Shanghai SIMCom Wireless Solutions Ltd.
www.simcom.com
SIM7500_SIM7600_SIM7800
Series_MQTT_AT Command Manual_V1.00
LTE Module
Building A, SIM Technology Building, No.633, Jinzhong Road
Changning District 200335
Tel:86-21-31575100/31575200
support@simcom.com
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Series_MQTT_AT Command
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command
Document Title:
Version:
Date:
Status:
Document ID:
SIM7500_SIM7600_SIM7800
Manual
1.00
2018-10-12
Release
Manual_V1.00
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 SIMCom Limited., 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. 2018
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 1 / 41
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Version History
Version Date Chapter What is new
V1.00 2018-09-28 New version
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 2 / 41
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Contents
Version History .................................................................................................................................. 2
Contents ............................................................................................................................................ 3
1 Introduction ................................................................................................................................ 4
1.1 The SSL Context Management AT Commands (for SSL/TLS MQTT) .................................................. 4
1.2 The process of Using MQTT AT Commands ..................................................................................... 4
2 Description of AT Command ........................................................................................................... 5
2.1 SSL Context Management AT (only for SSL/TLS MQTT) .................................................................. 5
2.1.1 AT+CSSLCFG Configure the SSL Context ........................................................................... 5
2.1.2 AT+CCERTDOWN Download certificate into the module ..................................................... 9
2.1.3 AT+CCERTLIST List certificates ........................................................................................ 9
2.1.4 AT+CCERTDELE Delete certificates ................................................................................. 10
2.2 MQTT Services AT ....................................................................................................................... 11
2.2.1 AT+CMQTTSTART Start MQTT service ........................................................................... 11
2.2.2 AT+CMQTTSTOP Stop MQTT service .............................................................................. 11
2.2.3 AT+CMQTTACCQ Acquire a client .................................................................................. 12
2.2.4 AT+CMQTTREL Release a client ...................................................................................... 13
2.2.5 AT+CMQTTSSLCFG Set the SSL context (only for SSL/TLS MQTT) ................................. 13
2.2.6 AT+CMQTTWILLTOPIC Input the topic of will message .................................................... 14
2.2.7 AT+CMQTTWILLMSG Input the will message .................................................................. 15
2.2.8 AT+CMQTTCONNECT Connect to MQTT server .............................................................. 16
2.2.9 AT+CMQTTDISC Disconnect from server ......................................................................... 17
2.2.10 AT+CMQTTTOPIC Input the topic of publish message...................................................... 18
2.2.11 AT+CMQTTPAYLOAD Input the publish message ........................................................... 19
2.2.12 AT+CMQTTPUB Publish a message to server .................................................................. 20
2.2.13 AT+CMQTTSUBTOPIC Input the topic of subscribe message ............................................ 21
2.2.14 AT+CMQTTSUB Subscribe a message to server ............................................................... 22
2.2.15 AT+CMQTTUNSUBTOPIC Input the topic of unsubscribe message ................................... 23
2.2.16 AT+CMQTTUNSUB Unsubscribe a message to server ...................................................... 24
2.2.17 AT+CMQTTCFG Configure the MQTT Context ............................................................... 25
2.3 Command result codes and unsolicited codes .................................................................................. 26
2.3.1 Command result <err> codes ............................................................................................... 26
2.3.2 Unsolicited result codes ....................................................................................................... 27
3 Example ........................................................................................................................................ 29
3.1 Access to MQTT server not SSL/TLS ............................................................................................. 30
3.2 Connect to SSL/TLS MQTT server (not verify server) ..................................................................... 32
3.3 Access to SSL/TLS MQTT server (only verify the server) ................................................................ 34
3.4 Access to SSL/TLS MQTT server (verify server and client) .............................................................. 36
3.5 Access to MQTT server without checking UTF8 coding ................................................................... 39
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 3 / 41
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This document is a reference guide to all the AT commands defined for MQTT. Through these MQTT AT
commands, you can communicate with a MQTT server.
1 Introduction
1.1 The SSL Context Management AT Commands (for SSL/TLS MQTT)
Step 1: Configure SSL version by AT+CSSLCFG=“sslversion”,<ssl_ctx_index>,<sslversion>.
Step 2: Configure SSL authentication mode by AT+CSSLCFG=“authmode”,<ssl_ctx_index>, <authmode>.
Step 3: Configure the flag of ignore local time by
AT+CSSLCFG=“ignorlocaltime”,<ssl_ctx_index>,<ignoreltime>.
Step 4: Configure the max time in SSL negotiation stage by
AT+CSSLCFG=“negotiatetime”,<ssl_ctx_index>,<negotiatetime>.
Step 5: Configure the server root CA by AT+CSSLCFG=“cacert”,<ssl_ctx_index>,<ca_file>.
Step 6: Configure the client certificate by AT+CSSLCFG=“clientcert”,<ssl_ctx_index>,<clientcert_file>.
Step 7: Configure the client key by AT+CSSLCFG=“clientkey”,<ssl_ctx_index>,<clientkey_file>.
Step 8: Download the certificate into the module by AT+CCERTDOWN.
Step 9: Delete the certificate from the module by AT+CCERTDELE.
Step 10: List the certificates by AT+CCERTLIST.
1.2 The process of Using MQTT AT Commands
Step 1: Ensure GPRS network is available before performing SSL related operations.
Step 2: Configure the parameter of PDP context by AT+CGDCONT.
Step 3: Activate the PDP context to start MQTT service by AT+CMQTTSTART.
Step 4: Acquire a client by AT+CMQTTACCQ.
Step 5: Configure SSL context by AT+CSSLCFG (if connect to SSL/TLS MQTT server).
Step 6: Set the SSL context used in SSL connection by AT+CMQTTSSLCFG (if connect to SSL/TLS MQTT
server).
Step 7: Connect to MQTT server by AT+CMQTTCONNECT.
Step 8: Subscribe to message by AT+CMQTTSUB.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 4 / 41
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3,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
Step 9: Unsubscribe to message by AT+CMQTTUNSUB.
Step 10: Input the topic of a publish message by AT+CMQTTTOPIC.
Step 11: Input the payload of a publish message by AT+CMQTTPAYLOAD.
Step 12: Publish message by AT+CMQTTPUB.
Step 13: Disconnect from the server by AT+CMQTTDISC.
Step 13: Release the client by AT+CMQTTREL.
Step 14: Deactivate the PDP context to stop MQTT service by AT+CMQTTSTOP.
2 Description of AT Command
2.1 SSL Context Management AT (only for SSL/TLS MQTT)
2.1.1 AT+CSSLCFG Configure the SSL Context
AT+CSSLCFG Configure the SSL Context
Response
+CSSLCFG: "sslversion",(0-9),(0-4)
+CSSLCFG: "authmode",(0-9),(0-3)
+CSSLCFG: "ignorelocaltime",(0-9),(0,1)
Test Command
AT+CSSLCFG=?
Read Command
AT+CSSLCFG?
+CSSLCFG: "negotiatetime",(0-9),(10-300)
+CSSLCFG: "cacert",(0-9),(5-128)
+CSSLCFG: "clientcert",(0-9),(5-128)
+CSSLCFG: "clientkey",(0-9),(5-128)
OK
Response
+CSSLCFG:
0,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
1,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
2,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 5 / 41
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OK
dex>,<sslversion>
ERROR
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
4,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
5,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
6,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
7,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
8,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
+CSSLCFG:
9,<sslversion>,<authmode>,<ignoreltime>,<negotiatetime>,<
ca_file>,<clientcert_file>,<clientkey_file>
Write Command
/*Query the configuration of the specified
SSL context*/
AT+CSSLCFG=<ssl_ctx_index>
Write Command
/*Configure the version of the specified SSL
context*/
AT+CSSLCFG="sslversion",<ssl_ctx_in
Write Command
/*Configure the authentication mode of the
specified SSL context*/
AT+CSSLCFG="authmode",<ssl_ctx_in
dex>,<authmode>
Write Command
/*Configure the ignore local time flag of the
specified SSL context*/
AT+CSSLCFG="ignorelocaltime",<ssl_c
tx_index>,<ignoreltime>
Write Command
Response
+CSSLCFG:
<ssl_ctxindex>,<sslversion>,<authmode>,<ignoreltime>,<ne
gotiatetime>,<ca_file>,<clientcert_file>,<clientkey_file>
OK
Response
a)If successfully:
OK
b)If failed:
Response
a)If successfully:
OK
b)If failed:
ERROR
Response
a)If successfully:
OK
b)If failed:
ERROR
Response
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 6 / 41
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_index>,<negotiatetime>
ERROR
Configure the server root CA of the
Configure the client certificate of the
Configure the client key of the specified
should use the default value if you can’t confirm the version
<authmode>
1 – ignore time check for certification
/*Configure the negotiate timeout value of the
specified SSL context*/
AT+CSSLCFG="negotiatetime",<ssl_ctx
Write Command
/*
specified SSL context*/
AT+CSSLCFG="cacert",<ssl_ctx_index>
,<ca_file>
Write Command
/*
specified SSL context*/
AT+CSSLCFG="clientcert",<ssl_ctx_ind
ex>,<clientcert_file>
Write Command
/*
SSL context*/
AT+CSSLCFG="clientkey",<ssl_ctx_ind
ex>,<clientkey_file>
Defined Values
<ssl_ctx_index>
a)If successfully:
OK
b)If failed:
Response
a)If successfully:
OK
b)If failed:
ERROR
Response
a)If successfully:
OK
b)If failed:
ERROR
Response
a)If successfully:
OK
b)If failed:
ERROR
The SSL context ID. The range is 0-9.
<sslversion>
<ignoreltime>
The SSL version, the default value is 4.
0 – SSL3.0
1 – TLS1.0
2 – TLS1.1
3 – TLS1.2
4 – All
The configured version should be support by server. So you
which the server supported.
The authentication mode, the default value is 0.
0 – no authentication.
1 –server authentication. It needs the root CA of the server.
2 –server and client authentication. It needs the root CA of the
server, the cert and key of the client.
3–client authentication and no server authentication. It needs the
cert and key of the client.
The flag to indicate how to deal with expired certificate, the
default value is 1.
0 – care about time check for certification.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 7 / 41
<negotiatetime>
value used in SSL negotiate stage. The range is
The root CA file name of SSL context. The file name must have
type like “.pem” or “.der”.The length of filename is from 5 to
ASCII characters, the file path
ascii} and the
quotation mark (The string in the quotation mark should be
SIM7500_SIM7600_SIM7800 Series_FTPS_AT Command
and SIM7500_SIM7600_SIM7800 Series_HTTP_AT
ASCII characters, the file path
ascii} and the
mark should be
SIM7500_SIM7600_SIM7800 Series_FTPS_AT Command
600_SIM7800 Series_HTTP_AT
Command Manual
The client key file name of SSL context. The file name must
ascii} and the
quotation mark (The string in the quotation mark should be
<ca_file>
Smart Machine Smart Decision
When set the value to 0, it need to set the right current date and
time by AT+CCLK when need SSL certification.
The timeout
10-300 seconds. The default value is 300.
128 bytes.
If the filename contains non-
parameter should contain a prefix of {non-
hexadecimal of the filename’s UTF8 code).
There are two ways to download certificate files to module:
1. By AT+CCERTDOWN.
2. By FTPS or HTTPS commands. Please refer to:
Manual
Command Manual
<clientcert_file>
The client cert file name of SSL context. The file name must
have type like “.pem” or “.der”.The length of filename is from 5
to 128 bytes.
If the filename contains non-
parameter should contain a prefix of {non-
quotation mark (The string in the quotation
hexadecimal of the filename’s UTF8 code).
There are two ways to download certificate files to module:
1. By AT+CCERTDOWN.
2. By FTPS or HTTPS commands. Please refer to:
Manual and SIM7500_SIM7
<clientkey_file>
have type like “.pem” or “.der”.The length of filename is from 5
to 128 bytes.
If the filename contains non-ASCII characters, the file path
parameter should contain a prefix of {non-
hexadecimal of the filename’s UTF8 code).
There are two ways to download certificate files to module:
1. By AT+CCERTDOWN.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 8 / 41
2. By FTPS or HTTPS commands. Please refer to:
SIM7500_SIM7600_SIM7800 Series_FTPS_AT Command
Command Manual
Response
<filename>
The name of the certificate/key file. The file name must have
ASCII characters, the file path
ascii} and the
quotation mark should be
) of UTF8
Manual and SIM7500_SIM7600_SIM7800 Series_HTTP_AT
2.1.2 AT+C CERTDOWN Download certificate into the module
AT+CCERTDOWN Download certificate into the module
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Test Command
AT+CCERTDOWN=?
Write Command
AT+CCERTDOWN=<filename>,<len>
Defined Values
<len>
+CCERTDOWN: (5-128),(1-10240)
OK
Response
a)If it can be download:
>
<input data here>
b)If failed:
ERROR
type like “.pem” or “.der”. The length of filename is from 5 to
128 bytes.
If the filename contains non-
parameter should contain a prefix of {non-
quotation mark (The string in the
hexadecimal of the filename’s UTF8 code).
For example: If you want to download a file with name “中
华.pem”, you should convert the “中华.pem” to UTF8 coding
(中华.pem), then input the hexadecimal
(262378344532443B262378353334453B2E70656D
coding.
The length of the file data to send. The range is from 1 to 10240
bytes.
2.1.3 AT+C CERTLIST List certificates
AT+CCERTLIST List certificates
Execute Command
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 9 / 41
Response
AT+CCERTLIST [+CCERTLIST:<file_name>
The certificate/key files which has been downloaded to the
ERROR
The name of the certificate/key file. The file name must have
ASCII characters, the file path
ascii} and the
quotation mark (The string in the quotation mark should be
) of UTF8
[+CCERTLIST:<file_name>]
…
<CR><LF>]
OK
Defined Values
<filename>
module.
If the filename contains non-ASCII characters, it will show the
non-ASCII characters as UTF8 code.
2.1.4 AT+C CERTDELE Delete certificates
AT+CCERTDELE Delete certificate from the module
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Response
Write Command
AT+CCERTDELE=<filename>
Defined Values
<filename>
a)If delete successfully:
OK
b)If failed:
type like “.pem” or “.der”. The length of filename is from 5 to
128 bytes.
If the filename contains non-
parameter should contain a prefix of {non-
hexadecimal of the filename’s UTF8 code).
For example: If you want to download a file with name “中
华.pem”, you should convert the “中华.pem” to UTF8 coding
(中华.pem), then input the hexadecimal
(262378344532443B262378353334453B2E70656D
coding.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 10 / 41
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2.2 MQTT Services AT
2.2.1 AT+CMQTTSTART Start MQTT service
AT+CMQTTSTART is used to start MQTT service by activating PDP context. You must execute this command
before any other MQTT related operations.
AT+CMQTTSTART Start MQTT service
Response
a)If start MQTT service successfully:
OK
+CMQTTSTART: <err>
b)If start MQTTservice successfully:
Execute Command
AT+CMQTTSTART
Maximum Response Time
+CMQTTSTART: <err>
OK
c)If failed:
ERROR
d)If failed:
ERROR
+CMQTTSTART: <err>
120000ms
Defined Values
<err>
The result code, please refer to chapter 2.3.1
2.2.2 AT+CMQTTSTOP Stop MQTT service
AT+CMQTTSTOP is used to stop MQTT service.
AT+CMQTTSTOP STOP MQTT service
Response
a)If stop MQTT service successfully:
Execute Command
AT+CMQTTSTOP
+CMQTTSTOP: <err>
OK
b)If stop MQTT service successfully:
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 11 / 41
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ERROR
numeric parameter that identifies a client. The range of
encoded string. It specifies a unique identifier for the
OK
+CMQTTSTOP: <err>
c)If failed:
ERROR
Defined Values
<err>
The result code, please refer to chapter 2.3.1
2.2.3 AT+CMQTTACCQ Acquire a client
AT+CMQTTACCQ is used to acquire a MQTT client. It must be called before all commands about MQTT
connect and after AT+CMQTTSTART
AT+CMQTTACCQ Acquire a client
.
Test Command
AT+CMQTTACCQ=?
Read Command
AT+CMQTTACCQ?
Write Command
AT+CMQTTACCQ=<client_index>,
<clientID>[, <server_type>]
Defined Values
<client_index>
<clientID>
<server_type>
Response
+CMQTTACCQ: (0-1),(1-23),(0-1)
OK
Response
+CMQTTACCQ: <client_index>, <clientID>,<server_type>
+CMQTTACCQ: <client_index>, <clientID>,<server_type>
OK
Response
a)If successfully:
OK
b)If failed:
+CMQTTACCQ: <client_index>,<err>
ERROR
c) If failed:
A
permitted values is 0 to 1.
The UTF-
client. The string length is from 1 to 23 bytes.
A numeric parameter that identifies the server type. The default
value is 0.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 12 / 41
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numeric parameter that identifies a client. The range of
<err>
The result code, please refer to chapter 2.3.1.
0 - MQTT server with TCP
1-MQTT server with SSL/TLS
<err>
The result code, please refer to chapter 2.3.1
2.2.4 AT+CMQTTREL Release a client
AT+CMQTTREL is used to release a MQTT client. It must be called after AT+CMQTTDISC and before
AT+CMQTTSTOP
AT+CMQTTREL Release a client
Test Command
AT+CMQTTREL=?
Read Command
AT+CMQTTREL?
Write Command
AT+CMQTTREL=<client_index>
Defined Values
<client_index>
.
Response
+CMQTTREL: (0-1)
OK
Response
OK
Response
a)If successfully:
OK
b)If failed:
+CMQTTREL: <client_index>,<err>
ERROR
c) If failed:
ERROR
A
permitted values is 0 to 1.
2.2.5 AT+CMQTTSSLCFG Set the SSL context (only for SSL/TLS MQTT)
AT+CMQTTSSLCFG is used to set the SSL context which to be used in the SSL connection when it will connect
to a SSL/TLS MQTT server.
The setting will be cleared after the CMQTTCONNECT operation is finished.
NOTE: If you don’t set the SSL context by this command before connecting to server by
AT+CMQTTCONNECT, the CMQTTCONNECT operation will use the SSL context as same as index
<session_id> (the 1st parameter of AT+ CMQTTCONNECT) when connecting to the server.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 13 / 41
It must be called before AT+CMQTTCONNECT and after AT+CMQTTSTART.
Response
The SSL context ID which will be used in the SSL connection.
Refer to the <ssl_ctx_index> of AT+CSSLCFG
c)If failed:
AT+CCHSSLCFG Set the SSL context
Test Command
AT+CMQTTSSLCFG=?
Read Command
AT+CMQTTSSLCFG?
Smart Machine Smart Decision
Response
+ CMQTTSSLCFG: (0,1),(0-9)
OK
Response
+CMQTTSSLCFG: <session_id>,[<ssl_ctx_index >]
+CMQTTSSLCFG: <session_id>,[<ssl_ctx_index >]
OK
Write Command
AT+CMQTTSSLCFG=<session_id>,<ssl
_ctx_index>
Defined Values
<session_id>
<ssl_ctx_index>
a)If successfully:
OK
b)If failed:
ERROR
The session_id to operate. It’s from 0 to 1
2.2.6 AT+CMQTTWILLTOPIC Input the topic of will message
AT+CMQTTWILLTOPIC is used to input the topic of will message.
AT+CMQTTWILLTOPIC Input the will topic
Response
Test Command
AT+CMQTTWILLTOPIC=?
Write Command
AT+CMQTTWILLTOPIC=<client_index
>,<req_length>
+CMQTTWILLTOPIC: (0-1),(1-1024)
OK
Response
a)If successfully:
>
<input data here>
OK
b)If failed:
+CMQTTWILLTOPIC: <client_index>,<err>
ERROR
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 14 / 41
ERROR
values is 0 to 1.
<req_length>
OK
ERROR
numeric parameter that identifies a client. The range of
should be
UTF-encoded string. The range is from 1 to 10240 bytes.
Defined Values
<client_index>
<err>
A numeric parameter that identifies a client. The range of permitted
The length of input topic. The will topic should be UTF-encoded
string. The range is from 1 to 1024 bytes.
The result code, please refer to chapter 2.3.1
2.2.7 AT+CMQTTWILLMSG Input the will message
AT+CMQTTWILLMSG is used to input the message body of will message.
AT+CMQTTWILLTOPIC Input the will message
Response
Test Command
AT+CMQTTWILLMSG=?
+CMQTTWILLMSG: (0-1),(1-10240),(0-2)
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Write Command
AT+CMQTTWILLMSG=<client_index>,
<req_length>,<qos>
Defined Values
<client_index>
<req_length>
<qos>
<err>
Response
a)If successfully:
>
<input data here>
OK
b)If failed:
+CMQTTWILLMSG: <client_index>,<err>
ERROR
c)If failed:
A
permitted values is 0 to 1.
The length of input data. The will message
The qos value of the will message. The range is from 0 to 2.
The result code: 0 is success. Other values are failure. Please
refer to chapter 2.3.1
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 15 / 41
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OK
ERROR
numeric parameter that identifies a client. The range of
of the string length is 9 to 256 bytes. The string should be like
2.2.8 AT+CMQTTCONNECT Connect to MQTT server
AT+CMQTTCONNECT is used to connect to a MQTT server.
NOTE: If you don’t set the SSL context by AT+CMQTTSSLCFG before connecting a SSL/TLS MQTT server by
AT+CMQTTCONNECT, it will use the <client_index> (the 1st parameter of AT+CMQTTCONNNECT) SSL
context when connecting to the server.
AT+CMQTTCONNECT Connect to MQTT server
Response
Test Command
AT+CMQTTCONNECT=?
Read Command
AT+CMQTTCONNECT?
Write Command
AT+CMQTTCONNECT=<client_index>,
<server_addr>,<keepalive_time>,<clean_
session>[,<user_name>[,<pass_word>]]
+CMQTTCONNECT: (0-1),(9-256),(60-64800),(0-1)
Response
+CMQTTCONNECT:
0[,<server_addr>,<keepalive_time>,<clean_session>[,<user_
name>[,<pass_word>]]]
+CMQTTCONNECT:
1[,<server_addr>,<keepalive_time>,<clean_session>[,<user_
name>[,<pass_word>]]]
OK
Response
a)If successfully:
OK
+CMQTTCONNECT: <client_index>,0
b)If failed:
OK
+CMQTTCONNECT: <client_index>,<err>
c)If failed:
+CMQTTCONNECT: <client_index>,<err>
ERROR
d)If failed:
Defined Values
<client_index>
<server_addr>
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 16 / 41
A
permitted values is 0 to 1.
The string that described the server address and port. The range
65:5141”, must begin with “tcp://”. If
<keepalive_time>
alive packet when there is no
the server must store the subscriptions of the client after it
2 messages for the subscribed topics so that they can be
delivered when the client reconnects. The server must also
flight messages being delivered at the
the server must discard any previously maintained
The server must also discard any state when the client
The password corresponding to the user which can be used for
. The string length is
refer to chapter 2.3.1.
AT+CMQTTDISC Disconnect from server
Smart Machine Smart Decision
this “tcp://116.247.119.1
the <server_addr> not include the port, the default port is 1883.
The time interval between two messages received from a client.
The client will send a keep-
message sent to server after song long time. The range is from
60s to 64800s (18 hours).
The clean session flag. The value range is from 0 to 1, and
default value is 0.
0 -
disconnected. This includes continuing to store QoS 1 and QoS
<clean_session>
<user_name>
<password>
<err>
maintain the state of in-
point the connection is lost. This information must be kept until
the client reconnects.
1 -
information about the client and treat the connection as "clean".
disconnects.
The user name identifies the name of the user which can be used
for authentication when connecting to server. The string length
is from 1 to 256 bytes.
authentication when connecting to server
from 1 to 256 bytes.
The result code: 0 is success. Other values are failure. Please
2.2.9 AT+CMQTTDISC Disconnect from server
AT+ CMQTTDISC is used to disconnect from the server.
Response:
Test Command
AT+CMQTTDISC=?
Read Command
AT+CMQTTDISC?
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 17 / 41
+CMQTTDISC: (0-1),(0, 60-180)
OK
Response:
+CMQTTDISC: 0,<disc_state>
+CMQTTDISC: 1,<disc_state>
Write Command
AT+CMQTTDISC=<client_index>,<time
out>
Defined Values
<client_index>
<timeout>
<disc_state>
<err>
Smart Machine Smart Decision
OK
Response
a)If connect successfully：
+CMQTTDISC: <client_index>,0
OK
b)If connect successfully：
OK
+CMQTTDISC: <client_index>,0
c)
If failed：
OK
+CMQTTDISC: <client_index>,<err>
d)If failed:
ERROR
e)If failed:
+CMQTTDISC: <client_index>,<err>
ERROR
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The timeout value for disconnection. The unit is second. The range
is 60s to 180s. The default value is 0s (not set the timeout value).
1 - disconnection
0 - connection
The result code: 0 is success. Other values are failure. Please refer
to chapter 2.3.1.
2.2.10 AT+CMQTTTOPIC Input the topic of publish message
AT+CMQTTTOPIC is used to input the topic of a publish message.
NOTE: The topic will be clean after execute AT+CMQTTPUB.
AT+CMQTTTOPIC Input the publish message topic
Test Command
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 18 / 41
Response
+CMQTTTOPIC: (0-1),(1-1024)
AT+CMQTTTOPIC=?
values is 0 to 1.
ERROR
Write Command
AT+CMQTTTOPIC=<client_index>,<re
q_length>
Defined Values
<client_index>
Smart Machine Smart Decision
OK
Response
a)If successfully:
>
<input data here>
OK
b)If failed:
+CMQTTTOPIC: <client_index>,<err>
ERROR
c)If failed:
ERROR
A numeric parameter that identifies a client. The range of permitted
<req_length>
<err>
The length of input topic data. The publish message topic should be
UTF-encoded string. The range is from 1 to 1024 bytes.
The result code: 0 is success. Other values are failure. Please refer
to chapter 2.3.1.
2.2.11 AT+ CMQTTPAYLOAD Input the publish message
AT+CMQTTPAYLOAD is used to input the message body of a publish message.
NOTE: The payload will be clean after execute AT+CMQTTPUB.
AT+CMQTTPAYLOAD Input the publish message body
Response
Test Command
AT+CMQTTPAYLOAD=?
Write Command
AT+CMQTTPAYLOAD=<client_index>,
<req_length>
+CMQTTPAYLOAD: (0-1),(1-10240)
OK
Response
a)If successfully:
>
<input data here>
OK
b)If failed:
+CMQTTPAYLOAD: <client_index>,<err>
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 19 / 41
c)If failed:
to chapter 2.3.1.
<client_index>
A numeric parameter that identifies a client. The range of permitted
ERROR
Defined Values
<client_index>
<req_length>
<err>
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The length of input message data. The publish message should be
UTF-encoded string. The range is from 1 to 10240 bytes.
The result code: 0 is success. Other values are failure. Please refer
2.2.12 AT+CMQTTPUB Publish a message to server
AT+CMQTTPUB is used to publish a message to MQTT server.
NOTE: The topic and payload will be clean after execute AT+CMQTTPUB.
AT+CMQTTPUB Publish a message to server
Smart Machine Smart Decision
Test Command
AT+CMQTTPUB=?
Write Command
AT+CMQTTPUB=<client_index>,<qos>,
<pub_timeout>[,<ratained> [,<dup>]]
Defined Values
Response
+CMQTTPUB (0-1),(0-2),(60-180),(0-1),(0-1)
OK
Response
a)If successfully:
OK
+CMQTTPUB: <client_index>,0
b)If failed:
OK
+CMQTTPUB: <client_index>,<err>
c)If failed:
+CMQTTPUB: <client_index>,<err>
ERROR
d)If failed:
ERROR
values is 0 to 1.
<qos>
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 20 / 41
The publish message’s qos. The range is from 0 to 2.
<pub_timeout>
message to server, it will report failed if the client receive no
from 60s to 180s.
OK
ERROR
Smart Machine Smart Decision
0 – at most once
1 – at least once
2 – exactly once
The publishing timeout interval value. Since the client publish a
response from server after the timeout value seconds. The range is
<ratained>
<dup>
<err>
The retain flag of the publish message. The value is 0 or 1. The
default value is 0.
When a client sends a PUBLISH to a server, if the retain flag is set
to 1, the server should hold on to the message after it has been
delivered to the current subscribers.
The dup flag to the message. The value is 0 or 1. The default value
is 0. The flag is set when the client or server attempts to re-deliver
a message.
The result code: 0 is success. Other values are failure. Please refer
to chapter 2.3.1.
2.2.13 AT+CMQTTSUBTOPIC Input the topic of subscribe message
AT+CMQTTSUBTOPIC is used to input the topic of a subscribe message.
NOTE: The topic will be clean after execute AT+CMQTTSUB.
AT+CMQTTSUBTOPIC Input a subscribe message topic
Response
Test Command
AT+CMQTTSUBTOPIC=?
+CMQTTSUBTOPIC: (0-1),(1-1024)
Response
a)If successfully:
>
<input data here>
Write Command
AT+CMQTTSUBTOPIC=<client_index>
,<req_length>,<qos>
Defined Values
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 21 / 41
OK
b)If failed:
+CMQTTSUBTOPIC: <client_index>,<err>
ERROR
c)If failed:
Smart Machine Smart Decision
<err>
The result code: 0 is success. Other values are failure. Please refer
ERROR
Response
OK
<client_index>
<req_length>
<qos>
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The length of input topic data. The publish message topic should be
UTF-encoded string. The range is from 1 to 1024 bytes.
The publish message’s qos. The range is from 0 to 2.
0 – at most once
1 – at least once
2 – exactly once
to chapter 2.3.1.
2.2.14 AT+CMQTTSUB Subscribe a message to server
AT+CMQTTSUB is used to subscribe a message to MQTT server.
NOTE: The topic will be clean after execute AT+CMQTTSUB.
AT+CMQTTSUB Subscribe a message to server
Response
Test Command
AT+CMQTTSUB=?
Write Command
/* subscribe one or more topics which input
by AT+CMQTTSUBTOPIC*/
AT+CMQTTSUB=<client_index>[,<dup>
]
+CMQTTSUB (0-1),(0-1024),(0-2),(0-1)
OK
Response
a)If successfully:
OK
+CMQTTSUB: <client_index>,0
b)If failed:
OK
+CMQTTSUB: <client_index>,<err>
c)If failed:
+CMQTTSUB: <client_index>,<err>
ERROR
d)If failed:
Write Command
/* subcribe one topic*/
AT+CMQTTSUB=<client_index>,<reqLe
ngth>,<qos>[,<dup>]
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 22 / 41
a)If successfully:
>
<input data here>
topic should be
<dup>
The dup flag to the message. The value is 0 or 1. The default value
<err>
AT+CMQTTUNSUBTOPIC=<client_ind
Defined Values
<client_index>
<req_length>
<qos>
Smart Machine Smart Decision
+CMQTTSUB: <client_index>,<err>
b)If failed:
OK
+CMQTTSUB: <client_index>,<err>
c)If failed:
+CMQTTSUB: <client_index>,<err>
ERROR
d)If failed:
ERROR
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The length of input topic data. The message
UTF-encoded string. The range is from 1 to 1024 bytes.
The publish message’s qos. The range is from 0 to 2.
0 – at most once
1 – at least once
2 – exactly once
is 0. The flag is set when the client or server attempts to re-deliver
a message.
The result code: 0 is success. Other values are failure. Please refer
to chapter 2.3.1.
2.2.15 AT+CMQTTUNSUBTOPIC Input the topic of unsubscribe message
AT+CMQTTUNSUBTOPIC is used to input the topic of a unsubscribe message.
NOTE: The topic will be clean after execute AT+CMQTTUNSUB.
AT+CMQTTUNSUBTOPIC Input a unsubscribe message topic
Response
Test Command
AT+CMQTTUNSUBTOPIC=?
Write Command
+CMQTTUNSUBTOPIC: (0-1),(1-1024)
OK
Response
a)If successfully:
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 23 / 41
ex>,<req_length> >
<client_index>
Defined Values
<req_length>
<err>
Smart Machine Smart Decision
<input data here>
OK
b)If failed:
+CMQTTUNSUBTOPIC: <client_index>,<err>
ERROR
c)If failed:
ERROR
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The length of input topic data. The publish message topic should be
UTF-encoded string. The range is from 1 to 1024 bytes.
The result code: 0 is success. Other values are failure. Please refer
to chapter 2.3.1.
2.2.16 AT+CMQTTUNSUB Unsubscribe a message to server
AT+CMQTTUNSUB is used to unsubscribe a message to MQTT server.
NOTE: The topic will be clean after execute AT+CMQTTUNSUB.
AT+CMQTTSUB Subscribe a message to server
Response
Test Command
AT+CMQTTUNSUB=?
Write Command
/* unsubscribe one or more topics which input
by AT+CMQTTUNSUBTOPIC*/
AT+CMQTTUNSUB=<client_index>,<du
p>
+CMQTTUNSUB (0-1),(0-1024),(0-1)
OK
Response
a)If successfully:
OK
+CMQTTUNSUB: <client_index>,0
OK
+CMQTTUNSUB: <client_index>,<err>
b)If failed:
OK
+CMQTTUNSUB: <client_index>,<err>
c)If failed:
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 24 / 41
Write Command
ERROR
topic should be
UTF-encoded string. The range is from 1 to 1024 bytes.
AT+CSSLCFG Configure the SSL Context
/* unsubscribe one topic*/
AT+CMQTTUNSUB=<client_index>,<re
qLength>,<dup>
Smart Machine Smart Decision
+CMQTTUNSUB: <client_index>,<err>
ERROR
d)If failed:
ERROR
Response
a)If successfully:
>
<input data here>
b)If failed:
OK
+CMQTTUNSUB: <client_index>,<err>
c)If failed:
+CMQTTUNSUB: <client_index>,<err>
ERROR
d)If failed:
Defined Values
<client_index>
<req_length>
<dup>
<err>
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The length of input topic data. The message
The dup flag to the message. The value is 0 or 1. The default value
is 0. The flag is set when the client or server attempts to re-deliver
a message.
The result code: 0 is success. Other values are failure. Please refer
to chapter 2.3.1.
2.2.17 AT+CMQTTCFG Configure the MQTT Context
Response
Test Command
AT+CMQTTCFG=?
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 25 / 41
+CMQTTCFG: "checkUTF8",(0-1),(0-1)
OK
Read Command
<index>
1 – Check UTF8 coding.
AT+CMQTTCFG?
Smart Machine Smart Decision
Response
+CMQTTCFG: 0,<checkUTF8_flag>
+CMQTTCFG: 1, <checkUTF8_flag>
OK
Write Command
/*Configure the check UTF8 flag of the
specified MQTT client context*/
AT+CMQTTCFG="checkUTF8",<index
>,<checkUTF8_flag>
Defined Values
<checkUTF8_flag>
Response
a)If successfully:
OK
b)If failed:
ERROR
The MQTT client index. The range is 0-1.
The flag to indicate whether to check the string is UTF8 coding
or not, the default value is 1.
0 – Not check UTF8 coding.
2.3 Command result codes and unsolicited codes
2.3.1 Command result <err> codes
Result codes
0
1 failed
2 bad UTF-8 string
3 sock connect fail
4
5 sock close fail
6 message receive fail
7 network open fail
8
9 network not opened
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 26 / 41
operation succeeded
sock create fail
network close fail
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+CMQTTCONNLOST:
When client disconnect passively, URC
“+CMQTTCONNLOST” will be reported, then user need to
connect MQTT server again.
<cause>
10
11 no connection
12 invalid parameter
13 not supported operation
14
15 require connection fail
16 sock sending fail
17 timeout
18
19 client is used
20 client not acquired
21 client not released
22
23 network is opened
24 packet fail
25 DNS error
26
client index error
client is busy
topic is empty
length out of range
socket is closed by server
27 connection refused: unaccepted protocol version
28 connection refused: identifier rejected
29 connection refused: server unavailable
30
31 connection refused: not authorized
32 handshake fail
33 not set certificate
connection refused: bad user name or password
2.3.2 Unsolicited result codes
2.3.2.1 Disconnected by server
Unsolicited codes
<client_index>,<cause>
Defined Values
<client_index>
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 27 / 41
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The cause of disconnection.
1 – Socket is closed passively.
If a client subscribes to one or more topics, any message
following URC is used for transmitting the message published
At the beginning of receiving published message, the
report this to user, and indicate client index with
TRXSTART” received, the
module will report the second message to user, and indicate
client index with <client_index>, the topic packet length with
<sub_topic_len> and the topic content with <sub_topic> after
once with the rest of topic content. The sum of <sub_topic_len>
and “+CMQTTRXTOPIC” received, the
with <client_index>, the payload packet length with
<sub_payload_len> and the payload content with
At last, the module will send fourth message to user and
2 – Socket is reset.
3 – Network is closed.
2.3.2.2 Receive publish message from MQTT server
If a client subscribes to one or more topics, any message published to those topics are sent by the server to the
client.
Unsolicited codes
+CMQTTRXSTART:
<client_index>,<topic_total_len>,<payloa
d_total_len>
+CMQTTRXTOPIC:
<client_index>,<sub_topic_len>
<sub_topic>
/*for long topic, split to multiple packets to
report*/
[<CR><LF>+CMQTTRXTOPIC:
<client_index>,<sub_topic_len>
<sub_topic>]
+CMQTTRXPAYLOAD:
<client_index>,<sub_payload_len>
<sub_payload>
/*for long payload, split to multiple packets to
report*/
[+CMQTTRXPAYLOAD:
<client_index>,<sub_payload_len>
<sub_payload>]
+CMQTTRXEND: <client_index>
published to those topics are sent by the server to the client. The
from server to client.
1)+CMQTTRXSTART:
<client_index>,<topic_total_len>,<payload_total_len>
module will
<client_index>, the topic total length with <topic_total_len> and
the payload total length with <payload_total_len>.
2)+CMQTTRXTOPIC:
<client_index>,<sub_topic_len>\r\n<sub_topic>
“\r\n”.
and the command “+CMQTTRXTOPIC” will be send more than
is equal to <topic_total_len>.
3)+CMQTTRXPAYLOAD:
<client_index>,<sub_payload_len>\r\n<sub_payload>
module will send third message to user, and indicate client index
Smart Machine Smart Decision
After the command “+CMQT
For long topic, it will be split to multiple packets to report
After the comm
<sub_payload> after “\r\n”.
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 28 / 41
For long payload, the same as “+CMQTTRXTOPIC”.
4) +CMQTTRXEND: <client_index>
to <topic_total_len>.
<sub_topic>
<sub_payload_len>
packet length, The sum of
Defined Values
<client_index>
<topic_total_len>
<payload_total_len>
<sub_topic_len>
<sub_payload>
Smart Machine Smart Decision
indicate the topic and payload have been transmitted completely.
A numeric parameter that identifies a client. The range of permitted
values is 0 to 1.
The length of message topic received from MQTT server. The
range is from 1 to 1024 bytes.
The length of message body received from MQTT server. The
range is from 1 to 10240 bytes.
The sub topic packet length, The sum of <sub_topic_len> is equal
The sub topic content.
The sub message body
<sub_payload_len> is equal to <payload_total_len>.
The sub message body content.
3 Example
Before all MQTT related operations, we should ensure the following:
a) ensure GPRS network is available:
AT+CSQ
+CSQ: 23,0
OK
AT+CREG?
+CREG: 0,1
OK
AT+CGREG?
+CGREG: 0,1
OK
b) PDP context Enable:
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 29 / 41
Smart Machine Smart Decision
// Specify the parameter value of the PDP context corresponding to cid
AT+CGSOCKCONT=1,"IP","CMNET"
OK
AT+CGPADDR
+CGPADDR: 1,10.49.14.68 //ensure the first PDP context get a IP address
+CGPADDR: 4,0.0.0.0
OK
Note: usually CSOCKAUTH and CSOCKSETPN parameter are kept default if not care about.
3.1 Access to MQTT server not SSL/TLS
Following commands shows how to communicate with a MQTT server.
// start MQTT service, activate PDP context
AT+CMQTTSTART
OK
+CMQTTSTART: 0
// Acquire one client which will connect to a MQTT server not SSL/TLS
AT+CMQTTACCQ=0,”client test0”
OK
// Set the will topic for the CONNECT message
AT+CMQTTWILLTOPIC=0,10
>0123456789
OK
// Set the will message for the CONNECT message
AT+CMQTTWILLMSG=0,6,1
> qwerty
OK
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 30 / 41
// Connect to a MQTT server
AT+CMQTTCONNECT=0,"tcp://test.mosquitto.org:1883",60,1
OK
+CMQTTCONNECT: 0,0
// Subscribe one topic from the server
AT+CMQTTSUB=0,9,1
>simcommsg
OK
+CMQTTSUB: 0,0
// Set the topic for the PUBLISH message
AT+CMQTTTOPIC=0,9
> simcommsg
OK
// Set the payload for the PUBLISH message
AT+CMQTTPAYLOAD=0,60
> 012345678901234567890123456789012345678901234567890123456789
OK
// Publish a message
AT+CMQTTPUB=0,1,60
OK
+CMQTTPUB: 0,0
//receive publish message from server
+CMQTTRXSTART: 0,9,60
+CMQTTRXTOPIC: 0,9
simcommsg
+CMQTTRXPAYLOAD: 0,60
012345678901234567890123456789012345678901234567890123456789
+CMQTTRXEND: 0
// Set one topic for the SUBSCRIBE message
AT+CMQTTSUBTOPIC=0,9,1
>123456789
OK
// Subscribe a message
AT+CMQTTSUB=0
OK
+CMQTTSUB: 0,0
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SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 31 / 41
// Unsubscribe one topic from the server
+CMQTTSTOP: 0
AT+CMQTTUNSUB=0,9,0
>simcommsg
OK
+CMQTTUNSUB: 0,0
// Disconnect from server
AT+CMQTTDISC=0,120
OK
+CMQTTDISC: 0,0
//Release the client
AT+CMQTTREL=0
OK
//stop MQTT Service
AT+CMQTTSTOP
OK
Smart Machine Smart Decision
3.2 Connect to SSL/TLS MQTT server (not verify server)
Following commands shows how to access to a MQTT server without verifying the server. It needs to configure
the authentication mode to 0, and then it will connect to the server successfully.
// start MQTT service, activate PDP context
AT+CMQTTSTART
OK
+CMQTTSTART: 0
// Acquire one client which will connect to a SSL/TLS MQTT server
AT+CMQTTACCQ=0,”client test0”,1
OK
// Set the will topic for the CONNECT message
AT+CMQTTWILLTOPIC=0,10
>0123456789
OK
// Set the will message for the CONNECT message
AT+CMQTTWILLMSG=0,6,1
> qwerty
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 32 / 41
OK
// Connect to a MQTT server
AT+CMQTTCONNECT=0,"tcp://test.mosquitto.org:8883",60,1
OK
+CMQTTCONNECT: 0,0
// Set the topic for the PUBLISH message
AT+CMQTTTOPIC=0,13
> dddrrrggghhhk
OK
// Set the payload for the PUBLISH message
AT+CMQTTPAYLOAD=0,60
> 012345678901234567890123456789012345678901234567890123456789
OK
// Publish a message
AT+CMQTTPUB=0,1,60
OK
+CMQTTPUB: 0,0
// Set one topic for the SUBSCRIBE message
AT+CMQTTSUBTOPIC=0,9,1
>123456789
OK
// Subscribe a message
AT+CMQTTSUB=0
OK
+CMQTTSUB: 0,0
// Subscribe one topic from the server
AT+CMQTTSUB=0,9,1
>simcommsg
OK
+CMQTTSUB: 0,0
// Unsubscribe one topic from the server
AT+CMQTTUNSUB=0,9,0
>simcommsg
OK
+CMQTTUNSUB: 0,0
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SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 33 / 41
// Disconnect from server
+CMQTTSTOP: 0
OK
AT+CMQTTDISC=0,120
OK
+CMQTTDISC: 0,0
//Release the client
AT+CMQTTREL=0
OK
//stop MQTT Service
AT+CMQTTSTOP
OK
Smart Machine Smart Decision
3.3 Access to SSL/TLS MQTT server (only verify the server)
Following commands shows how to access to a SSL/TLS MQTT server with verifying the server. It needs to
configure the authentication mode to 1 and the right server root CA, and then it will connect to the server
successfully.
AT+CSSLCFG=”sslversion”,0,4// Set the SSL version of the first SSL context
OK
// Set the authentication mode(verify server) of the first SSL context
AT+CSSLCFG=”authmode”,0,1
OK
// Set the server root CA of the first SSL context
AT+CSSLCFG=”cacert”,0,”server_ca.pem”
OK
AT+CMQTTSTART // start MQTT service, activate PDP context
OK
+CMQTTSTART: 0
// Acquire one client which will connect to a SSL/TLS MQTT server
AT+CMQTTACCQ=0,”client test0”,1
OK
// Set the first SSL context to be used in the SSL connection
AT+CMQTTSSLCFG=0,0
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 34 / 41
// Set the will topic for the CONNECT message
AT+CMQTTWILLTOPIC=0,10
>0123456789
OK
// Set the will message for the CONNECT message
AT+CMQTTWILLMSG=0,6,1
> qwerty
OK
// Connect to a MQTT server, input the right server and port
AT+CMQTTCONNECT=0,"tcp://mqtts_server:port",60,1
OK
+CMQTTCONNECT: 0,0
// Set the topic for the PUBLISH message
AT+CMQTTTOPIC=0,13
> dddrrrggghhhk
OK
// Set the payload for the PUBLISH message
AT+CMQTTPAYLOAD=0,60
> 012345678901234567890123456789012345678901234567890123456789
OK
// Publish a message
AT+CMQTTPUB=0,1,60
OK
+CMQTTPUB: 0,0
// Set one topic for the SUBSCRIBE message
AT+CMQTTSUBTOPIC=0,9,1
>123456789
OK
// Subscribe a message
AT+CMQTTSUB=0
OK
+CMQTTSUB: 0,0
// Subscribe one topic from the server
AT+CMQTTSUB=0,9,1
>simcommsg
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SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 35 / 41
OK
+CMQTTSUB: 0,0
// Unsubscribe one topic from the server
AT+CMQTTUNSUB=0,9,0
>simcommsg
OK
+CMQTTUNSUB: 0,0
// Disconnect from server
AT+CMQTTDISC=0,120
OK
+CMQTTDISC: 0,0
//Release the client
AT+CMQTTREL=0
OK
//stop MQTT Service
AT+CMQTTSTOP
OK
Smart Machine Smart Decision
+CMQTTSTOP: 0
3.4 Access to SSL/TLS MQTT server (verify server and client)
Following commands shows how to access to a SSL/TLS MQTT server with verifying the server and client. It
needs to configure the authentication mode to 2, the right server root CA, the right client certificate and key, and
then it will connect to the server successfully.
// Set the SSL version of the first SSL context
AT+CSSLCFG=”sslversion”,0,4
OK
// Set the authentication mode(verify server and client) of the first SSL context
AT+CSSLCFG=”authmode”,0,2
OK
// Set the server root CA of the first SSL context
AT+CSSLCFG=”cacert”,0,”ca_cert.pem”
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 36 / 41
OK
// Set the client certificate of the first SSL context
AT+CSSLCFG=”clientcert”,0,”cert.pem”
OK
// Set the client key of the first SSL context
AT+CSSLCFG=”clientkey”,0,”key_cert.pem”
OK
// start MQTT service, activate PDP context
AT+CMQTTSTART
OK
+CMQTTSTART: 0
// Acquire one client which will connect to a SSL/TLS MQTT server
AT+CMQTTACCQ=0,”client test0”,1
OK
// Set the first SSL context to be used in the SSL connection
AT+CMQTTSSLCFG=0,0
OK
// Set the will topic for the CONNECT message
AT+CMQTTWILLTOPIC=0,10
>0123456789
OK
// Set the will message for the CONNECT message
AT+CMQTTWILLMSG=0,6,1
> qwerty
OK
// Connect to a MQTT server
AT+CMQTTCONNECT=0,"tcp://hooleeping.com:8883",60,1
OK
+CMQTTCONNECT: 0,0
// Set the topic for the PUBLISH message
AT+CMQTTTOPIC=0,13
> dddrrrggghhhk
OK
// Set the payload for the PUBLISH message
AT+CMQTTPAYLOAD=0,60
Smart Machine Smart Decision
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 37 / 41
> 012345678901234567890123456789012345678901234567890123456789
+CMQTTSTOP: 0
OK
// Publish a message
AT+CMQTTPUB=0,1,60
OK
+CMQTTPUB: 0,0
// Set one topic for the SUBSCRIBE message
AT+CMQTTSUBTOPIC=0,9,1
>123456789
OK
// Subscribe a message
AT+CMQTTSUB=0
OK
+CMQTTSUB: 0,0
// Subscribe one topic from the server
AT+CMQTTSUB=0,9,1
>simcommsg
OK
+CMQTTSUB: 0,0
// Unsubscribe one topic from the server
AT+CMQTTUNSUB=0,9,0
>simcommsg
OK
+CMQTTUNSUB: 0,0
// Disconnect from server
AT+CMQTTDISC=0,120
OK
+CMQTTDISC: 0,0
//Release the client
AT+CMQTTREL=0
OK
//stop MQTT Service
AT+CMQTTSTOP
OK
Smart Machine Smart Decision
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 38 / 41
Smart Machine Smart Decision
3.5 Access to MQTT server without checking UTF8 coding
Following commands shows how to communicate with a MQTT server without checking UTF8 coding.
// start MQTT service, activate PDP context
AT+CMQTTSTART
OK
+CMQTTSTART: 0
// Acquire one client which will connect to a MQTT server not SSL/TLS
AT+CMQTTACCQ=0,”client test0”
OK
// Configure not checking UTF8 coding
AT+CMQTTCFG=”checkUTF8”,0,0
OK
// Connect to a MQTT server
AT+CMQTTCONNECT=0,"tcp://test.mosquitto.org:1883",60,1
OK
+CMQTTCONNECT: 0,0
// Subscribe one topic which is not UTF8 coding string.
//The data can input by hexadecimal format.
AT+CMQTTSUB=0,9,1
>鼢鼢鼢鼢?
OK
+CMQTTSUB: 0,0
// Set the topic for the PUBLISH message
AT+CMQTTTOPIC=0,9
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 39 / 41
>鼢鼢鼢鼢?
鼢鼢鼢鼢
OK
// Publish a message
AT+CMQTTPUB=0,1,60
OK
+CMQTTPUB: 0,0
//receive publish message from server
+CMQTTRXSTART: 0,9,0
+CMQTTRXTOPIC: 0,9
Smart Machine Smart Decision
?
+CMQTTRXEND: 0
// Disconnect from server
AT+CMQTTDISC=0,120
OK
+CMQTTDISC: 0,0
//Release the client
AT+CMQTTREL=0
OK
//stop MQTT Service
AT+CMQTTSTOP
OK
+CMQTTSTOP: 0
SIM7500_SIM7600_SIM7800 Series_MQTT_AT Command Manual 40 / 41
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