Hi Roser,
The Information Model standardizes logical middleware interfaces between components (or we try to!). We are working on creating a modular interface assigning at least a basic message that covers the main objective of the device. For the other characteristics we use optional messages, so the user wil be able to work with the 100% of possibilities that the component offers.
We do this through H-ROS. H-ROS is the infrastructure for creating interoperable hardware and all that this entails, where, the Information Model is part of the infrastructure.