Introduction to SCADA

Introduction of SCADA, Architecture of SCADA, Software and hardware architecture, Components of a SCADA system, Functions of SCADA, Alarms and events, alarm logging, comparision between scada and DCS

1. SCADA Presented by, PRAVEENKUMAR S-15E137 1

2. Overview of SCADA A SCADA (Supervisory Control and Data Acquisition) is an industrial computer-based control system used to acquire the real-time data to keep track, monitor and control industrial equipments at the supervisory level. It is a combination of software, hardware and protocols. It is used in different types of industries and various domains. 2

3. Purpose of SCADA Ability to collect data & control process from distance. Ability to create logs on system’s current and past state Ability to send necessary information to operators in real time using SMS and internet. Reduces man-power needs Saves Energy, Time and Money Less traveling for workers Reliable Supervisory control over a particular system 3

4. Overall functions 4

5. DOMAINS Electrical generation, transmission & distribution Automation Railway and transportation Chemical storage and transportation 5

6. History Before the concept of SCADA, industrial plants and remote sites relied on personnel to manually control and monitor equipment via push buttons and analog dials. Industrial organizations started to utilize relays and timers to provide some level of supervisory control without having to send people to remote locations to interact with each device. 6

7. 4 Types of SCADA systems First Generation: Monolithic or Early SCADA systems(1950-70), Second Generation: Distributed SCADA systems(1980-90), Third Generation: Networked SCADA systems(1990-2000) and Fourth Generation: Internet of things technology, SCADA systems(2000) 7

8. Monolithic or Early SCADA Systems Minicomputers are used earlier for computing the SCADA systems. In earlier times, the common network services were not available. Hence, these are independent systems without having any connectivity to other systems. The functions in the early first generation were limited to monitoring sensors in the system and flagging any operations in case of surpassing programmed alarm levels. 8

9. Distributed SCADA Systems The sharing of control functions is distributed across the multiple systems connected to each other using Local Area Network (LAN). These individual stations were used to share real-time information for performing control tasks to trip the alarm levels of possible problems. The cost and size of the station were reduced compared to the first generation system, as each system of the second generation was responsible for performing a particular task with reduced size and cost. But even in the second generation systems also the network protocols were not standardized(proprietary). 9

10. GEN 2 VS GEN 3 10 The first and second generation SCADA systems are limited to single site networks called as sealed systems. In these systems, we can not have any risk compared to the third generation SCADA system which are connected to the internet causing the security risks. There will be several parallel working distributed SCADA systems under a single supervisor in network architecture.

11. Networked SCADA Systems The current SCADA systems are generally networked and communicate using Wide Area Network (WAN) Systems over mobile network, Ethernet or Fiber Optic Connections for transmitting data between the nodes frequently. These SCADA systems use Programmable Logic Controllers (PLC) for monitoring and adjusting the system parameters. Open system architecture and communication protocols 11

12. Architecture of SCADA Generally the SCADA system includes the following components: local processors, operating equipment, PLCs, instruments, RTU, intelligent electronic device, master terminal unit or host computers and a PC with human machine interface. Clint layer Data server layer 12

13. Hardware 13

14. Software architecture Most of the servers are used for multitasking and real time database. The servers are responsible for data gathering and handling. 14

15. SCADA Basics The block diagram of SCADA system 15

16. Human-machine Interface (HMI) It is an i -o device that presents the data to be controlled by a human operator. It is used by linking to the SCADA system’s software programs for providing the information, including the scheduled maintenance procedures, detailed schematics, trending and diagnostic data for a specific sensor or machine. HMI systems facilitate the operating personnel to see the information graphically. 16

17. Supervisory System Supervisory system is used as server for communicating between the equipment of the SCADA system such as RTUs, PLCs and sensors, etc., and the HMI software used in the control room workstations. Master station comprises a single PC in smaller SCADA systems and, in case of larger SCADA systems, it comprises distributed software applications, disaster recovery sites and multiple servers. 17

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19. Remote Terminal Units Physical objects in the SCADA systems are interfaced with the microprocessor controlled electronic devices called as Remote Terminal Units (RTUs). These units are used to transmit telemetry data to the supervisory system and receive the messages from the master system for controlling the connected objects. Data logging and alarm handling Asks the field devices for information Can control IEDs (Intelligent Electronic Device) Slave/Master device 19

20. Programmable Logic Controllers In SCADA systems, PLCs are connected to the sensors for collecting the sensor output signals in order to convert the sensor signals into digital data. PLCs are used instead of RTUs because of the advantages of PLCs like flexibility, configuration, versatile and affordability compared to RTUs. 20

21. Communication Infrastructure Generally the combination of radio and direct wired connections is used for SCADA systems, but in case of large systems like power stations and railways wireless network are frequently used. Private Network (LAN/RS-485) Internet Wireless Communication systems 21

22. Communication protocols MODBUS DNP 3.0 Fieldbus Controller Area Network (CAN) Profibus DirectNet TCP/IP Ethernet 22

23. SCADA Server It can be a Web server Data logging Analyzing data Serve the clients through a firewall Clients connected through internet Real-time decision maker Asks RTU for information 23

24. SCADA Programming SCADA programming in a master or HMI is used for creating graphs and diagrams which will give an important situational information in case of an event failure or process failure. SCADA programming can be done using derived programming language or C language 24

25. Event and alarm An alarm is an indication of an undesirable condition detected by the system such as a device that is not responding to input commands. The alarm alerts operators that this condition needs to be fixed. Event is a detectable occurrence which is of significance to the change of SCADA. 25

26. Monitoring and Event Processing 26

27. Alarm logging 27 Alarm logging  provides a straightforward process for creating and maintaining records to analyze the alarm state of equipment and processes.in your system.

28. Conclusion SCADA is a control system with More front end functionality More interfaces and efficient storage More record or device oriented configuration but System wide configuration tools are needed Less expensive than DCS, but offer different functionality than DCS And finally various applications 28

29. THANK YOU..!! 29