Live Objects - complete developer guide

Data formats

Live Objects supports all data formats defined in the LwM2M v1.1 specification.

A client supporting LwM2M v1.0 must support TLV as stated in the LwM2M V1.0 specification (chapter 6.4). A client supporting LwM2M v1.1 must support Plain Text, Opaque, CoRE Link and at least one of SenML CBOR or SenML JSON.
If supporting optional data formats a LwM2M client may inform the server by including them in the Register operation.

When sending a Write Request or a Composite Request, Live Objects encodes the payload with a data format selected from those that are mandatory for the client and those that are declared as supported by the client (sent in the Register operation). The following rules apply:

Table 1. Request format (Write and Composite requests)
LwM2M version	request on a singular resource*	request on multiple resources*	composite request
v1.0	`Opaque` if declared as supported and the resource is of type opaque `TLV` otherwise	`TLV`	N/A
v1.1	`Opaque` if the resource is of type opaque `Plain Text` otherwise	`SenML CBOR` if declared as supported `SenML JSON` otherwise	`SenML CBOR` if declared as supported `SenML JSON` otherwise

The preferred response data format can be specified by Live Objects for Read, Observe, and their composite variants. If not specified, the client uses its own preferred format. The following rules apply:

Table 2. Preferred response format (Read, Observe and Composite requests)
LwM2M version	request on a singular resource*	request on multiple resources*	composite request
v1.0	not specified	not specified	N/A
v1.1	not specified	not specified	`SenML CBOR` if declared as supported `SenML JSON` otherwise

*Request on a singular resource: Request targeting a single Resource (ex: /3442/0/110) or a multiple Resource Instance (ex: /3442/0/1110/0).
*Request on multiple resources: Request targeting either an Object Instance (ex: /3442/0) or a multiple Resource (ex: /3442/0/1110).