These functions are performed by four kinds of SCADA components:
Sensors (either digital or analog) and control relays that directly interface with the managed
Remote telemetry units (RTUs). These are small computerized units deployed in the field at
specific sites and locations. RTUs serve as local collection points for gathering reports from
sensors and delivering commands to control relays.
SCADA master units. These are larger computer consoles that serve as the central processor
for the SCADA system. Master units provide a human interface to the system and automatically
regulate the managed system in response to sensor inputs.
The communications network that connects the SCADA master unit to the RTUs in the field.