of industrial computer control system that can monitor and control
large scale industrial processes that include multiple sites, and large distances. A SCADA system usually consists of the following subsystems:
- A human–machine interface (HMI) is device which presents process data to a human operator, and thus enabling the human operator monitors and controls the process.
- A supervisory computer system, acquiring data on the process and sending control commands to the process.
- Remote terminal units (RTUs) connecting to sensors in the process, converting sensor signals to digital data and sending digital data to the supervisory system.
- Programmable logic controller (PLCs) used as field devices because they are more flexible than special-purpose RTUs.
- Communication infrastructure connecting the supervisory system to the remote terminal units.
by Denis Simukov
Source: Christian Bergan, “Enhancing Oil And Gas Operations – SCADA via Satellite”, 2015