A substrate is electrically connected with an electrical device mounted on the substrate. The compressed air processing system includes an inlet connection, a pressure control unit, a multi-circuit protection valve, a plurality of outlet connections, a parking brake connection, an electronic control unit and a valve arrangement. The response includes data generated with an access key that is stored by both the mobile device and the locking device, and the user profile is encrypted by a server using a secret key that is stored by the server and the locking device. Each instant a bar code symbol is read within a predetermined time period, a symbol character data string representative of the read bar code symbol is automatically produced. A candidate priority can be automatically assigned to each test case selected to be included in the candidate test plan.