SCADA: What you need to know.
SCADA stands for Supervisory Control And Data Acquisition. In today’s world, SCADA looks after and controls the entire manufacturing process in real-time. It is a control system that comprises of computers, network infrastructures, GUI, PLCs and RTUs.
Furthermore, the system also comprises of HMI (Human Machine Interface) software. HMI processes the crucial data in real-time. It also analyzes and displays data in a human-readable format.
In addition, supervisory control and data acquisition architecture have microcomputers that connect with sensors and machinery on the factory floor. The data from the factory floor then flows to SCADA computers and software. The supervisory control and data acquisition software then processes, organizes and displays data to the factory managers and supervisors. As a result, the factory owners can make informed decisions, improving efficiency and productivity.
So, the SCADA is basically an automation tool that can process data and leverage its potential in real-time. It also helps managers and owners make decisions in real-time. It also has tremendous potential as current supervisory control and data acquisition systems are web-based and can be accessed all over the world.
Evolution of the supervisory control and data acquisition system
The first generation SCADA systems were monolithic in nature. These were independent systems and they didn’t have any connectivity with each other. These were proprietary systems.
The second-generation systems were distributed. This system had a LAN connection. The command system was distributed across multiple stations. It worked near real-time. However, these protocols were still propriety. This generation was more cost-effective than the previous generation.
Third-generation systems are networked. In this system, any complex SCADA system can be scaled down to simpler components that can be connected over a network via communication protocols. It consists of a LAN network called process control network (PCN). In this generation, the SCADA systems can run in parallel with only one supervisor. This is the most cost-effective solution for large scale operations.
The fourth-generation supervisory control and data acquisition system is web-based. It utilises various web technologies. So, it allows users to exchange information, view data and control processes from anywhere in the world. In these systems, browsers act as a GUI (Graphical User Interface) for particular HMI software. Hence it simplifies installation for manufacturers. In addition, it is very easier to access information as it needs the only browser which could be anywhere, on your laptop, mobile or tablet. This gives immense flexibility to the users.
Working of SCADA system
The SCADA system in general has four functional levels of manufacturing. However, the complex SCADA system can exist as it entirely depends on plant operations. The large manufacturing units such as Nuclear power plats and oil refinery plants will have complex supervisory control and data acquisition systems. These supervisory control and data acquisition systems may have different functional levels as the manufacturing process is increasingly complex.
The Level 0 functional level comprises of shop-floor devices like sensors, control elements, valves and actuators. These devices may vary from application to application. Field level elements may include starters as well.
Furthermore, level 1 consists of modules like PLCs (Programmable Logic Controllers) or RTUs (Remote Terminal Units). So, this level contains mainly distributed, electronic processors.
Level 2 contains computers that process incoming information from Level 1 modules. The data processed and displayed to the supervisor in such a way that the operator can take decisions and override if something goes out of hand.
In addition, Level 3 is a production-level control. This level does not directly control field processes. While it’s more of a monitoring level. This level also has more emphasis on targets.
The last level means Level 4 is a production scheduling level. In this level, managers set schedule for production taking into account many factors such as demand.
Advantages of supervisory control and data acquisition systems
The important advantage of these systems is its use. you can control industrial processes from remote locations or locally. In addition, you can acquire, process and present data in real-time. You can also control devices on the ground such as valves, actuators, pumps and motors. So, you have more and immediate control on production.
Furthermore, you can log events in near real-time. It brings more transparency overall. It also helps in finding errors and break downs. You can also eliminate downtime by accessing system log files. Thus, you can minimize the impact on production.
The web-based SCADA systems give you immense flexibility in terms of location and monitoring. So, you can control the pump on a remote oil rig in the Arctic ocean from your office in London. As a result, you have more granular control in the entire production process.
In addition, the use of these systems improves efficiency and output as you are in control all the time. Accurate data analysis is critical as it can save lots of money in the long term. Such efficiency is not possible in traditional manual control methods.
In conclusion, the SCADA systems can achieve high efficiency and output in any production process. We are very sure the new age systems gives lots of cost-benefit in long run.
Image Courtesy: Siemens
Watch the SCADA system in action:
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