAT – SIM initialization status

Syntax:

AT+QINISTAT

Reports whether SIM initialization is in progress or complete.

5.9 AT+QSIMDET – SIM detection

Configures card detect behavior; optional for designs that want SIM hot‑swap detection.

5.10 AT+QSIMSTAT – SIM insertion status URC

URC form:

+QSIMSTAT:<slot>,<state>

<state> = 0: not inserted, 1: inserted.

5.11 AT+CCHO / AT+CGLA / AT+CCHC – Logical channel control

Used for UICC logical channels (advanced SIM applications).

5.12 AT+QPINC – Remaining PIN/PUK retries

Syntax:

AT+QPINC

Response lines:

+QPINC:"SC",<retries>

+QPINC:"PUK",<retries>

etc.

Network Service Commands

6.1 AT+COPS – Operator selection

Syntax:

AT+COPS=?

AT+COPS?

AT+COPS=<mode>[,<format>[,<oper>[,<AcT>]]]

6.2 AT+CREG / AT+CGREG / AT+CEREG – Registration status

AT+CREG : CS domain

AT+CGREG: PS domain (GPRS)

AT+CEREG: EPS/LTE

Syntax (example for CEREG):

AT+CEREG=?

AT+CEREG?

AT+CEREG=<n>

<n> = 0/1/2 for URC control.

6.3 AT+CSQ – Basic signal quality

Syntax:

AT+CSQ

Response:

+CSQ:<rssi>,<ber>

6.4 AT+QCSQ – Detailed signal

Syntax:

AT+QCSQ

Response includes RAT and metrics such as RSRP, RSRQ, SNR for LTE.

6.5 AT+CPOL – Preferred operator list

Manages stored preferred PLMN list.

6.6 AT+COPN – Operator names

Lists known operator names and codes.

6.7 AT+CTZU – Automatic time zone update

Controls whether time zone is updated from network.

6.8 AT+CTZR – Time zone reporting

Controls URC when time zone changes.

6.9 AT+QLTS – Network time

Syntax:

AT+QLTS[=<mode>]

Response:

+QLTS:"YYYY/MM/DD,HH:MM:SS±TZ",<dst>

6.10 AT+QNWINFO – Network info

Syntax:

AT+QNWINFO

Example:

+QNWINFO:"FDD LTE","46001","LTE BAND 3",1850

6.11 AT+QSPN – Operator name

Returns service provider name.

6.12 AT+CIND – Indicator state

Reports phone‑related indicators (e.g., service, signal, etc.).

Call-Related Commands

7.1 ATA – Answer call

Syntax:

ATA

7.2 ATD – Dial a number

Syntax:

ATD<string>[;<mgsm>]

Dial string: digits, *, #, +, A–C.

Modifiers: I/i for CLIR, G/g for CUG, ';' for voice, etc.

7.3 ATH – Disconnect

Syntax:

ATH

7.4 AT+CVHU – Voice hang up control

Controls whether ATH affects voice calls.

7.5 AT+CHUP – Hang up voice call

Syntax:

AT+CHUP

7.6 "+++" – Escape from data mode

Timing:

Guard times around the +++ sequence (no data for about 1 second before and after).

7.7 ATO – Return to data mode

Syntax:

ATO

7.8 ATS0 – Auto‑answer rings

Syntax:

ATS0?

ATS0=<n>

n = 0 disables auto‑answer; otherwise number of RINGs.

7.9 ATS7 – Connection timeout

Syntax:

ATS7?

ATS7=<n>

n in seconds, 0 disables.

7.10 AT+CSTA – Type of address

Syntax:

AT+CSTA=?

AT+CSTA?

AT+CSTA=<type>

type typical values: 129, 145, 161.

7.11 AT+CLCC – List current calls

Returns all active/held/waiting calls with indexes, directions, statuses.

7.12 AT+CRC – Extended incoming call indication

Enables extended RING indications.

7.13 AT+QECCNUM – Emergency call numbers

Configures emergency numbers in the module.

7.14 AT+QHUP – Hang up with specific cause

Allows setting explicit release cause when hanging up.

7.15 AT+QCHLDIPMPTY – VoLTE conference hang‑up

Used in VoLTE conference calling context.

Phonebook Commands

8.1 AT+CNUM – Subscriber number

Returns own number(s) if available.

8.2 AT+CPBF – Find entries

Syntax:

AT+CPBF="<findtext>"

Finds phonebook entries matching the substring.

8.3 AT+CPBR – Read entries

Syntax:

AT+CPBR=<index1>[,<index2>]

8.4 AT+CPBS – Select storage

Syntax:

AT+CPBS="<storage>"

8.5 AT+CPBW – Write entry

Syntax:

AT+CPBW=<index>,"<number>",<type>,"<text>"

SMS Commands

9.1 AT+CSMS – Select message service

Typically set to 1.

9.2 AT+CMGF – Message format

Syntax:

AT+CMGF=?

AT+CMGF?

AT+CMGF=<mode>

<mode>=0: PDU; <mode>=1: text.

9.3 AT+CSCA – Service center address

Syntax:

AT+CSCA?

AT+CSCA="<sca>"[,<tosca>]

9.4 AT+CPMS – Preferred message storage

Syntax:

AT+CPMS="mem1","mem2","mem3"

9.5 AT+CMGD – Delete message

Syntax:

AT+CMGD=<index>[,<delflag>]

9.6 AT+CMGL – List messages

Syntax:

AT+CMGL="<stat>"

9.7 AT+CMGR – Read message

Syntax:

AT+CMGR=<index>

9.8 AT+CMGS – Send message

Syntax (text mode):

AT+CMGS="<da>"

'>' prompt, then message text, then CTRL+Z.

9.9 AT+CMMS – More messages to send

Controls multi‑message sending behavior.

9.10 AT+CMGW – Write to storage

Writes an SMS to storage for later sending.

9.11 AT+CMSS – Send from storage

Syntax:

AT+CMSS=<index>[,"<da>"[,<tosca>]]

9.12 AT+CNMA – New message acknowledgment

Used for network side requiring explicit ACK.

9.13 AT+CNMI – SMS event reporting

Syntax:

AT+CNMI=?

AT+CNMI?

AT+CNMI=<mode>,<mt>,<bm>,<ds>,<bfr>

Common setting:

AT+CNMI=2,1,0,0,0 (URCs +CMTI with storage).

9.14 AT+CSDH – Show text mode parameters

Controls whether extra text mode fields are displayed.

9.15 AT+CSMP – Set text mode parameters

Controls PID, DCS, validity period, etc.

9.16 AT+QCMGS / AT+QCMGR – Concatenated SMS

Extensions:

AT+QCMGS to send long messages.

AT+QCMGR to read and reassemble long messages.

Packet Domain Commands

10.1 AT+CGATT – Attach/detach PS

Syntax:

AT+CGATT?

AT+CGATT=<state>

<state>:

0: detach, 1: attach.

10.2 AT+CGDCONT – Define PDP context

Syntax:

AT+CGDCONT=?

AT+CGDCONT?

AT+CGDCONT=<cid>,"<PDP_type>","<APN>"[,optional parameters]

PDP_type:

"IP", "IPV6", "IPV4V6", etc.

10.3 AT+CGQREQ / AT+CGQMIN – QoS profile

Set requested and minimum QoS profiles.

10.4 AT+CGACT – Activate/deactivate PDP context

Syntax:

AT+CGACT?

AT+CGACT=<state>,<cid>

10.5 AT+CGDATA – Enter data state

For CSD/packet data; used in some dial‑up scenarios.

10.6 AT+CGPADDR – Show PDP address

Syntax:

AT+CGPADDR[=<cid>]

10.7 AT+CGCLASS – GPRS mobile station class

Configures class (A/B/C) if applicable.

10.8 AT+CGREG – PS domain registration status

Similar to CREG, but PS‑domain specific.

10.9 AT+CGEREP – Packet domain event reporting

Controls URCs for PDP events.

10.10 AT+CGSMS – Select service for MO SMS

Selects whether SMS uses CS or PS domain under certain conditions.

10.11 AT+CEREG – EPS network registration

As described earlier; LTE/EPS registration.

10.12 AT+QGDCNT / AT+QAUGDCNT – Packet data counter

QGDCNT: query data counter.

QAUGDCNT: configure auto‑save of counters.

10.13 AT+CGCONTRDP – Read dynamic PDN parameters

Returns PDN parameters: DNS, gateway, etc.

10.14 AT+QNETDEVCTL – Configure network adapter data call

Associates PDP context with network interface on host (USB network adapters, etc.).

Supplementary Service Commands

11.1 AT+CCFC – Call forwarding

11.2 AT+CCWA – Call waiting

11.3 AT+CHLD – Call related supplementary services

11.4 AT+CLIP – Calling line identification presentation

11.5 AT+CLIR – Calling line identification restriction

11.6 AT+COLP – Connected line presentation

11.7 AT+CSSN – Supplementary service notifications

11.8 AT+CUSD – Unstructured Supplementary Service Data (USSD)

Syntax:

AT+CUSD=<n>[,"<str>"[,<dcs>]]

Audio Commands

12.1 AT+CLVL – Loudspeaker volume

12.2 AT+QAUDLOOP – Audio loop test

12.3 AT+QAUDRD – Record audio file

12.4 AT+QPSND – Play audio to uplink/downlink

12.5 AT+QAUDPLAY – Play audio file

12.6 AT+QAUDSTOP – Stop playing

12.7 AT+QAUDMOD – Audio mode

12.8 AT+QIIC – I2C read/write (audio related)

12.9 AT+QDAI – Digital audio configuration

12.10 AT+QAUDSW – Codec switch

12.11 AT+QAUDPASW – Audio PA type switch

12.12 AT+QTTS – Play text (TTS)

12.13 AT+QWTTS – Play/send text to far end

12.14 AT+QTTSETUP – TTS parameters

12.15 AT+QAUDCFG="urc" – Audio sample rate URC

12.16 AT+QICMIC – Microphone gain

12.17 AT+QRXGAIN – Downlink gain

12.18 AT+QICSIDET – Sidetone gain

12.19 AT+QLDTMF – Local DTMF tone

12.20 AT+QWDTMF – DTMF to far end

12.21 AT+VTS – DTMF send

12.22 AT+QLTONE / AT+QLTONEX – Local custom tones

12.23 AT+QTONEDET – Enable/disable DTMF detection

Hardware Related Commands

13.1 AT+QPOWD – Power off module

Described earlier; graceful shutdown.

13.2 AT+CCLK – Clock

Get/set real‑time clock.

13.3 AT+CBC – Battery charge

Reports battery level and charging state if supported.

13.4 AT+QADC – ADC value

Read analog inputs.

13.5 AT+QWIFISCAN / AT+QWIFISCANEX – Wi‑Fi scan

Synchronous and asynchronous scanning of Wi‑Fi APs by the module (if Wi‑Fi support is present).

Appendices (Conceptual, No Boilerplate)

14.1 CME ERROR codes summary

+CME ERROR:<err> indicates ME specific errors.

14.2 CMS ERROR codes summary

+CMS ERROR:<err> indicates SMS subsystem errors.

14.3 URC summary

List of all URCs used by this firmware, such as:

RING, NO CARRIER, +CMTI, +CMT, +CREG, +CEREG, +QIND:..., +QSIMSTAT:..., +QNWINFO, etc.

14.4 SMS character set conversion tables

Logical mapping between GSM 7‑bit, IRA, UCS2, etc.

Important only for low‑level SMS encoding/decoding.

14.5 Release cause text for AT+CEER

Mapping of location IDs and cause IDs to descriptive text.

End of cleaned Quectel EC200U / EG800G / EG91xU / EG915G‑EU AT Commands text.