Anyone who wants to know facts about SCADA systems should first learn what the initials stand for, and it is supervisory control and data acquisition. Basically SCADA points to industrial control systems (ICS) that is utilized for managing infrastructure processes. The processes that comprise the system are wind farms, gas pipelines and water treatments among others.
The system also encompasses industrial processes like power generation, manufacturing, and production as well as facility based processes like ships, space stations, airports and more. All SCADA systems have the following subsystems and components. The first is the device used by the operator and it is used to process data.
It will also have a supervisory system to collect all the data and it will also have Remote Terminal Units (RTUs) that are linked to the process sensors. This is used for sensor signal conversion and transmitting the information to the steam.
These systems also have PLCs (Programmable Logic Controller) and are utilized as field devices, and it also has a communication infrastructure that will link supervisory system to the Remote terminal Unit. Usually, SCADA systems do not offer real time process control. However, it can refer to the system that handles the process.
SCADA points to the centralized systems that monitor and manage a whole site, and it can also refer to intricate systems that are laid out in numerous areas. Almost all the control actions are done automatically using the RTUs or via PLCs.
The limitations on the host control functions are at either basic override or supervisory level intervention. For instance, the PLC will manage cooling systems and the SCADA permits changes to be made that is connected to the set points and alarm conditions that will be displayed.
Gathering of data starts at the RTU or PLC level and this includes meter readings, equipment status reports and more. The information is then transmitted so that the control room operator can rapidly make decisions whether to adjust the RTU or PLC controls by utilizing the HMI.
These systems typically put in place the tag databases, each holding tags and points. Each point has one input or output value that the system monitors. These points may be either hard or soft. The system input or output is symbolic of a hard point while the soft point is the product of various logic and mathematical operations that is placed on different points. All of these points are kept as timestamp-value pairs.
The Human Machine Interface (HMI) is a device that gives a human operator access to data. Basically, the HMI is what a human operator will use to manage the process. HMI is connected to the database of a SCADA system. With it, you have the means to perform diagnosis trend and manage data. HMI also helps the operator gather info concerning schematics and logistics. The data provided here can also be used for maintenance or troubleshooting.
When you study facts about SCADA systems you will learn that the HMI system displays the info in a graphical manner so it is easier to comprehend. So if you are the operator the system will display the plant that is currently under your control. Software is built into HMI that allows you to increase or decrease the fluid flow rate.