SCADA

SCADA stands for the Supervisory Control and Data Acquisition. SCADA is a system which collects information from different sensors at a plant, factory or in some remote locations which then sends data to the central computer and then it controls and manages the data.

The term SCADA is broadly used to show the management and control solutions in many different industries. SCADA is used in a few industries like Electric Power, System for Mass Transit, Management Systems, Manufacturing Systems, Traffic Signals, System for Environment Control.

SCADA SYSTEM

The SCADA system has many parts for its working. The SCADA system mostly includes controllers, HMI (user interface), signal hardware (output and input), communications equipment, networks and software. On the whole this term SCADA is the complete central system. This central system monitors from various sensors all the data that are in close proximity or away from the site (sometimes kilometers away).

The RTU (Remote Terminal Units) performs the brains of the SCADA system for most of the part. The RTU (Remote Terminal Units) has a logic converter which is programmable. RTU are mostly set to certain specific requirements, but most RTU allows the human intervention, for example, in any factory setting RTU may control setting of the conveyer belt but the speed can change or can be overridden any time by human interference. Additionally any errors and changed are automatically displayed or logged for. Many times the SCADA systems are considered systems with closed loops and this system observe and make small changes for optimal function of the system. This system runs with very little intervention by humans.

Ability to scrutinize a complete system in actual time is one of the main processes of the SCADA. It is facilitated due to data acquisitions which include checking the statuses of the sensors, meter reading, etc which depending on system are communicated regularly in intervals. This data is used by RTU and is displayed to humans which then interfaces with system to make necessary changes or override settings.

SCADA consists of a lot of data elements called the points. Mostly these points are sensors or monitors. These points are either soft or hard. Actual monitors can be data points of hard types and software or application calculations are soft points. The data elements of soft and hard points are always logged and recorded to make a history or time stamp.

HMI (USER INTERFACE)

Human Machine Interface (HMI) is a user interface of the SCADA system. The data is presented and processed for being monitored and viewed by human operator in the Human Machine Interface of SCADA system. This interface includes all the controls where SCADA system can interface with the individuals.

These interfaces (HMI’s) are a way to normalize the facilitation to monitor many Programmable Logic Controllers (PLC’s) or RTU’s. Usually PLC’s or RTU’s run a process that has been pre programmed, but for them to monitored individually is very difficult, this is because all these are present all over the system. The PLC’s and RTU’s historically did not have any standard method to present data or display it to the operator, therefore PLC’s and SCADA system communicate with each other throughout the entire system network which then processes all the information which is then easily distributed by HMI.

HMI’s are also linked to databases, which use the data which is gathered from RTU’s or PLC’s to provide the required graphs on logistic info, schematics, trends for a precise machine or sensor or make the guides for troubleshooting accessible. In the previous decade, an integrated PLC and HMI device is included in all the SCADA systems making it very easy to monitor and run SCADA system.

SCADA HARDWARE AND SOFTWARE COMPONENTS

The SCADA systems monitor and run processes in a very advantageous way. These systems are good for very small applications like climate control and also be used effectively for large applications like controlling and monitoring nuclear power plant or system for mass transit.

SCADA comes in non proprietary and open protocols. Small systems are very affordable and are bought as a whole system or be matched and mixed with certain components. Off shelf components are used to create large systems. Software for SCADA system can be configured for any application, taking out the need for intensive or custom made software development.

BOOKS ABOUT SCADA

1. PRACTICAL MODERN SCADA PROTOCOLS:DNP3,60870.5 and RELATED SYSTEMS : Supervisory Control and Data Acquisition (SCADA) systems are the heart of today’s industrial enterprise from water, electric utility and mining plants installations to gas and oil plants. More practical data for engineers is needed in the market which is filled with high-level reference guides and monographs. This book tells all the essentials of communication system of the SCADA focusing on the DNP3, IEC 60870.5 standard with other developments in the given area. It starts with a very brief review regarding the fundamentals about the SCADA systems communications system (like RS-485, RS-232, TCP/IP and Ethernet), hardware and software that connects the Modules of SCADA together. A review is done on IEC 60870.5 and DNP3 protocols where all its message structures, practical benefits, features and its applications are discussed. It also provides us with all the knowledge required to design the next SCADA system even more efficiently using the latest technologies available for communication.
   1. It covers the essential details of communication system of the SCADA and the other developments of this area.
   2. It covers a very large range of the ideal topics for practicing technicians and engineers for further development of knowledge in their subject and also a large range of special networking topics.
   3. It is a very timely subject with a movement for the standard protocols has been made by the industry in the modern communication system of the SCADA system.

2. PRACTICAL SCADA FOR INDUSTRY : The SCADA system collects information

like where leak on a pipe has occurred, then transfer this information back to the

central site to alert the home station that a leak has taken place, to carry out all the

necessary control and analysis, like finding out whether the leak is crucial or not and

displaying this information in an organized and logical fashion. SCADA system is

relatively simple, like the one which keeps a check on the environmental conditions in a small office building or very complex, like a system which keeps a check on all the activities of a nuclear plant and also activity in the municipality water system.

1. Engineers introduction to SCADA systems with their applications in controlling and monitoring industrial plant and equipment.
2. Important reading for control professionals and data acquisitions in manufacturing, telecommunications, gas and oil refining, plant engineering, energy, transportation and waste and water control.
3. It gives all the knowledge to specify, debug, analyze and specify SCADA systems, hence covering all the fundamentals of software, communications system and hardware that connects all the SCADA operating stations.

3. SCADA:SUPERVISORY CONTROL AND DATA ACQUISITION : SCADA (Supervisory Control and Data Acquisition) technology has been evolving for the last 30 years as a way to control and monitor large processes. This completely revised reference guide which offers all the overviews of the SCADA component technologies, and all the necessary details to understand completely the entire picture. The SCADA process covers all the areas that can be measured in thousands of miles, and dimensions that are hundreds, or thousands, of kilometers long. SCADA now being a mature technology includes, not just limited to, all the software packages which can be added to a huge system. After reading its 14 self study units, all the readers should be well conversant with all the SCADA architecture and nomenclature, understand all the basic technologies involved in the building blocks of the system, understand all its limitations as well as understand how it benefits certain operations, and a standard for choosing the appropriate technologies of SCADA for all the operational requirements.

Additional Reading on SCADA Systems

• SCADA Systems

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