The former is built upon [[:Category:SBC-AXEL|SBC-AXEL]] off-the-shelf board. It runs Android 6 (MarshmellowMarshmallow) and implements the high-level business logic besides the capacitive touch-screen based Man-Machine Interface (MMI). The latter integrates a bunch of application-specific I/O interfaces. The two boards are connected with an RS485 link on which data are exchanged through a proprietary protocol.

With regard to the gateway, on the legacy machine side, it acts as a traffic sniffer on the legacy machine side. It is connected to the RS485 link and it "eavesdrops" all the traffic flowing through this channel. As it is aware of the protocol used, it extracts each can parse the exchange packets and extract data from the packets exchangedthem. On the cloud side, the gateway uploads each to the NoSQL database every extracted piece of data along with an associated timestamp.

It is worth remembering that the '''extraction of data to be uploaded to the cloud is a non-intrusiveprocess''': '''neither no hardware nor /software modifications of the legacy machine were requiredfor the implementation of this solution'''.