Tiếng Anh kỹ thuật UNIT 2 SUPERVISORY CONTROL AND DATA ACQUISITION

UNIT 4 33 UNIT 2 SUPERVISORY CONTROL AND DATA ACQUISITION CONTENTS I Overview II System Concepts III Human Machine Interface IV System Components V Operational Philosophy VI Communication Infrastructu.

UNIT 2 SUPERVISORY CONTROL AND DATA ACQUISITION

CONTENTS

I Overview

II System Concepts

III Human Machine Interface

IV System Components

V Operational Philosophy

VI Communication Infrastructure and Methods

VII Future Trend in SCADA

VIII Security Issue

I OVERVIEW

I.1 READING

SCADA is the acronym for Supervisory Control And Data Acquisition In North

America and in the rest of the world, the term is used differently:

• In North America, SCADA refers to a large-scale, distributed measurement and control system

• In the rest of the world, SCADA is any system that performs Supervisory Control And Data Acquisition, independent of its size or geographical distribution

SCADA systems are typically used to perform data collection and control at the supervisory level Some SCADA systems only monitor without doing control, these systems are still referred to as SCADA systems

The supervisory control system is a system that is placed on top of a real-time control system to control a process that is external to the SCADA system (i.e a computer, by itself,

is not a SCADA system even though it controls its own power consumption and cooling) This implies that the system is not critical to control the process in real-time, as there is a separate or integrated real-time automated control system that can respond quickly enough to compensate for process changes within the time-constants of the process The process can be industrial, infrastructure or facility based as described below:

• Industrial processes include: manufacturing/production/power generation/fabrication /refining - continuous, batch, repetitive or discrete

• Infrastructure processes may be public or private and include: water treatment and distribution, wastewater collection and wastewater treatment, oil & gas pipelines, electrical power transmission and distribution and large communication systems

• Facility processes in private or public facilities including: buildings, airports, ships or space stations in order to monitor and control: HVAC (Heating, Ventilation, Air conditioning, and Cooling), access control, energy consumption management

I.2 VOCABULARY

Acquisition (n) [,ækwi'zi∫n]: Thu thập

Air conditioning (n) [eә kәn'di∫niη]: Điều hoà không khí

Collection (n) [kә'lek∫n]: Bộ sưu tập, tuyển tập

Compensate (v) ['kɔmpenseit]: Bù

Consumption (n) [kәn'sɔmp∫n]: Tiêu thụ, tiêu dùng

Critical (adj) ['kritikәl]: Quan trọng, trọng yếu

External (adj) [eks'tә:nl]: Bên ngoài

Facility (n) [fә'siliti]: Tiện nghi, cơ sở, chỗ

Geographical (adj) [dʒiә'græfikәl]: Địa lý

Integrated (adj) ['intigreitid']: Tích hợp

Infrastructure (n) [,infrә'strɔkt∫ә]: Cơ sở hạ tầng

Manufacturing (n) [mænju'fækt∫әriη]: (Discrete) Xản xuất (Lắp ráp)

Large-scale (adj) [lɔ:dʒ skeil]: Qui mô lớn

Power generation ['pauә dʒenә'rei∫n]: Xản xuất điện, phát điện

Power transmission ['pauә trænz'mi∫n]: Truyền tải điện

Power distribution ['pauә distri'bju:∫n]: Phân phối điện

Private (adj) ['praivit]: Tư nhân

Production (n) [prә'dɔk∫n]: (Batch, continous) Xản xuất

(bánh kẹo,vải, giấy …) Public (adj) ['pɔblik]: Công cộng

Fabrication (n) [,fæbri'kei∫n]: (Repetitive)Xản xuất

(gia công bằng tay: dệt may, đóng giày…)

Refining (n) [ri'fainiη]: Tinh chế, lọc

Repetitive (adj) [ri'petәtiv]: Lặp lại

Separate (adj) ['seprәt]: Riêng biệt

Supervisory (adj) ['su:pәvaizәri]: Giám sát

Time constant (n) [taim 'kɔnstәnt]: Hằng số thời gian

Treatment (n) ['tri:tmәnt]: Xử lý

Ventilation (n) [,venti'lei∫n]:: Thông gió

Water treatment (n) ['wɔ:tә 'tri:tmәnt]: Xử lý nước

Wastewater treatment (n) [weist wɔ:tә 'tri:tmәnt]: Xử lý nuớc thải

I.3 READING COMPREHENSION

Answer the following questions:

1 What does SCADA stand for?

2 How the term “SCADA” is understood differently in North America and the rest of the world?

3 What are the typical functions of SCADA systems?

4 What is the main function of SCADA system?

5 What kind of systems are the SCADA systems?

6 What features SCADA systems?

7 What are the processes for which SCADA systems are designed?

8 What are the industrial processes?

9 What can be an infrastructure process?

10 Where are the facility processes? And what are they?

II SYSTEM CONCEPTS

II.1 READING

A SCADA system includes input/output signal hardware, controllers, HMI (Human Machine Interface), networks, communication, database and software SCADA mainly comes in the branch of Instrumentation Engineering

The term SCADA usually refers to a central system that monitors and controls a complete site or a system spread out over a long distance (kilometers/miles) The bulk of the site control is actually performed automatically by a RTU (Remote Terminal Unit) or by a Programmable Logic Controller (PLC) Host control functions are almost always restricted

to basic site over-ride or supervisory level capability For example, a PLC may control the flow of cooling water through part of an industrial process, but the SCADA system may allow an operator to change the control set point for the flow, and will allow any alarm conditions such as loss of flow or high temperature to be recorded and displayed The feedback control loop is closed through the RTU or PLC; the SCADA system monitors the overall performance of that loop

Data acquisition begins at the RTU or PLC level and includes meter readings and equipment statuses that are communicated to SCADA as required Data is then compiled and formatted

in such a way that a control room operator using the HMI can make appropriate supervisory decisions that may be required to adjust or over-ride normal RTU (PLC) controls Data may also be collected in to a Historian, often built on a commodity Database Management System, to allow trending and other analytical work

SCADA systems typically implement a distributed database, commonly referred to as

a tag database, which contains data elements called tags or points A point represents a

single input or output value monitored or controlled by the system Points can be either

"hard" or "soft" A hard point is representative of an actual input or output connected to the system, while a soft point represents the result of logic and math operations applied to other hard and soft points Most implementations conceptually remove this distinction by making every property a "soft" point (expression) that can equal a single "hard" point in the simplest case Point values are normally stored as value-timestamp combinations; the value and the timestamp when the value was recorded or calculated A series of value-timestamp combinations is the history of that point It's also common to store additional metadata with tags such as: path to field device and PLC register, design time comments, and even alarming information

It is possible to purchase a SCADA system from suppliers It is more common to assemble a SCADA system from hardware and software components like Telvent, Allen-Bradley, ABB, Siemens, DirectLogic or GE PLCs, HMI packages from Adroit, Wonderware, Iconics, Rockwell Automation, Inductive Automation, Citect, or GE

II.2 VOCABULARY

Analytical (adj) [,ænә'litikәl]: Phân tích

Appropriate (adj) [ә'proupriәt]: Phù hợp, thích hợp

Communicate (v) [kә'mju:nikeit]: Truyền, chuyển

Conceptual (adj) [kәn'septjuәl]: Khái niệm

liệu Display (v) [dis'plei]: Biểu thị, trình bày

Historian (n) [his'tɔ:riәn]: Thiết bị lưu trữ

Metadata (n) [,metә' 'deitә]: Thông tin dữ liệu (data

that provides information about other data)

Meter reading (n) ['mi:tә 'ri:diη]: Số chỉ của thiết bị đo

Over-ride (v) ['ouvә raid]: Điều khiển thay, thay

thế

chung

Timestamp (n) [taim stæmp]: Thời điểm

II.3 READING COMPREHENSION

Answer the following questions:

1 What does a SCADA system include?

2 To what engineering branch does SCADA belong to?

3 What does SCADA refer to?

4 What does RTU stand for?

5 What is in charge of site control?

6 What are the host functions mainly restricted to?

7 In the cooling by water of an industrial plant, what a PLC may do and what

is the jobs of the SCADA system?

8 What do PLCs and RTUs do? What are the jobs of SCADA systems?

9 Where does data acqusition begin? And what does data acquisition invlove?

10 How can data be processed?

11 What does HMI enable human operators to do?

12 What is the base of Historians?

13 What allows for trending and analytical work?

14 What does SCADA system typically provide?

15 What does tag database contain?

16 What does a tag or a point represent?

17 What is a hard point? And what is a soft point?

18 The concept of hard points and soft points can be reduced to cover soft points only?

19 How point values normally stored?

20 What is the timestamp of a point value?

21 What is the purpose for value-timestamp combinations?

22 What can be the common metadata with tags?

23 How can we have SCADA systems?

III HUMAN MACHINE INTERFACE

III.1 READING

A Human Machine Interface or HMI is the apparatus which presents process data to a human operator, and through which the human operator controls the process

The HMI industry was essentially born out of a need for a standardized way to monitor and to control multiple remote controllers, PLC and other control devices While a PLC does provide automated, pre-programmed control over a process, they are usually distributed across a plant, making it difficult to gather data from them manually Historically PLCs had no standardized way to present information to an operator The SCADA system gathers information from the PLCs and other controllers via some form of network, and combines and formats the information An HMI may also be linked to a database, to provide trending, diagnostic data, and management information such as scheduled maintenance

procedures, logistic information, detailed schematics for a particular sensor or machine, and expert-system troubleshooting guides Since about 1998, virtually all major PLC manufacturers have offered integrated HMI/SCADA systems, many of them using open and non-proprietary communications protocols Numerous specialized third-party HMI/SCADA packages, offering built-in compatibility with most major PLCs, have also entered the market, allowing mechanical engineers, electrical engineers and technicians to configure HMIs themselves, without the need for a custom-made program written by a software developer

SCADA is popular, due to its compatibility and reliability It is used in small applications, like controlling the temperature of a room, to large applications, such as the control of nuclear power plants

III.2 VOCABULARY

Apparatus (n) [,æpә'reitәs]: Thiết bị, máy móc

Compatibility (n) [kәm,pætә'biliti]: Tính tương thích

Custom –made (adj) ['kɔstәm meid]: Làm theo đặt hàng

Detailed (adj) ['di:teild]: Cặn kẽ, tỉ mỉ

Diagnostic (adj) [,daiәg'nɔstik]: Chuẩn đoán

Expert (n) ['ekspә:t]: Chuyên gia

Essential (adj) [i'sen∫әl]: Chủ yếu, cốt yếu

Historical (adj) [his'tɔrikәl]: Lịch sử

Integrate (v) ['intigreit]: Tích hợp

Logistic (adj) [lou'dʒistik]: Hậu cần

Maintenance (n) ['meintinәns]: Bảo dưỡng

Non-proprietary (adj) [,nɔn prә'praiәtri]: Mở

Pre-programmed (adj) [,pri:' prougræmd]: Được lập trình sẵn

Reliability (n) [ri,laiә'bilәti]: Độ tin cậy

Standardize (v) ['stændәdaiz]: Chuẩn hoá

Third-party (n) [θә:d 'pɔ:ti]: Bên thứ ba

III.3 READING COMPREHENSION

Answer the following questions:

1 What does HMI stand for? And what is HMI?

2 That is the need that necessitates the development of HMI?

4 How can SCADA systems gather information from PLCs? And what they

do additionally?

5 What are the services HMI can provide? What enables HMI to do so?

6 What can major PLC manufacturers offer since 1998?

7 What enable mechanical engineers, electrical engineers, or technicians to configure HMI themselves?

8 What make SCADA popular?

9 What can be the scope of an SCADA application?

IV SYSTEM COMPONENTS

IV.1 READING

The three components of a SCADA system are:

1 Multiple Remote Terminal Units (also known as RTUs or Outstations)

2 Master Station and HMI Computer(s)

3 Communication infrastructure

Remote Terminal Unit (RTU)

The RTU connects to physical equipment, and reads status data such as the open/closed status from a switch or a valve, reads measurements such as pressure, flow, voltage or current By sending signals to equipment the RTU can control equipment, such as opening or closing a switch or a valve, or setting the speed of a pump The RTU can read digital status data or analogue measurement data, and send out digital commands or analogue set-points

The term RTU includes PLC "Smart" RTU or PLCs are the Distributed Control System (DCS) components of SCADA The use of DCS components which are capable of autonomously executing simple processes without involving the master computer, is increasing

An important part of most SCADA implementations are alarms An alarm is a digital status point that has either the value NORMAL or ALARM Alarms can be created in such a way that when their requirements are met, they are activated An example of an alarm is the

"fuel tank empty" light in a car The SCADA operator's attention is drawn to the part of the system requiring attention by the alarm Emails and text messages are often sent along with

an alarm activation alerting managers along with the SCADA operator

Master Station

The term "Master Station" refers to the servers and software responsible for communicating with the field equipment (RTUs, PLCs, etc), and then to the HMI software running on workstations in the control room, or elsewhere In smaller SCADA systems, the master station may be composed of a single PC In larger SCADA systems, the master station may include multiple servers, distributed software applications, and disaster recovery sites

The SCADA system usually presents the information to the operating personnel graphically, in the form of a mimic diagram This means that the operator can see a schematic representation of the plant being controlled For example, a picture of a pump

connected to a pipe can show the operator that the pump is running and how much fluid it is pumping through the pipe at the moment The operator can then switch the pump off The HMI software will show the flow rate of the fluid in the pipe decrease in real time Mimic diagrams may consist of line graphics and schematic symbols to represent process elements,

or may consist of digital photographs of the process equipment overlain with animated symbols

The HMI package for the SCADA system typically includes a drawing program that the operators or system maintenance personnel use to change the way these points are represented in the interface These representations can be as simple as an on-screen traffic light, which represents the state of an actual traffic light in the field, or as complex as a multi-projector display representing the position of all of the elevators in a skyscraper or all

of the trains on a railway Initially, more "open" platforms such as Linus were not as widely used due to the highly dynamic development environment and because a SCADA customer that was able to afford the field hardware and devices to be controlled could usually also purchase UNIX or Open VMS licenses Today, all major operating systems are used for both master station servers and HMI workstations

IV.2 VOCABULARY

Activate (v) ['æktiveit]: Kích hoạt

Animated (adj) ['ænimeitid]: Hoạt hoá

Autonomously (adv) [ɔ:'tɔnәmәsli]: Độc lập

Component (n) [kәm'pounәnt]: Bộ phận cấu thành

Dynamic (adj) [dai'næmik]: Chức năng

Elsewhere (adv) ['els'weә]: Chỗ khác, nơi khác

Enhance (v) [in'hɔ:ns]: Tăng cường, củng cố

Large-scale (adj) [lɔ:dʒ skeil]: Qui mô lớn

Mimic (adj) ['mimik]: Mô phỏng

Overlain with (adj) [,ouvә'lain wiđ]: Kèm với

Railway (n) ['reilwei]: Đường tầu

Responsible (adj) [ri'spɔnsәbl]: Trách nhiệm, chịu trách nhiệm

Valve (n) [vælv]: Van

IV.3 READING COMPREHENSION

Answer the following questions:

1 What are the three components of SCADA?

2 What does RTU stand for?

3 What are the tasks of RTUs?

4 Generally, what a RTU can do?

5 Is a PLC a RTU?

6 What type of components of SCADA are the RTUs or PLCs?

7 What is on increase in the design of SCADA systems?

9 What is an important part of most SCADA implementations?

10 How can we define an alarm?

11 In what way are alarms created?

12 What can be an example of alarms?

13 What is the purpose of alarms?

14 What can happen together with alarm activation?

15 What does the term “Master Station” refer to?

16 What can be the possible configuration of Master station?

17 In what form do SCADA systems present information to the operating personnel?

19 What can an operator see?

20 What may mimic diagrams consist?

21 What do HMI packages for SCADA systems typically include?

22 What can be the represented in mimic diagrams?

23 Why initially Linus was not widely used as the operating system for SCADA application?

24 Nowadays, can major operating systems be used with Master station servers and HMI workstations?

V OPERATINAL PHILOSOPHY

V.1 READING

Instead of relying on operator intervention, or master station automation, RTUs may now be required to operate on their own to control or perform other safety-related tasks The master station software is required to do more analysis of data before presenting it to operators including historical analysis and analysis associated with particular industry requirements Safety requirements are now being applied to the system as a whole and even master station software must meet stringent safety standards for some markets

For some installations, the costs that would result from the control system failing is extremely high Possibly even lives could be lost Hardware for SCADA systems is generally hardened to withstand temperature, vibration, and voltage extremes, but in these