Changes

The legacy machine is powered by an embedded system that was designed by DAVE Embedded Systems years ago and that consists of several boards. Two of them are more relevant for the purposes of this discussion. They are named ''Single Board Computer'' and ''I/O board'' as shown in the following picture.

The two boards are connected with an RS485 link on which data are exchanged through a proprietary protocol.

The gateway is powered by an embedded Linux distribution, which was tailored for such applications. On the legacy machine side, the gateway acts as a traffic sniffer. It is connected to the RS485 link and eavesdrops all the traffic flowing through this channel. As it is aware of the protocol used, it can parse the exchanged packets and extract data from them. On the cloud side, the gateway uploads every extracted piece of data to the NoSQL database, along with an associated timestamp.

It is worth remembering that the '''extraction of data to be uploaded to the cloud is a non-intrusive process''': to implement this solution, '''no hardware/software modifications of the legacy machine were required'''.