One of the main functions of a SCADA system is the data acquisition system. This acts as a natural data concentrator, collecting the data from different field devices, micro-controllers, and PLCs that control the different working lines or functional areas of the factory. From the perspective of I-IoT data acquisition, SCADA systems are very similar to the DCS; they are organized hierarchically, there are few of them, and they are typically supplied by the same vendor. For example, in a medium-sized manufacturing plant, you might have one or two SCADA systems supervising the whole plant, plus some local HMI monitoring working in cells or small areas. Since SCADA adopts a common approach to processing industrial data that is often based on a common data model, it is easier to identity and recognize the data stream needed by the I-IoT data stream. They may need to communicate with MES and ERP systems so they are usually already linked to the plant or corporate network. This simplifies the task of transferring data to the cloud over the internet.