 Industrial Control System, Industrial Control System by CS is a general term that encompasses several types of control systems and associated instrumentation used for industrial process control. Such systems can range from a few modular panel-mounted controllers to large interconnected and interactive distributed control systems with many thousands of field connections. All systems received data received from remote sensors measuring process variables PBS compare these with desired set points SPS and derived command functions which are used to control the process through the final control elements FCEs such as control valves. Smaller larger systems are usually implemented by supervisory control and data acquisition SCADA systems, or distributed control systems TCS and programmable logic controllers PLCs though SCADA and PLC systems are scalable down to small systems with few control loops. Such systems are extensively used in industries such as chemical processing, pulp and paper manufacture, power generation, oil and gas processing and telecommunications.