[sblair]

Here's the basic steps related to sensor messages.

DEVICE_INFO message contains several basic parameters about the device, one of which is the number of sensors it includes. This and SUPPORTED_PARAMETERS are the first messages the controller requests.

The controller will also ask for SUPPORTED_PARAMETERS where the device will need to respond with SENSOR_DEFINITION and SENSOR_VALUE PIDs among those being supported by the device.

The controller will then send a request for the SENSOR_DEFINTION for each of the qty of sensors indicated from the DEVICE_INFO message to understand what type of sensor each is and what it is monitoring.

At this point the controller knows how many sensors there are and what each of the sensors does so it can then start sending SENSOR_VALUE messages for each of the sensors to get current readings.

Hope that helps.

Scott