SCADA

SCADA  Supervisory  Control  And  Data  Acquisition.

What is SCADA?

SCADA (supervisory control and data acquisition) is a category of software application program for process control, the gathering of data in real time from remote locations in order to control equipment and conditions. SCADA is used in power plants as well as in oil and gas refining, telecommunications, transportation, and water and waste control.

SCADA systems include hardware and software components. The hardware gathers and feeds data into a computer that has SCADA software installed. The computer then processes this data and presents it in a timely manner. SCADA also records and logs all events into a file stored on a hard disk or sends them to a printer. SCADA warns when conditions become hazardous by sounding alarms.                                                                                                           

SCADA systems were initially employed in the 1960s. They include both software and hardware components. The hardware collects and enters data into a computer with SCADA software. 

SCADA systems consist of:

• Field data interface equipment, generally programmable logic controllers (PLCs) or remote terminal units (RTUs). These connect to field sensing devices, local control switchboxes and valve actuators. Field-data-interface equipment forms the core part of SCADA systems.

• A communications system. This is employed to move data between different pieces of field data interface equipment and control units, and the computer systems employed in the SCADA central host. The system may be telephone, radio, satellite, cable, and so on, or a combination of any of these. The communications network is designed to offer the way by which the data can be transmitted in between the field-based RTUs and the central host computer servers.

• A central host computer server(s). This is often known as a master station, a SCADA center, or a master terminal unit (MTU). The central host computer is usually a single computer or a computer server network.

• A set of standard and/or customized software systems. They are helpful in delivering the operator terminal application and SCADA central host. This supports the communications system, and monitors and controls the remotely located field-data-interface equipment.

As such it is a software package that is purely positioned on top of hardware to which it is interfaced, in general via Programmable Logic Controllers (PLC), or other commercial hardware modules. 

SCADA systems are used not only in most industrial part processes: for example, steel making, power generation (conventional and nuclear) and distribution, chemistry, 

but also in some experimental facilities such as nuclear fusion. 

Main functions of the system SCADA

· Remote Monitoring Facilities 

· Remote Control Facilities 

· Information Processing 

· Presentation of Dynamic Graphics 

· Report Generation 

· Presentation of Alarms 

· Storage of Historical Information 

· Introducing Trend Charts 

· Schedule of Events

In conclusion a SCADA system is able to record data, generate alarms and manage a distributed control system through a network of hardware (usually PLCs and PACs).