AT Command Handbook
Last revision 2025/12/31
The AT Command Handbook serves as a detailed guide on AT commands for querying device details, managing SIM cards, and setting up MQTT connections, vital for optimizing module performance.
Common AT Commands
| Command | Meaning | Return Value |
|---|---|---|
| AT | AT test command | OK |
| AT+CGMI | Query manufacturer name | OK |
| AT+CGMM | Query module model | OK |
| AT+CGMR | Query module version information | OK |
| AT+CGSN | Query IMEI number | OK |
| AT+CCID | Query SIM card ICCID number5 | OK |
| AT+CIMI | Query IMSI | OK |
| ATI | Query product information | OK |
| AT+VER | Query module internal software version | OK |
| AT^HVER | Query platform hardware version | OK |
| AT*I | Query various information (manufacturer name, module model, module version, hardware version, firmware compilation time, IMEI number, ICCID number, international mobile terminal user identification code) | OK |
| AT+RESET | Restart module | OK |
| AT+RSTSET | Restart module and restore factory settings | OK |
| AT*EXINFO? | Query boot cause value | OK |
| AT+IPR? | Query TE-TA baud rate | OK |
| AT+CREG? | Query network registration status | OK |
| AT+CSQ | Query signal quality | OK |
| AT+CPIN? | Query whether the sim card is normal | OK |
| AT+CGATT? | Query whether it is attached to the data network | OK |
Note: This AT command is case insensitive
Caution: Upon connecting the module to a computer, three COM ports will appear, of which only one is designated for AT command debugging. The remaining two COM ports are not operational.
MQTT AT Commands
| Command | Meaning | Return Value |
|---|---|---|
| AT+MCONFIG="clientid","user","password" | Set MQTT related parameters | OK |
| AT+MIPSTART="svraddr","port" | Establish TCP connection | CONNECT OK |
| AT+MCONNECT=clean_session, keepalive | Client requests session connection to server | CONNACK OK |
| AT+MSUB="topic",qos | Subscribe to topic | SUBACK |
| AT+MPUB="topic",qos,retain,"message" | Publish message |
Query of Return Value Results and Meaning
| Detailed Result Code | Meaning |
|---|---|
| OK | Command executed, no error |
| CONNECT | Connection successful |
| +CME ERROR:10 | SIM card not inserted |
| +CME ERROR:network timeout | Network timeout |
| CONNACK OK | Connection successful |
| ERROR | Connection failed |
| +CME ERROR:SIM busy | SIM card busy |
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