Rack Devices are part of the Racks feature.
They are accessible using The Open-AudIT API.
...
Database Schema
The database schema can be found in the application is the user has database::read permission by going to menu → : Admin → -> Database → List Tables-> List Tables, then clicking on the details button for the table.
API / Web Access
You can access the collection using the normal Open-AudIT JSON based API. Just like any other collection. Please see The Open-AudIT API documentation for further details.