SCADA
SCADA (Supervisory Control And Data Acquisition) is a computer system designed to remotely monitor and control plants or equipment (refer to teleinformation and telecontrol) widely used in industries such as power distribution & transmission, water & waste control, oil & gas drilling as well as transportation. The system gathers information from the various plant equipment such as substations, pipeline and etc. using a variety of telecommunication technology – from cabled to wireless data transfer to the control centre for monitoring and control.
The SCADA system has differences in functionality and operating procedures as compared to PLC (Programmable Logic Control) and DCS (Distributed Control System). SCADA, as per its acronym, requires the operator to monitor and make decisions accordingly to operate each specific remote equipment by sending individual control commands one at a time. The control centre will receive feedback on whether the command has been executed successfully. This message is brought by the telecommunication protocol system, designed to satisfy the security and accuracy of received data and execution of commands via a telecommunication medium. This is in contrast to PLC and DCS, which are designed for process control that is dependent on the plant automation process software needed to execute the plant process automatically as per the PID (Proportional, Integral, and Derivative) programme. The controller will send updated information to the control centre regularly. No regular supervision is required unless the process parameters need to be changed. While the PLC & DCS system can cover more than one large plant in a wide area, it is normally situated in one location as compared to the SCADA system which can cover scattered areas located on different islands.
SCADA’s basic design consists of 4 main components such as Remote Terminal Unit (RTU), Communication Infrastructure (include Comms Server), SCADA Data Server, Human Machine Interface (HMI) or also widely known as Graphical User Interface (GUI) and many applications can be installed on top of basic system such as DMS & EMS for electrical utilities, GMS for gas utilities and many more applications can be added.