What is SCADA?
As an acronym for Supervisory Control and Data Acquisition, SCADA is a concept that is used to refer to the management and procurement of data that can be used in developing process management criteria. The use of the term SCADA varies, depending on location. In North America, SCADA refers to a distributed measurement and management system that operates on a large-scale basis. For the rest of the world, SCADA refers to a system that performs the same basic functions, but operates in a number of different environments as well as a multiplicity of scales. While the use of the term SCADA may not be uniform, many components are the same, regardless of the scale of the process. Data collection and control of that data is essential to any SCADA process. Along with the task of acquiring the data, there also has to be a means of managing the data. It is this supervisory component that helps to make sense of the collected data and allow for its application in a number of different ways. A sound
SCADA stands for Supervisory Control and Data Acquisition but it is a term often used for data collection and presentation. SCADA is normally a software package designed to display information, log data and show alarms. This can be graphical and tabular and can involve words and pictures (or mimics). The software would normally be installed on a computer on the customers site and all the various signals would be wired back to the central point, or marshalled and gathered using some form of bus system. SCADA can be used to monitor and control plant or equipment. The control may be automatic, or initiated by operator commands. The data acquisition is accomplished firstly by the RTU’s (remote Terminal Units, in our case the IN4MA) The central host will scan the RTU’s or the RTU’s will report in Data can be of three main types. Analogue data (i.e. real numbers) will be trended (ie placed in graphs). Digital data (on/off) may have alarms attached to one state or the other. Pulse data (e.g.
It is used to monitor and control plant or equipment. The control may be automatic, or initiated by operator commands. The data acquisition is accomplished firstly by the RTU’s scanning the field inputs connected to the RTU (it may be also called a PLC – programmable logic controller). This is usually at a fast rate. The central host will scan the RTU’s (usually at a slower rate.) The data is processed to detect alarm conditions, and if an alarm is present, it will be displayed on special alarm lists. Data can be of three main types. Analogue data (ie real numbers) will be trended (ie placed in graphs). Digital data (on/off) may have alarms attached to one state or the other. Pulse data (eg counting revolutions of a meter) is normally accumulated or counted. The primary interface to the operator is a graphical display (mimic) which shows a representation of the plant or equipment in graphical form. Live data is shown as graphical shapes (foreground) over a static background. As the dat
