The list of cluster attribute ID. We reuse the LibertasClusterReadReq structure to hold required data. Note that the event field is always undefined because the Libertas OS will handle the event reports.
The Thing-App engine is responsible for each subscription reporting, based on the subscribed attributes, events, and min/max intervals. Event if the virtual device reported the changes, the report may not be generated immediately if the minimum interval has not been reached. Also when the Libertas Thing-App engine decides to generate a report, it will send a LibertasDeviceAction.ReadRequest or LibertasDeviceAction.SubscribeRequest with an array of LibertasClusterReadReq for the up-to-date values of the specified attributes and expect a response from Libertas_VirtualDeviceAttributesRsp call.
Notify the Libertas Thing-App engine that some attributes has changed vaklues.