EMQSUBOPEN – create a subscribe message topic

Create and view subscribe message topics. Use these topics to send data from the MQTT broker to your thing.

The topic name depends on the MQTT parameter unless you use a token. See Using the AnyNet SMARTconnect™ configuration file.

You can use the following tokens to construct the topic name:

• $t — Returns the cloud thingName.
• $i — Returns the device International Mobile Equipment Identity (IMEI).

For example, status/$i publishes as status/.

You can only include one token in a topic.

Type	Syntax	Returned result
Test	AT+EMQSUBOPEN=?	Available indexes, QoS values, and OK
Read	AT+EMQSUBOPEN?	A list of subscribe topics and OK
Write	AT+EMQSUBOPEN=(0-7),"/[$t | $i]"[,qos]	Creates or updates a subscribe topic

The Read command returns the index, unique topic name, and appended topicsuffix path. topicsuffix can include $i for the IMEI or $t for the cloud thingName. The complete topic must not exceed 256 characters. The Quectel module does not return empty topics.

For the Write command:

• Set the subscribe index from 0 through 7.
• Set a topic title up to 256 characters, including /cloudThingName or /IMEI.
• Do not use special characters in a topic title.
• Use topiclist to request the current topic list.
• Optionally set QoS to 0 for at-most-once delivery or 1 for at-least-once delivery.

Example

AT+EMQSUBOPEN=0,"SubscribeFromCloud0/$i,1"
OK
+EMQSUBOPEN: 0,0

AT+EMQSUBOPEN=1,"SubscribeFromCloud1"
OK
+EMQSUBOPEN: 1,0

AT+EMQSUBOPEN?
+EMQSUBOPEN:
0: SubscribeFromCloud0/862061040777777
1: SubscribeFromCloud1/cloudThingName
OK