EMQPERSIST – report a set value to the device shadow

Report a set value to the device shadow/twin. The operation depends on which AWSSHADOW mode you set, either simple or complete.

You set AWSSHADOW in the Configuration File. For more information, see Using the Cinterion® PLS62‑W Wireless Module configuration file.

AWSSHADOW simple mode

The shadow ETM performs the following automatically:

  • Generates the JSONstate and reported or desired objects
  • Subscribes to the shadow/update/delta topic, and filters out the containing objects
  • Presents the host with the state object JSON content only, sent via URC

The host only sends the content of the reported object.

AWSSHADOW complete mode

The host sends the complete JSON for the shadow to ETM.

ETM sends the complete shadow message as a URC, without filtering.

EMQPERSIST commands

Type Syntax Returned Result
Test

AT+EMQPERSIST=?

OK

 

EMQPERSIST:<json>
Read

AT+EMQPERSIST?

OK

or

ERROR
Write

AT+EMQPERSIST=<JSON>

where JSON is the JSON code, which depends on the AWSSHADOW mode you configured.

For simple mode:

Either the content of the statereported object or desired object is required, in this format:

AT+EMQPERSIST="{\"key\":value}"

where value is a numeric value, including decimals and negative numbers.

If the passed-in text does not include reported or desired, then reported is assumed. The state reported encapsulation is appended.

If the passed-in text includes reported and/or desired, only the state encapsulation is appended.

For example, for the reported text:

"{\"key\":\"value\"}" and

"{\"reported\":{\"key\":\"value\"}}" are both sent as

{\"state\":{\"reported\":{\"key\":\"value\"}}}

For example, for reported and desired text:

"{\"reported\":{\"key\":\"value\"},\"desired\":{\"key\":\"value\"}}" is sent as

{\"state\":{\"reported\":{\"key\":\"value\"},\"desired\":{\"key\":\"value\"}}}.

For complete mode:

The complete JSON data for the shadow/update topic is required, in this format:

AT+EMQPERSIST="{\"state\":{\"reported\":{\"key\":value}}}"

where value is a numeric value, including decimals and negative numbers.

 

OK

 

SEND OK

or

ERROR

Examples

For Simple mode:

AT+EMQPERSIST="{\"Temperature\":-3.5}"

AT+EMQPERSIST="{\"Colour\":\"Blue\"}"

For Complete mode, including setting AWSSHADOW to complete:

AT+EMQPERSIST="{\"state\":{\"reported\":{\"Temperature\":28.0}}}"

Where to next?

Related resources