Ethiopian TVET-System
Transcript of Ethiopian TVET-System
Ethiopian TVET-System
Electro Mechanical Equipment Operation and Maintenance
NTQF Level -IV
Module Title: Using and Facilitating the Use of
System Control and Data Acquisition (SCADA)
TTLM Code: EIS EME4TTLM0920 v1
Electro-Mechanical Equipment Operation and
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This module includes the following Learning Guides
LG59: Identify scope of SCADA system
LG Code: EIS EME4 M13 LO1-LG 59
LG 60: Communicate using SCADA system
LG Code: EIS EME4 M13 LO2-LG-60
LG 61: Make decisions using SCADA
LG Code: EIS EME4 M13 LO3-LG-61
LG 62: Support team use of SCADA
LG Code: EIS EME4 M13 LO2-LG-62
LG 63: Monitor the use of SCADA
LG Code: EIS EME4 M13 LO3-LG-63
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Instruction Sheet 1 Learning Guide 64: Identify scope of SCADA system
This learning guide is developed to provide you the necessary information regarding the following
content coverage and topics
Identifying categories of information held in and control options of SCADA system
Identifying range of information able to be provided to SCADA system by team
Identifying range of information able to be provided to team by SCADA system
Identifying team or area functions impacted by SCADA system
This guide will also assist you to attain the learning outcome stated in the cover page. Specifically, upon
completion of this Learning Guide, you will be able to
Identify categories of information held in and control options of SCADA system
Identify range of information able to be provided to SCADA system by team
Identify range of information able to be provided to team by SCADA system
Identify team or area functions impacted by SCADA system
Learning Instructions:
1. Read the specific objectives of this Learning Guide.
2. Follow the instructions described in number 3 to 14.
3. Read the information written in the “Information Sheets 1”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
4. Accomplish the “Self-check 1” .
5. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 1).
6. If you earned a satisfactory evaluation proceed to “Information Sheet 2”. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to Learning Activity #1
7. Submit your accomplished Self-check. This will form part of your training portfolio.
8. Read the information written in the “Information Sheet 2”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
9. Accomplish the “Self-check 2” .
10. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 2).
11. Read the information written in the “Information Sheets 3 and 4”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
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12. Accomplish the “Self-check 3”
13. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 3).
14. If you earned a satisfactory valuation, proceed to “Operation Sheet 1”. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to for each Learning Act
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1.1 Introduction.
SCADA stands for “Supervisory Control and Data Acquisition”. SCADA is a type of process control system architecture that uses computers, networked data communications and graphical Human Machine Interfaces (HMIs) to enable a high-level process supervisory management and control. SCADA systems communicate with other devices such as programmable logic controllers (PLCs) and PID controllers to interact with industrial process plant and equipment. SCADA systems form a large part of control systems engineering. SCADA systems gather pieces of information and data from a process that is analyzed in real-time (the “DA” in SCADA). It records and logs the data, as well as representing the collected data on various HMIs. This enables process control operators to supervise (the “S” in SCADA) what is going on in the field, even from a distant location. It also enables operators to control (the “C” in SCADA) these processes by interacting with the HMI.
Fig.11.1Ge
neric SCADA System
SCADA systems are essential to a wide range of industries and are broadly used for the controlling and monitoring of a process. SCADA systems are prominently used as they have the power to control, monitor, and transmit data in a smart and seamless way. In today’s data-driven world, we are always looking for ways to increase automation and make smarter decisions through the proper use of data – and SCADA systems are a great way of achieving this.
SCADA systems can be run virtually, which allows the operator to keep a track of the entire process from his place or control room. Time can be saved by using SCADA efficiently. One such excellent example is, SCADA systems are used extensively in the Oil and Gas sector. Large pipelines will be used to transfer oil and chemicals inside the manufacturing unit. Hence, safety plays a crucial role, such that there should not be any leakage along the pipeline. In case, if some leakage occurs, a SCADA system is used to identify the leakage. It infers the information, transmits it to the system, displays the information on the computer screen and also gives an alert to the operator.
Information Sheet-1 Identifying categories of information held in and control
options of SCADA system
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fig.2 SCADA Architecture
Generic SCADA systems contain both hardware and software components. The computer used for analysis should be loaded with SCADA software. The hardware component receives the input data and feds it into the system for further analysis. SCADA system contains a hard disk, which records and stores the data into a file, after which it is printed as when needed by the human operator. SCADA systems are used in various industries and manufacturing units like Energy, Food and Beverage, Oil and Gas, Power, Water, and Waste Management units and many more.
1.2 Objectives of SCADA
I Monitor: SCADA systems continuously monitor the physical parameters II Measure: It measures the parameter for processing III Data Acquisition: It acquires data from RTU, data loggers, etc IV Data Communication: It helps to communicate and transmit a large amount of data
between MTU and RTU units V Controlling: Online real-time monitoring and controlling of the process VI Automation: It helps for automatic transmission and functionality
The SCADA systems consist of hardware units and software units. SCADA applications are run using a server. Desktop computers and screens act as an HMI which are connected to the server. The major components of a SCADA system include:
Master Terminal Unit (MTU) Remote Terminal Unit (RTU) Communication Network (defined by its network topology)
Master Terminal Unit (MTU) MTU is the core of the SCADA system. It comprises a computer, PLC and a network server that helps MTU to communicate with the RTUs. MTU begins communication, collects and saves data, helps to interface with operators and to communicate data to other systems.
Communication Network In general, network means connection. When you tell a communication network, it is defined as a link between RTU in the field to MTU in the central location. The bidirectional wired or wireless communication channel is used for networking purposes. Various other communication mediums like fiber optic cables, twisted pair cables, etc. are also used.
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Fig.1.3 Functional Units of SCADA
Remote Terminal Unit (RTU)
Being employed in the field sites, each Remote Terminal Unit (RTU) is connected with sensors and actuators. RTU is used to collect information from these sensors and further sends the data to MTU. RTUs have the storage capacity facility. So, it stores the data and transmits the data when MTU sends the corresponding command. Recently developed units are employed with sophisticated systems, that utilize PLCs as RTUs. This helps for direct transfer and control of data without any signal from MTU.
Fig.1.4 Remote terminal unit
Human interface – HMI machine (Human – Machine Interface): is the device that displays the data processing process for the operator to control the operation process of the system.
1.3 Functions of SCADA Systems In a nutshell, we can tell the SCADA system is a collection of hardware and software components that allows the manufacturing units to perform specific functions. Some of the important functions include
To monitor and gather data in real-time To interact with field devices and control stations via Human Machine Interface (HMI) To record systems events into a log file To control manufacturing process virtually Information Storage and Reports
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1.4 SCADA Applications SCADA has made comprehensive use of features such as flexibility, reliability, and scalability in automating complex systems. There are countless applications in the real world where SCADA has already been effective in providing surveillance and control alternatives across a broad spectrum of sectors, from energy production to agricultural systems. SCADA is widely used in different areas from chemical, gas, water, communications and power systems
Electric Power Generation, Transmission, and Distribution
Using SCADA systems, electrical utilities detect current flow and line voltage, monitor circuit breaker operation, and take sections of the power grid online or offline.
Manufacturing Units
SCADA systems are used to regulate industrial automation and robots, and monitor process and quality control
Mass transit and Railway Traction
Transit officials use SCADA to regulate electricity for subways, trams and trolley busses; to automate railway traffic signals; to monitor and identify trains and busses, and to control railway crossing doors
Water, Waste Water Utilities and Sewage
State and municipal water utilities use SCADA to monitor and control water flow, tank concentrations, pipe pressure, and other variables
Fig 1.5 SCADA Applications in Water Pump Station
Buildings, Facilities, and Environments Facility managers use SCADA to regulate HVAC, cooling, lighting and input systems.
1.5 Water Security: The Role of the SCADA System A lot of research continues to be performed on how to implement modern SCADA concepts into water treatment plants whilst minimizing the risk of unauthorized network access (cyber risk is an ongoing issue in large enterprises). The communication network of SCADA is distributed across the water distribution system as shown in the figure below. Workstations,
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typically PC-based are situated at a treatment facility in a control room, enable operators to view the entire process and take control measures. Within the plant, PLCs are used in chemical treatment and filters. Local Area Network (LAN) is utilized to link the controllers to workstations. Remote terminal units (RTUs) are used in remote locations and are generally found in sensitive fields such as pump stations, storage tanks, valve vaults, and treatment centers. The RTU communicates on a wide area network typified by the radio scheme shown in the following figure. A significant benefit of SCADA schemes is the coordination of safety measures with activities. A SCADA system connected to perimeter surveillance systems can either decrease the need for manned patrols considerably or eliminate them.
Fig 1.6 SCADA Applications in Water Treatment Plant
The SCADA scheme can provide ongoing surveillance of all places, unlike patrols. You can easily interface security systems or appliances, including video cameras, motion detectors, contact switches, keypad entry devices, and card readers, either directly to the SCADA network or via a neighboring remote terminal unit (RTU). Today’s SCADA systems also give alarm management in instances where many alarms happen in a brief moment.
Supervisory Control and Data Acquisition (SCADA) and Human Machine Interface (HMI) are closely related, and often referred to in the same context since they are both parts of a larger industrial control system, but they each offer different functionality and opportunities.
While HMIs are focused on visually conveying information to help the user supervise an industrial process, SCADA systems have a greater capacity for data collection and control system operation.
1.6 SCADA control options
Push buttons and switches. Programmable controllers.
I/O modules.
Operator interfaces.
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Development software packages.
Industrialized computers.
Specialized PLC-based hardware and software that support process control, motion control, and AC/DC drives.
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Self-Check -1 Written Test
Direction I: Choose the best answer to the following questions. Use the Answer sheet
provided in the next page:
1. A ___________consists of high speed, unidirectional digital communication channel (e.g. fiber optics link, twisted-wire pair, etc.) which’s arranged as a closed loop or ring microcomputers are attached to the ring by ring interface units. A) Shared bus systems B) Ring system C) Hierarchical system D) All the Answers
2. A SCADA system performs Data acquisition, Networked data communication, _________ and Control. Data representation 3. Sensors and control relays can’t generate or interpret protocol communication, _______ is needed to provide an interface between the sensors and the SCADA network. A) Remote Terminal Units (RTUs) B) HMI C) Field Instruments D) All of the Answers
4. A central host computer server or servers called ________ A) Switch B) Master Terminal Units (MTUs) C) Junction Box D) Microcontroller
5. A collection of standard and/or custom software systems used to provide the SCADA central host and operator terminal application, support the communications system, and monitor and control remotely located field data interface devices called as ______ A) HART Protocol B) Human Machine Interface (HMI) C) Input Output Modules D) Network Gateway
6. Combine communications paths to and from many RTUs into a single bit stream, usually using time division multiplexing (TDM) or other such bit stream manipulation techniques. A) Human Machine Interface (HMI) B) Multiplexers C) Barrier D) PLC
7. SCADA systems encompass the transfer of data between a central host computer and a number of ______________and/or Programmable Logic Controllers (PLCs), and the central host and the operator terminals.
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A) Microcontrollers B) Remote Terminal Units (RTUs) C) Input Output Modules D) Motor Control Center
8. _______ may employ one or more workstations and can be configured at the workstation or by an off-line personal computer. A)RTU B)Router C)DCS D) Gate Way
9. A _________ consists of number of minicomputers or microcomputers inter connected in a tree structure. A) Ring system B) Hierarchical system C) Shared bus systems D) All the Answers
10. In __________the-connected processors communicated over a common channel using time-sharing, thus allowing attached computers to transmit information in short-duration, high speed bursts. A) Ring system B) Hierarchical system C) Shared bus systems D) All the Answers
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
Rating: ____________
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2.1 Introduction
As illustrated in figure 1 below, the controlled process/ plant is notionally partitioned for the purpose of monitoring and control into certain sections. A small microprocessor-based unit, called remote terminal unit or RTU, is placed in and interfaced to each section of the plant. There is a large computer-based central supervisory unit, or the control and monitoring unit, called master terminal unit (MTU) or master station or supervisory station. It is located in a central or strategic place, called control room. Each RTU is expected to acquire data (analog values of controlled and uncontrolled variables and status information of remote and locally controlled objects) from the plant section assigned to this particular RTU and to transmit data to the MTU after necessary processing of the acquired data. Likewise, each RTU expects to receive control instructions (relevant to the plant section assigned to it) from the MTU and deliver them to the plant. This two-way digital communication between RTUs and MTU is carried out on the socalled MTU-RTU communication sub-system.
The RTU acquires analog values and status information from analog and status sensors, respectively. Similarly, it delivers the set points and discrete control commands to automatic controllers and actuators, respectively. These devices thus act as the interface between the RTU and the controlled plant. Being located in the field (within the plant), these devices are known as field devices (FDs). The electrical communication system linking the field devices to the RTU is called the RTU-FD communication sub-system. Thus, a SCADA system is broadly comprised of the following five components:
(i) Remote terminal units (RTUs)
(ii) Master terminal unit (MTU)
(iii) MTU-RTU communication subsystem
(iv) Field devices (FDs)
(v) RTU-FD communication subsystem.
Fig 2.1 Modified layout of SCADA system (D: Data, C: Control instruction/signal)
Information Sheet-2 Identifying range of information able to be provided to
SCADA system by team
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2.2 Supervisory control and data acquisition (SCADA) system Functions
A supervisory control and data acquisition (SCADA) system performs the following
major functions:
(i) Human-machine interface (HMI)
(ii) Electrical communication
(iii) Data acquisition (DAQ) and Transmission
(iv) Monitoring
(v) Control
(vi) Data collection, storage and retrieval
(vii) Calculation
(viii) Report generation
Various functions of SCADA system are now described one-by-one in detail in the
following sections.
2.2.1 Human-Machine Interface (HMI) The SCADA system is designed to monitor and control the process/ plant
automatically most of the time. However, for various reasons provisions are made for
human operators to continuously watch its operation and to intervene as and when felt
necessary by them. This requires an interface between the SCADA system and the
human operators. The same is provided as a standard practice in the MTU located in
the control room. The MTU is built and functions around a computer. Therefore, the
human-SCADA interface is realised through human-computer interface, commonly
known as human-machine interface (HMI) and sometimes as graphic operator
interface (GOI).
Role of HMI
The human-machine interface (HMI) enables the operator:
(a) to ‘watch’ the process/plant being monitored and controlled by SCADA system, and
(b) to ‘intervene’ as and when considered necessary by him.
2.3 What Does HMI Comprise?
In order to perform the above role, the HMI comprises suitable hardware
(input/output devices or computer peripherals as discussed below) and the related
software drivers (or data transfer software):
Input Devices for HMI: The input device almost always used for HMI is the standard
(ASCII) keyboard, one on each operator console. For any intervention in the computer
control, the operator can use the keyboard for entering: (a) data, and (b) instructions.
Output Devices for HMI: The following output devices are used for HMI:
(i) The mostly used output device is the video monitor or visual display unit
(VDU), which works along with a computer mouse. One monitor-mouse pair is
provided on each operator console. Colour LCD monitors of high resolution are
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now used to achieve a good visual impact in presenting alpha-numeric values,
status, events, alarms, tables and graphs to the operator.
(ii) Very often, a speaker is provided on the operator console for issuing audio
alerts and audio alarms to the operator.
(iii) A large wall-mounted high-definition LED screen is used for displaying boldly a singleline diagram (SLD) of the process flow, called as mimic diagram or simply mimic, and the screen is traditionally known as mimic board. The purpose of the mimic is to present at-a-glance picture or overview of the complete process to the operators. It can be either static or dynamic. A static mimic displays only a SLD of the process, whereas a dynamic mimic displays the real-time status of major objects in the plant and the current measured values of important variables, both laid over the SLD of the process.
(iv) One or more printers are included for generating hard copy of (a) programs, (b)
screen shots, and (c) reports.
2.2.2 Electrical Communication
Electrical communication is required:
(a) Between the MTU and each RTU, and
(b) Between each RTU and the field devices connected to it.
Details of these communications are given below.
2.2.3 MTU-RTU Communication
Each RTU is expected to acquire data: (a) analog values of important variables, and
(b) status information of important objects, from the plant section assigned to this
particular RTU and to transmit data to the MTU after necessary processing of the
acquired data. Likewise, each RTU expects to receive control instructions: (a) set-
points, and (b) discrete control commands, relevant to the plant section assigned to it,
from the MTU and deliver them to the plant. This necessitates two-way (or duplex)
digital communication between RTUs and the MTU.
There is no need of providing individual point-to-point communication links between
each RTU and the MTU. Such an arrangement would require the MTU to have one
transceiver (transmitter + receiver) per RTU and the total length of communication
cables would also be very large. This would make the cost of MTU-RTU communication
subsystem very high and its performance and reliability very poor. A much better option,
which is now commonly used, is to provide/ use a single data network linking all the
RTUs with the MTU. However, depending on the geographic size of the controlled
process and dispersion of its facilities, the following options are used for the data
network:
(a) LAN (local area network): It is quite common to use multiple LANs working on
different protocols.
(b) MAN (metropolitan area network)
(c) WAN (wide area network)
(d) Internet: For a public utility spread over a nation or beyond, even the Internet
may be used subject to data security considerations.
2.2.4 RTU-Field Device Communication
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Each RTU acquires the analog values of controlled and uncontrolled variables of the
process through analog sensors and the status information from remotely and locally
controlled objects in the plant using status sensors. Similarly, it delivers the set points to
automatic or feedback controllers (of the controlled variables) and discrete control
commands to various actuators (of the remotely controlled objects). Thus these devices
(analog and status sensors, feedback controllers and actuators), known as field devices,
act as the interface between the RTU and the controlled process/ plant. The following
important points should be noted in regard to the communication between an RTU and
the related field devices:
(a) The communication between simple (non-smart) field devices and RTU is in one
direction only or simplex, as against an essential duplex communication between RTUs
and MTU. To clarify the point further, the information or signal has to travel only from
non-smart sensors to the RTU, but not from RTU to the sensors. Similarly, the
information to the unintelligent controllers and actuators has to come from RTU and no
information or signal goes from these devices to the RTU.
(b) The status information going from the status sensors to the RTU is essentially discrete
(or binary) in nature. This information is sent using binary signals (high/low or 1/0
signals).
(c) The control commands delivered by the RTU to the actuators are also discrete (or
binary) in nature. These are also sent using binary signals.
(d) The information going from the analog sensors to the RTU is analog in nature. This
analog information is either transmitted as such to the RTU using analog communication
(4-20 mA is the most widely used analog signal) or is first converted to digital value
using an analogto-digital converter (ADC) and then transmitted using digital
communication techniques.
(e) The set points received by the RTU from the MTU are always digital in nature, because
RTU-MTU communication is always digital. The RTU can deliver it in digital form itself
using digital communication, provided the automatic controller receiving it is also of
digital type. But if the controller is of analog type, the RTU will convert it to analog value
(4-20 mA most likely) using a digital-to-analog converter (DAC) and send this analog
signal to the controller.
(f) If smart or intelligent field devices, like smart meters, are used, then a two-way digital
communication will be required between them and the RTU. In fact, a local area network
(LAN) can be set up for the communication between such field devices and the RTU,
with the attendant benefits of lower cost, reduced wiring/cabling and higher reliability.
(g) Intelligent electronic devices (IEDs), like digital protective relays and digital controllers
equipped with data communication facility, can communicate with MTU either through
an RTU or directly.
2.2.5 Data Acquisition (DAQ) and Transmission
Data are acquired and processed by RTUs and transmitted to MTU on the MTU-RTU data
network.
As briefly mentioned under the review of SCADA system, two types of data are
continuously acquired by the RTU:
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(a) Analog Values: Values of the uncontrolled as well as controlled variables, which are
almost always analog in nature, are acquired continuously using suitable analog
sensors (or transducers), signal conditioners and a microprocessor-based data
acquisition circuit. The sensors are naturally placed at the locations where the variables
are located. The signal conditioners may be located close to the sensors or inside the
RTU or in front of the RTU. In the last case, the external signal conditioner processes
the electrical signal coming from a sensor before inputting it to the RTU. In case of a
smart sensor, the signal conditioning circuit is integrated with a micro-sensor in a single
chip. Data acquisition circuit is an internal and important component of the RTU.
(b) Status Information: Information about the states of remotely as well as locally
controlled objects, which is essentially discrete or binary in nature, is also acquired
continuously. This is done using suitable status sensors and a data acquisition circuit.
When are Data Transmitted?
The data acquired as above is processed in the RTU to extract the information as
required by the MTU. Details of the data processing will be taken up under the
“calculation” function of RTU. The extracted information (or processed data) is
transmitted by the RTU to the MTU on five occasions:
1 Periodically at a pre-determined rate (this rate is often different for different data).
2 Whenever an event takes place (event means a change larger than a predefined
change from the normal or the previous value of a variable or a change in the state of
an object).
3 On start-up of the plant or process.
4 Whenever the process or plant is restarted. (v) In response to a demand made by MTU.
The operator workstations are used for monitoring all system operations and for effecting control actions and parameter adjustments. These operator workstations are generally referred to as ‘clients’ since they obtain their current and historical data from the ‘server’ computer. There are normally multiple operator workstations, as illustrated in Figure 10.2, each of which contains all of the process graphic displays and historical trend displays for the system. Users of the SCADA system can log into the system through these workstations.
Some of the operations performed through the Operator workstations are listed below; more details about the displays required for these actions will be provided later in this chapter:
Logging on and off the system using passwords and user names
Invoking process displays to view the operations throughout the system
Effecting control modes for various equipment in the system; for example, Manual and Automatic modes, placing equipment in or out of service
Changing set point parameters, with appropriate security allowance
Effecting manual control actions for equipment, such as start/stop and open/close
Viewing historical trend displays and transferring data to other files for exporting
Viewing the current alarm summary to identify alarm conditions requiring attention
Viewing the alarm/event summary to view the chronological series of events.
The operator workstations provide the user interface or HMI to the SCADA system. Users can effect control over the equipment, as well as invoke displays which show current and historical information about any aspect of the SCADA system
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2.2.6 Monitoring
It is a common practice to monitor (a) status, (b) events, (c) limits and (d) trends.
This function (monitoring) is carried out jointly by RTU and MTU as discussed below.
(a) Status Monitoring
As one its important functions, the RTU determines the status of two-state objects
from the status information acquired continuously by it (as already discussed under
Data Acquisition). It takes some finite time for the object to change from one stable state
to the other stable state. Thus the object is in an intermediate but unstable state during
the change-over. The method of determining the status should be such that the decision
of the RTU is not vitiated by this intermediate state. Very often, this is achieved by
introducing a delay in making the decision, which is a little more than the operating time
of the object. The status of important objects monitored by the RTU in this way is
transmitted by it to the MTU for displaying to the operator on video monitor.
(b) Event Monitoring
Generally it is the RTU which is responsible for detecting events and intimating to
the MTU. The RTU compares the current value of a variable against its previous, normal
or reference value. If the change exceeds a predefined increment or decrement, an
event is said to have taken place. Similarly, the RTU compares the current status of an
object against the previous, normal or reference state of that object. If the change is of a
predefined type, an event is said to have occurred. Moreover, the event can be one of
the following types:
(i) Instantaneous Event: It means an abrupt change or a change without
any intentional delay. This type of event is communicated at once by the RTU to
the MTU.
(ii) Delayed Event: It means a change with an intentional delay. It is
communicated by the RTU only when the change is completed.
(iii) Sequential Event: It means a sequence of activities or changes. This type of
event is communicated by the RTU on the completion of the sequence.
In each case, as and when an intimation of the occurrence / completion of an event
is received by the MTU, it stores the same in its computer memory and annunciates or
displays suitably to the operator on speaker/ buzzer/ video monitor of HMI.
(c) Limit Monitoring
Four sets of limits are monitored in a well-designed SCADA system:
(i) Reasonability Limits: Every feedback controller is expected to monitor
and maintain the value of the variable controlled by it within a pair of upper and
lower limits, called reasonability limits. In case the value of the variable tends to
rise above the upper limit or fall below the lower limit, the controller take
corrective action to keep the value within the limits.
(ii) Warning Limits: The computer in the MTU monitors critical variables in
the process against certain predefined limits on the basis of the data coming
from the RTUs. In case such a limit is found violated, the computer displays a
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warning message to the operator on video monitor. Alternatively, the RTU
monitors these variables and, in case of a violation of limits, communicates this
fact to the MTU for warning the operator. The operator is then expected to
intervene and take a planned action before the situation becomes alarming.
(iii) Alarm Limits: If the operator fails to act on a warning, some critical
variables may cross the farther set of alarm limits. When alarm limits are
violated, the computer of the MTU generates an audio alarm so that the
operator takes an emergency action before the system becomes unstable or
unsafe. An alarm is in the form of sounding a buzzer or pronouncement on a
speaker.
(iv) Safety Limits: In case a certain parameter crosses a predefined limit
indicative of danger to the process, plant or personnel, the concerned protective
device in the plant generates a command to shut down a part or whole of the
process. For example, in the event of an electrical fault, one or more circuit
breakers are tripped by protective relays to shut off power supply to a part or
whole of the process/plant.
(d) Trend Monitoring
The following trends are generally monitored:
(i) Variation of critical/ important parameters with time , and/
or (ii) Rate of variation of critical/ important parameters.
These trends usually reveal the working and health of the system much more than do
the absolute values of the system parameters. The trends are calculated in real time by
the computer of the MTU from the data received by it from the RTUs, and are displayed
to the operator as curves on video monitor to enable him to take appropriate action as
and when he notices an abnormal trend.
2.2.7 Control Control instructions (set points and discrete control commands) are sent by MTU to
the RTUs. The set points received by an RTU are delivered by it to the concerned
automatic controllers. The discrete control commands received by an RTU are executed
as under:
(a) A simple device control command is delivered by the RTU to the concerned
actuator.
(b) When a sequential control command is received by an RTU, it initiates the
intended sequence of actions.
(c) When a regulation command (like ‘raise-lower’, or ‘up-down’ command) is
received by an RTU it is interpreted by the RTU and delivered to the related
actuator. For example, ‘raise’ command is delivered to the ‘lower’ terminal of a
gate controller for raising a dam gate continuously as long as the ‘raise’
command continues and ‘lower’ command is delivered to the ‘lower’ terminal of
the gate controller for similarly lowering the gate continuously as long as the
‘lower’ command is present.
2.2.8 Data Collection, Storage and Retrieval
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As explained earlier, each RTU acquires certain data from the controlled process/
plant, processes it appropriately, and then transmits to the MTU at appropriate instants.
Some of the data so received by the MTU is stored in the mass-storage media of the
MTU. An operator can later on retrieve a block of data of his interest from the storage
and recreate an event, sequence or history for visualization and analysis
Three types of data are stored by the MTU in its mass-storage media:
(a) Disturbance Data: Short duration data, the duration of which ranges
typically between a few seconds to several minutes, is stored for recording a
disturbance in the process.
(b) Historical Data: Medium duration data, its duration ranging from a few
hours to several days, is recorded for keeping a history of operation of the
process.
(c) Planning Data: Long duration data, recorded typically over a month, a
quarter of a year, one full year, or even a few years, is meant to serve as a vital
input for planning.
Time Stamping of Data
The data received from various RTUs is stored with chronology to recreate a
disturbance event or a historical event. To that end, the individual data must be tagged
with the time of its occurrence, or ‘time-stamped’, either at the receiving end (that is by
the MTU) or at the transmitting end (that is by the individual RTUs). Because of variable
delays in transmission of data from different RTUs to the MTU, the first option can
distort the sequence of activities represented by the data. On the other hand, the
second option can distort the data if the time clocks of various RTUs are not
synchronized. The best option is synchronize the clocks of all RTUs and MTU and to
time stamp the data at RTUs. If the controlled process is located within small premises,
synchronizing the clocks of all RTUs and MTU becomes a simple task. On the hand, if
the process is spread over a large area (typical in the case of utilities), the time clocks of
all RTUs and MTU are synchronized using GPS (geographical positioning system) or
any other technique.
2.2.9 Calculation :Calculations are made both in RTUs and MTU. The nature and extent of these calculations are brought out below:
Calculations in RTU
The microprocessor of an RTU is required to perform simple calculations or data
processing, such as:
(a) Filtering the data acquired by it to remove noise,
(b) Extraction of desired information, like maximum, minimum, rms or average value
or rate of change, from filtered data,
(c) Conversion of numbers to values in engineering units, and
(d) Compression of data to reduce data-transmission-rate and storage
requirements.
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Calculations in MTU
The calculations that need to be made by the computer of the MTU are in general
fairly extensive and complex. These calculations are made for predicting the behavior of
the system (controlled process) through mathematical modeling for certain anticipated
conditions and certain inputs to the system, both for normal and contingency
operations. The output of these calculations is a set control instructions to be sent to
different RTUs for each set of system conditions and inputs. The calculations are
usually made on floating-point numbers and in batch mode.
2.2.10 Report Generation
One of the important functions of SCADA software is to generate a vast number of
reports on the basis of the data stored by the MTU. To that end, SCADA software
includes a report generator module, which retrieves data from the MTU database and
generates the desired reports from it. The software module allows the user to choose
the format of reports, customize the style of reports, insert graphics and even perform
calculations
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet
provided in the next page:
1. What are the five components of SCADA system?
2. Data are acquired and processed by _______ and transmitted to ________
on the MTU-RTU data network.
3. What is the role of HMI(human machine interface ?
4. List the function of SCADA system
5. What are types of monitoring in SCADA system?
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
Rating: ____________
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3.1 Introduction
The SCADA system begins with a supervisory concept in the field of the ICS
(Industrial Control System). Management of industry data is important to an
administration control system. Data acquisition from equipment like PLC
(programmable logic controller) in real time and organized reports improves
company management solutions. Solutions like this, allied to industrial automation,
result in quality improvements.
PLC is a Programmable Logic Controller. It is a hardware that can be used to control process in factory plan.
Its information can be passed to the PLC SCADA systems in a computer.
The SCADA can monitor in real time, control, record and generate reports from this information.
In a supervisory, the SCADA systems organize that information from the industrial factory through communication with PLC and data acquisition equipment. The information goes from users in a factory to general management.
The SCADA systems can monitor the industrial information through HMI panels in screens and reports with data from the recorded database.
The data acquisition can be stored in databases and distributed as needed.
SCADA panels can be replicated in the network via LAN / WEB. Several users are able to monitor the SCADA system supervisory.
The screen can be customized according to each case.
HMI objects are distributed in monitor creating control panels and plant schemes. Animated objects pictures with graphic information are used to improve SCADA supervisory.
These objects can be displays, controls, bar graphs, gauges, valves, pumps, buttons, charts, etc.
3.2 SCADA control system with supervisory:
They can interact with SCADA users clicking and typing.
When these objects are used, information can be sent to PLC to control data acquisition in the factory.
SCADA data is passed to them. Users are able to get SCADA information through this.
The PLC SCADA can control the supervisory information through users and programming applications.
Scripts can be used for programming an application.
Automate systems getting input information, calculating and generating output data to the factory.
Information Sheet-3 Identifying range of information able to be provided to team
by SCADA system
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3.3 SCADA programming:
The SCADA systems are programmable according to each supervisory case.
If some data are included in some condition then information are sent to the PLC equipment.
And logical conditions define SCADA systems way to proceed the specific applications.
This programming can be made via script in SCADA.
The SCADA systems control automation in the factory.
Scripts are commands in several languages depending on the platform.
These commands can send and receive data to the SCADA system according to the each application case.
3.4 PLC SCADA:
Data acquisition that came from PLC is made through networks like Ethernet and serial.
Each PLC has protocols defined over these supervisory networks.
For example, Ethernet can be used with MODBUS TCP protocol.
There are several PLC with communication that can be used in SCADA automation.
These PLC can be distributed in a factory and connected.
The SCADA systems can centralize supervisory information of all PLC in net.
3.5 SCADA database:
SCADA system data are recorded in a database. This database can be SCADA proprietary or ODBC base.
Databases are tables of values that are used to store information about the system.
Each table has fields. Each field can be SCADA tag from PLC or variable.
Database fields may store values in number or text format according to the case.
Each register is a set of fields recorded.
Each scanning value is a register.
Inside this register, it can be stored a time field and header information before the values from data acquisition.
Auxiliary tables of products, recipes, customers, etc... can be used in SCADA system to improve. PLC data acquisition passed to supervisory SCADA can be stored in this database.
3.6 SCADA reporting system: After data stored in the database, reports can be generated.
Listing of the SCADA system tag fields. They can be formatted according to each case.
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Several reports of PLC SCADA data acquisition are created to the manager.
Alarms can be set to trigger events. Limits maximum and minimum for each tag case.
Calculation according to process.
These SCADA system alarms are stored and recognized. Can be set in real time.
When data acquisition values reach alarm limits an event can be triggered.
The alarm is stored and informed to the SCADA system. Security: Another important issue is security. For example, remote applications must be secured from non-authorized external controls. Temperature SCADA system: SCADA information of temperature can be monitored. Low, average or high temperatures are stored to assure process quality. Limits and alarms are set to quality assurance. If some temperature reaches limits, an occurrence is triggered for action and explanation in report system. When SCADA recipes are set, SCADA system must control from start to finish of each process in the factory. In temperature control, a set point must be defined for each case. Microcontrollers can be used to set data PID in the industry. Pressure SCADA system. SCADA information of pressure can be monitored. Limits and alarms are set to quality assurance. If some pressure reaches limits, an occurrence is triggered for action and explanation in report system. When SCADA recipes are set, SCADA system must control from start to finish of each process in factory company. SCADA production counting. SCADA system can do the counting of products on a production line. Each product that passes to sensor sends to PLC a signal. A counter is used as a tag in SCADA to increase value to the number of items. These items can be products, objects, events, users, etc... SCADA water treatment In the SCADA system, each step of water treatment can be supervised and controlled. Levels, pressures, temperatures, events, alarms, etc... Pumps can be monitored and triggered when needed. Valves also are controlled by SCADA. Each variable can be reported in SCADA that was recorded in the database.
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet
provided in the next page:
1. Discuss the steps that help to develop a Schedule in a Project
2. What is the purpose of scheduling?
3. What is the purpose of project planning?
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. …………………………………………………………………………………………
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Score = ___________
Rating: ____________
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Instruction Sheet 2 Learning Guide 65: Communicate using SCADA system
This learning guide is developed to provide you the necessary information regarding the following
content coverage and topics
Sending and receiving Information and messages using SCADA.
Choosing Telephone Modem, (PLL), (DDS) and ISP
Choosing Radio Transmission System
Choosing Satellite Transmission System.
Choosing Dedicated Wire/Power Line Modems. This guide will also assist you to attain the learning outcome stated in the cover page. Specifically, upon
completion of this Learning Guide, you will be able to
Send and receive Information and messages using SCADA.
Choose Telephone Modem, (PLL), (DDS) and ISP
Choose Radio Transmission System
Choose Satellite Transmission System.
Choose Dedicated Wire/Power Line Modems.
Learning Instructions:
1. Read the specific objectives of this Learning Guide.
2. Follow the instructions described in number 3 to 14.
3. Read the information written in the “Information Sheets 1”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
4. Accomplish the “Self-check 1”
5. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 1).
6. If you earned a satisfactory evaluation proceed to “Information Sheet 2”. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to Learning Activity #1
7. Submit your accomplished Self-check. This will form part of your training portfolio.
8. Read the information written in the “Information Sheet 2”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
9. Accomplish the “Self-check 2”
10. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 2).
11. Read the information written in the “Information Sheets 3 and 4”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
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12. Accomplish the “Self-check 3” in page __.
13. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 3).
14. If you earned a satisfactory evaluation, proceed to “Operation Sheet 1” in page _. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to for each Learning Act
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1.1 Introduction.
Many different communications media can be considered for SCADA new projects or to
upgrade obsolete SCADA communications systems. The selection of any of these
communications media depends on the technical requirements for the application,
geographic considerations of remote facilities to be monitored / controlled, the availability of
established systems, and economics These different communications technology applicable
for SCADA systems are described in subsequent sections with tables showing each
technology advantages and disadvantages.
Any media capable of supporting serial binary signaling, including the following may provide
the necessary communications facility between SCADA system master and remote
terminals:
• Copper Cable
• Coaxial Cable
• Fiber Optic Cable
• Power Line Carrier (PLC)
• VHF/UHF Radio (Conventional or Trunking)
• Microwave Radio
• Satellite (VSAT, LEO, Others)
Data acquisition refers to the method where information can be automatically or manually
exchanged between remote facilities and centralized control centers. RTU’s in a remote
plant will be exchanging data with connected field devices or sensors, such as flow meter,
ammeter, valves, actuators, motors, etc. The central host will be then exchanging data with
dispersed RTU’s located at remote facilities via communications networks. The operator will
have a graphical interface that represents a plant or equipment displayed with their
associated readings. As the data changes in the field the operator graphical interface will be
updated accordingly.
1.2 COMMUNICATIONS MEDIA
Transmission medium is the physical path between transmitter and receiver in a
communication network. The transmission media used for SCADA systems include copper
cable, coaxial cable, fiber cable, electromagnetic propagation through the atmosphere, or
hybrid media using combinations of different media
The various media can be described using the set of characteristics described below
Physical description: the nature of the transmission medium
Information Sheet-1 Sending and receiving Information and messages using
SCADA
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Transmission Characteristics: include whether analogue or digital transmission, modulation scheme, capacity, bandwidth, and frequency range over which transmission occurs
Connectivity: point-to-point or multipoint
Geographical scope: the maximum distance between points on the network
Noise immunity: resistance of the medium to interference
Relative cost: cost of hardware and software, installation, maintenance and lease
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in
the next page:
4. List the communication media used in SCADA system
5. Explain Communication media
6. Describe the characteristics of Communication media
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. …………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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2.1 Choosing a Transmission Mode
The transmission mode defines the way information is sent and received between and/or
among devices on a network. For SCADA systems, your network topology generally
determines your data transmission mode
Table 2.1 SCADA systems network topology
If you have chosen this Then your transmission mode is Which means
topology
Point-to-multipoint Half-duplex Information is sent in one direction at a time over the link.
transmit receive
Station
A
Station
B
receive transmit
Point-to-point Full-duplex
Information is simultaneously sent and received over the link.
transmit receive
Station
A
Station
receive transmit
B
Multipoint-to-multipoint Full-duplex (between station and Information is simultaneously sent and received over the
modem) station to modem link, whereas information is sent in only
Half-duplex (between modems) one direction at a time over the modem to modem link.
transmit
receive
transmit
receive
receive
Station Modem Modem
B
Station
B
A A
receive transmit receive transmit
receive transmit
Information Sheet-2 Choosing Telephone Modem, (PLL), (DDS) and ISP
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2.2 Choosing a Link Media
When choosing link media, consider the following:
Data transmission needs of the application
Remote site and control center locations
Distance between sites
Available link media services
Project budget Several types of link media are available, including public transmission media, atmospheric
media, and dedicated line media.
Table 2.2 types of transmission media
Media Category Type
Public transmission
Media
Public-switched telephone network (PSTN);
Internationally: general switched telephone network (GSTN)
Private leased line (PLL)
Digital data service (DDS)
Internet via ISP
Atmospheric media
Microwave radio
VHF/UHF radio
Geosynchronous satellite
Cellular network
Dedicated line Dedicated wire
Power line
2.3 Public-switched Telephone Network (PSTN) or General Switched Telephone Network (GSTN)
The dial-up network is furnished by a telephone company. This telephone line is the
one that we use daily and that carries voice and data transmissions.
Advantages/Capabilities
Public-switched telephone networks are cost-effective for: short, occasional data collection from remote sites that have access to a
PSTN. sites calling in to a central location.
Often point-to-point applications have a dial-up connection as a backup to the main
media link.
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The phone company charges a monthly fee based on usage – the number of local connections made and/or the time and distance of each long distance connection.
The network supports communication rates of up to 57,600 bps.
The network is a 2-wire connection that supports half-duplex modems and 2-wire, full-duplex modems. The topology is point-to-point.
Disadvantages
Transmission is costly for long, frequent data collection from remote sites.
The lines can contain impairments that can cause modems to have error rates of
less than 1 error per 1,000,000 bits.
The media cannot be used in areas that do not have access to the network, such
as an offshore oil or gas well.
Time is required to dial and establish each connection.
Additional logic is required to automatically initiate a connection. Equipment Required
Use standard Bell or Consultive Committee for International Telephone and Telegraph
(CCITT) modems. Contact the telephone company for information about connecting to
the network.
2.4 Private Leased Line (PLL) PLL is a dedicated telephone line that is a permanent connection between two or more locations and that is used for analog data transmission. The line is available 24 hours a day. In order for the line to be used for voice communication, a voice option must be installed.
Advantages/Capabilities
The media is cost-effective for applications that
require large amounts of data to be collected frequently from remote sites and/or
applications that require remote sites to have a constant connection to the
master station.
Regardless of how much you use the line, the
phone company charges you a flat, monthly fee based on the following:
Distance between sites Area of the country Type of line conditioning
Leased lines have different levels of conditioning, or grades - the higher the
grade, the greater the modem data rate that can be supported by the link,
and the more the phone company charges for it.
The standard, unconditioned line, supports speeds of up to 56 Kbps.
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Private leased lines provide a 4-wire connection.
You can purchase modems that operate the circuit in either half- or full-duplex
mode. You can also order a 4-wire multi-drop line.
Disadvantages
The media cannot be used in areas that do not
have access to the network, such as an offshore oil or gas well.
The lines can contain impairments that can
cause modems to have error rates of less than 1 error per 1,000,000 bits.
Equipment Required
Use standard Bell or CCITT modems. Contact the telephone company for
information about connecting to the network.
2.5 Digital Data Services (DDS)
DDS is a special wide-bandwidth private leased line that uses digital techniques to transfer data at higher speeds and at a lower error rate than private leased lines. The line is available 24 hours a day
Advantages/Capabilities
DDS is a digital network that offers higher transmission rates and minimal, if any, line impairments.
The media is useful when an application requires very large amounts of data to be transferred between sites with a low data error rate.
Regardless of use, the phone company charges you a flat, monthly fee based on the following: Distance between sites Area of the country Speed of the integrated service unit (digital ‘modem’)
A constant connection exists.
Asynchronous communication rates are 2.4 K, 4.8 K, 9.6 K, 19.2 K, 38.4 K, and 57.6 Kbps.
The network provides a four-wire connection and can be configured in a multi-drop topology.
Disadvantage
The media is costly for applications not needing to transmit large amounts of data quickly and at a low data error rate.
Equipment Required
Use standard integrated service unit, ISU (also called a data service unit [DSU] or channel service unit [CSU]). The ISU data rate must match that of the digital data service line, which operates at a fixed rate.
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2.6 Internet via Internet Service Provider (ISP)
Advantages/Capabilities
High-speed broadband Ethernet network
connections readily available in metropolitan areas
Low monthly fixed cost for continuous data connections
Minimal capital costs
Remote access possible to/from anywhere on the Internet
Disadvantages
Dependent on a public network (may not be available when needed most)
Requires network security precautions to prevent unauthorized access
Equipment Required
Ethernet router/modem (typically provided by ISP)
Ethernet security hardware (for example, firewall or VPN)
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet
provided in the next page:
1. List the type of Public transmission Media
2. List the type of Atmospheric media
3. Explain Dedicated line media
4. Explain Private Leased Line (PLL)
5. Ex[plain Digital Data Services (DDS)
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. ………………………………………………………………………………………………
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2. ………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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3.1 Microwave Radio
Microwave radio is a high-frequency (GHz), terrestrial radio transmission and reception
media that uses parabolic dishes as antennas. The dishes are usually mounted on towers
or on top of tall buildings, since this is a line-of-sight topology.
Microwave radio systems are systems that operate in the microwave frequency spectrum. A
microwave is a signal that has a wavelength of one foot (30.5 cm) or less. A wavelength of
one foot converts to a frequency of 984 MHz, so all frequencies above 1 GHz are
considered to be microwaves. While the microwave frequency range theoretically extends
into the light frequencies, the practical uses of microwave are between 1 and 300 GHz.
Advantages/Capabilities
The media links geographically-remote areas that
are not accessible by phone lines.
A constant connection exists.
Transmissions can occur over very long distances over rough terrain.
You incur no monthly service fee because you own
the equipment. The only expenses are operation and maintenance costs.
Low transmission delay times exist.
The larger bandwidth allows you to multiplex many
channels over one antenna.
Lease circuits from another company who owns
their own private microwave circuit.
Disadvantages
Transmission is limited to a line-of-sight, for example, you cannot transmit through
mountains. The signal can experience distortion and interference. Also, atmospheric
conditions such as rain, snow, or fog can affect the signal.
Most microwave link frequencies are allocated and regulated by the Federal
Communications Commission (FCC). In urban areas, fewer data-transmission
frequencies are available.
You can incur large initial expense for equipment.
Equipment Required
Transmitters
Receivers
Parabolic dish antennas
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Repeaters are needed to transmit long distances over hills or mountains
3.2 VHF/UHF Radio SCADA through radio is a mean of communications without the existence of a physical
connection between the transmitter and the receiver. It can, for example, be used as a
replacement for a physical link where difficult terrain or natural obstacles militate against
such link, or where the transmitting or receiving end is in motion and the attachment of a
physical link is impossible. The main limiting factor in the use of radio SCADA is distance –
and the distance to be covered defines the type of radio system applied and the frequency
used.
VHF/UHF radio is a high-frequency electromagnetic, wave transmission. Radio transmitters
generate the signal and a special antenna receives it.
Advantages/Capabilities
The media links geographically-remote areas that are not accessible by phone
lines.
A constant connection exists.
Transmissions can occur over rough terrain and over distances of less than 30 miles.
You incur no monthly service fee because you own the equipment. The only
expenses are operation and maintenance costs.
Minimal transmission delay times exist.
Disadvantages
Repeaters are needed to extend transmissions over
distances greater than 15 miles.
Most radio link frequencies are allocated and
regulated by the FCC. In urban areas, fewer data-transmission frequencies are
available.
The signal from 900 MHz and higher
transmitters can experience distortion and interference, and can be affected by
poor weather conditions.
The narrow bandwidth carries only one channel.
You incur an initial expense for equipment; less
expensive than microwave or satellite.
Equipment Required
Transmitters
Receivers
Antennas
Repeaters are needed to transmit greater
distances and over hills and mountains
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in
the next page:
1. Explain Microwave Radio transmission system
2. Explain VHF/UHF Radio transmission system
3. List the equipment required for VHF/UHF Radio transmission system
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
Rating: ____________
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4.1 Introduction
Geosynchronous satellites use a high frequency (GHz) radio transmission to route transmissions between sites. The satellite's orbit is synchronous with the earth's orbit (geosynchronous); therefore, the satellite remains in the same position with respect to the earth. Satellites receive signals from and send signals to parabolic dish antennas.
4.2 Satellite (VSAT, LEO)
Satellite-based SCADA is especially useful when the geographic placement of elements in the controlled network is diverse through large areas with “virtually no terrestrial communications networks”, removing the requirements to lay hundreds or thousands kilometers of wire. It is also a good choice when other information such as voice, fax or local area network traffic is combined with SCADA stream. The point-to-multipoint nature of the satellite networks is advantageous for multicasting of polling queries, commands and network timing Table shows different satellites constellations.
TABLE FEATURES OF DIFFERENT SATELLITES CONSTELLATIONS TYPE LEO MEO GEO
Satellite Low Earth
Orbit Medium Earth
Orbit Geostationary
Earth Orbit
Altitude (km) 800 - 2000 9,600 –
19,200 36,000
Bands VHF, UHF,
LBand L-Band, S-
Band C-Band, K- Band, Ka- Band
Applications Positioning, Fixed
Terminals, Mobile Terminals,
Data,
Positioning, Fixed Terminals, Mobile Terminals, Data, Voice
Positioning, Fixed Terminals, Mobile Terminals, Data, Voice
4.3 VSAT
VSAT systems (Very Small Aperture Terminal) are designed to provide fixed telephony and data services. VSAT systems are using geo-stationary satellites and offer continuous coverage over a particular area of the earth. While older VSAT systems used the C-band (6/4 GHz), current systems generally use the Ku-band (14/12 GHz) and newer systems use the Ka-band (30/20 GHz). For example, as Figure II shows, VSAT network can be configured as a point to multi-point system capable of allowing numerous remote sites to communicate with a centralized computing facility or HOST. The remote terminals are typically installed at dispersed sites and are connected to the HUB via a satellite link. VSAT remote terminals with low power consumptions are preferred for unmanned remote sites with modest communications requirements.
The cost of VSAT equipment and services has decreased significantly. In addition, Remote VSAT terminal equipment in ruggedized containers can withstand extreme weather conditions, eliminating the need for expensive shelters
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FIG 4.1: SCADA SYSTEM VIA VSAT
4.4 LEO
When initially introduced, Low Earth Orbit (LEO) systems were promising to allow for end users’ equipment with less complexity and low power consumption with a global coverage. LEO system is designed to provide global data and voice services via group of LEO satellites and ground infrastructure. There have been discussions on how LEO systems can provide SCADA communications. The two major challenges for LEO systems to be used for SCADA systems are time latency and re-routing traffic to third party ground stations. Further investigations need to be carried out before considering LEO systems for SCADA communications.
Table shows the Satellite Systems advantages and disadvantages
TABLE 4.1 SATELLITE RADIO ADVANTAGES / DISADVANTAGES
Advantages Disadvantages
Easy to install, short implementation
cycle
Broadcasting Capabilities
Cost effective compared to terrestrial
networks
Wider Area Coverage
Channels coast are almost distance
independent
Time Latency
May be dependent on other operators
Satellite Life Span
Downtime are expected, e.g. satellites’
eclipses
4.5 Cellular Network Advantages/Capabilities
High-speed broadband Ethernet connections
readily available in metropolitan areas, as well as in many rural areas where
no other communication options exist other than satellite
Lower fixed and monthly costs vs. satellite
Minimal capital costs
Remote access possible to/from anywhere on the Internet
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Disadvantages
Dependent on a public network (may not be available when needed most)
Requires network security precautions to prevent unauthorized access
Equipment Required
Cellular Ethernet router/modem Ethernet security hardware (for example, firewall or VPN)
DESIGN EXAMPLES
Engineers designing SCADA systems need to consider all communications alternatives to
come up with the most efficient and cost effective solutions. Alternatives are only rejected
after proofing they are not efficient or not cost effective.
As in the example shown in Figure III, cluster of remote well sites RTU’s are connected
through VHF/UHF radios and then they are all connected back to a centralized operation
control center through a satellite link. This example is only showing that various
communications technologies can be implemented for SCADA projects if applicable.
FIGURE 4.2: SCADA COMMUNICATIONS EXAMPLE
Gas Field
VHF/ UHF
Radio
Remote Wellsite RTU VHF/
UHF Radio
Remote Wellsite RTU
VHF/ UHF
Radio
Local Control
Satellite
Main Operation
Control Center
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in
the next page:
1. Explain VSAT system
2. Discuss the advantage and did advantage of LEO system
3. Discuss the advantage and did advantage of cellular network system
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
Rating: ____________
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5.1 Dedicated Wire You can transmit and received data over a pair of copper conductors for extended distances with
dedicated wire modems
I. Copper Cable
Twisted-pair copper cable is the most popular medium used for SCADA communications
and it has been used in its present form for many years. It is similar to copper cables
used by telephone companies and contains pairs of conductor. Copper cables used for
SCADA purposes can be underground, direct buried or aerial installations. Aerial cables
would be more appropriate in the utilities’ service area since they may own a large
number of distribution poles from which cable could be suspended. Table I shows the
Copper Cable advantages and disadvantages
TABLE I: COPPER CABLE ADVANTAGES / DISADVANTAGES
Advantages Disadvantages
No licensing, fewer
approvals For utilities’
services, existing pole
infrastructure could be used
Economical for short distances
Relatively high channel capacity for
short distances
Right-of-way clearance is required for buried cable
Subject to breakage
Subject to water ingress
Subject to ground potential rise due to power faults
and lightning
Failures may be difficult to pinpoint
Inflexible network configuration
II. Coaxial Cable
Coaxial cable is simply a transmission line consisting of an unbalanced pair made up of an
inner conductor surrounded by a grounded outer conductor, which is held in a concentric
configuration by a dielectric. The dielectric can be of many types, such as polyvinyl chloride,
foam, Spirafil, air or gas [Roger L. Freeman, 1989]. Coaxial cable can transmit high
frequency signals up to several MHz with low attenuation compared to copper wires used
for telephone services. Methods of coaxial cable installations are underground, direct buried
and aerial constructions. Table II shows the Coaxial Cable advantages and disadvantages
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TABLE II: COAXIAL CABLE ADVANTAGES / DISADVANTAGES
Advantages Disadvantages
No licensing, fewer approvals
For utilities’ services, existing pole
infrastructure could be used
Economical for short distances
Relatively high channel capacity than
copper cables
More immune to RF noise interference
than copper cables
Right-of-way clearance is required for buried
cable
Subject to breakage
Subject to water ingress Subject to ground
potential rise due to power faults and lightning
Failures may be difficult to pinpoint
Inflexible network configuration
III. Fiber Optic Cable
Fiber optic as a transmission medium has a comparatively unlimited bandwidth. It has excellent properties as low as 0.25 dB/km. Losses of this order of magnitude, as well as the development of suitable lasers and optical detectors, allow designers to consider fiber optics technologies for systems of huge bandwidth over long distances.
Optical fibers consist of an inner core and cladding of silica glass and plastic jackets that physically protects the fiber. There are three categories of optical fiber distinguished by their modal and physical properties and they are single mode, step index (multimode), and graded index (multimode). Single mode fiber supports higher signaling speed due to its smaller diameter and mode of light propagation. Cable installations could be underground, direct buried, under sea, or aerial. Table III shows the fiber optic cable advantages and disadvantages
TABLE III: FIPER OPTIC CABLE ADVANTAGES / DISADVANTAGES
Advantages Disadvantages
Immune to electromagnetic
interference
Immune to ground potential rise
High channel capacity
Low operation cost
No licensing required
Novel technology, i.e. new skills must be learned
Expensive test equipment
Subject to breakage and water ingress
Inflexible network configuration
Less-cost-effective, if only used for SCADA low traffic
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Security, not easy to intercept
Can span longer distances without
the need for repeaters
However, knowing that fiber optic cable is the most preferred solution for SCADA systems
due to its reliability and long distances it covers, if these high-speed channels are only used
for SCADA low traffic and not fully utilized, then these communications resources are
greatly wasted where the spare capacity is used by “nice to have” features rather than
“need to have” issues
IV. Power Line Carrier (PLC)
Power Line Carrier (PLC) was one of the first reliable communications media available to electric utilities for critical communications channels that could not be subjected to the intolerance and unreliability of leased (common carrier) telephone circuits. PLC uses the power transmission lines to transmit radio frequency signals.
Since the power system’s current carrying conductors offer a robust, reliable and economic link for power system communications, the PLC systems have been used for the applications of power system relaying and control since 1940’s. PLC systems operate in on-off mode by transmitting radio frequency signals in the 10 to 500 kHz band over power transmission lines Table IV shows the PLC advantages and disadvantages
TABLE IV: PLC ADVANTAGES / DISADVANTAGES
Advantages Disadvantages
Located where the circuits are
required, for power utilities
Equipment installed in utility owned
land or structures
Economically attractive for low
numbers of channels extending over
long distances
Dependent on the power distribution system Carrier frequencies
often not protected on a primary basis
Inherently few channels available
Will not propagate through open disconnects
Expensive on a per-channel basis
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in
the next page:
1. Discuss the advantage and disadvantage of Twisted-pair copper
2. Disuse the advantage and disadvantage of Coaxial cable
3. Describe Fiber Optic Cable
4. Discuss Power Line Carrier (PLC)
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. …………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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Instruction Sheet 3 Learning Guide 61: Make decisions using SCADA
This learning guide is developed to provide you the necessary information regarding the following
content coverage and topics
Interrogating the SCADA system to find required current, historical or predicted information
Taking actions appropriate to the information
This guide will also assist you to attain the learning outcome stated in the cover page. Specifically, upon
completion of this Learning Guide, you will be able to
Interrogate the SCADA system to find required current, historical or predicted information
Take actions appropriate to the information
Learning Instructions:
1. Read the specific objectives of this Learning Guide.
2. Follow the instructions described in number 3 to 20.
3. Read the information written in the “Information Sheets 1”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
4. Accomplish the “Self-check 1” in page __.
5. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 1).
6. If you earned a satisfactory evaluation proceed to “Information Sheet 2”. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to Learning Activity #1
7. Submit your accomplished Self-check. This will form part of your training portfolio.
8. Read the information written in the “Information Sheet 2”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
9. Accomplish the “Self-check 2” in page __.
10. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 2).
11. Read the information written in the “Information Sheets 3 and 4”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
12. Accomplish the “Self-check 3” in page __.
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13. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 3).
14. If you earned a satisfactory evaluationevaluation, proceed to “Operation Sheet 1” in page _. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to for each Learning Act
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1.1 Introduction.
SCADA is a computer-based control system used to gather and analyses real-time data from remote devices to monitor and control equipment. SCADA systems are used in a wide range of industries, including water and wastewater, power and energy, mining, food and beverage, transportation, defense, and infrastructure, among others.
The basic architecture involves programmable logic controllers (PLCs) or remote terminal units (RTUs) which communicate with, and collect data on, different types of process equipment including machinery, pumps, flow/position/level sensors and many other devices. This data is transmitted to centralized computers with SCADA software where it is processed, distributed, and displayed so that operators can analyse it to make informed decisions.
SCADA systems can be found in a large range of applications including, achieving quality standards at wastewater treatment plants, energy management for critical infrastructure, and ensuring production and safety at manufacturing facilities, to name a few.
SCADA systems are also subject to a number of national and international standards covering how the equipment is used and installed, along with functional safety. This is vital to ensure the systems are safe and reliable.
Looking at the overall makeup of a SCADA system, there are five critical components:
1.2 Human-Machine Interface (HMI)
A Human Machine Interface, or HMI, is an input-output device that has a display screen which is linked to the SCADA program and databases. It provides management information for operators such as scheduled maintenance procedures, operator controls, schematics, logistic information, and trending and diagnostic data for specific sensors and machines.
This information can then be analyzed and used to make informed decisions.
1.3 Supervisory system
The supervisory system is used to relay data from equipment such as RTUs, PLCs and sensors to the HMI or other display interfaces which are typically located in a centralized control center or and at various site locations.
Information Sheet-1 Interrogating the SCADA system and Taking actions
appropriate to the information
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Smaller supervisory systems may contain a single computer or HMI while larger systems may contain distributed software applications, disaster recovery sites and multiple servers that are configured in a redundant formation, such as hot-standby. The supervisory system continuously monitors and controls operations to maintain the safety and integrity of the SCADA system.
1.4 Remote Terminal Units and Programmable Logic Controllers
Remote Terminal Units (RTU) are electronic devices controlled by a microprocessor that are used to interface to field equipment with the SCADA system by transmitting telemetry data to the supervisory system. RTUs are also used to receive messages from the master control system which monitors and controls connected field equipment.
Programmable Logic Controllers (PLCs) are computer control systems that are connected to equipment and sensors via input and output signals which are converted into data. PLC systems are usually ‘closed’ or separate from other IT systems such as LAN, WAN or corporate networks, this ensures the integrity and safety of the control system.
1.5 Communication Infrastructure
Communication infrastructure for SCADA systems can vary between applications depending on the size and requirements of the system.
Factors that need to be considered when designing or setting up a communication network include existing communications infrastructure, budget, data protocols, speed of transmission, line of sight for radio networks, criticality (including redundancy requirements) and ability to accommodate future needs.
Communication infrastructure is essential to SCADA systems, especially in applications where assets are distributed over a large geographical area.
1.6 SCADA Programming
In order for a SCADA system to function correctly and safely, it requires thorough knowledge of not only the engineering process being monitored and/or controlled, but also the programming language and associated standards.
There are various formats used in SCADA programming, and most modern SCADA packages have their own in-built libraries consisting of icons and other visual display tools.
SCADA programming requires knowledge and experience to master as there are a lot of factors to consider. If done correctly the system will perform flawlessly for many
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years, however if installed incorrectly the system would likely become unstable, causing extensive damage including potential loss of life.
1.7 An automated advantage
“These five components play a critical part in the operation of a SCADA system. While project costs do need to be taken into account, clients should focus on the total cost of ownership for these systems,” Mr Bladon said.
“The cheapest option might not be the best if the equipment doesn’t meet standards, or if the programming is done poorly and without proper documentation. These can make a difference on the efficiency and productivity of a site, as well as the ease of future upgrades. Some lower cost options actually take a lot more engineering time to deliver the same result as what appears to be a more expensive option.
1.8 Architecture:
Generally, the SCADA system is a centralized system that monitors and controls the entire area. It is a pure software package that is positioned on top of the hardware. A supervisory system gathers data on the process and sends the commands control to the process. The SCADA is a remote terminal unit which is also known as RTU. Most control actions are automatically performed by RTUs or PLCs. The RTUs consists of the programmable logic converter which can be set to specific requirement. For example, in the thermal power plant, the water flow can be set to a specific value or it can be changed according to the requirement.
The SCADA system allows operators to change the set point for the flow, and enable alarm conditions in case of loss of flow and high temperature, and the condition is displayed and recorded. The SCADA system monitors the overall performance of the loop. The SCADA system is a centralized system to communicate with both wired and wireless technology to Clint devices. The SCADA system controls can run completely all kinds of the industrial process.
EX: If too much pressure is building up in a gas pipeline the SCADA system can automatically open a release valve.
Hardware Architecture:
The generally SCADA system can be classified into two parts:
Client layer Data server layer
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The Clint layer which caters for the man-machine interaction.
The data server layer which handles most of the process data activities.
The SCADA station refers to the servers and it is composed of a single PC. The data servers communicate with devices in the field through process controllers like PLCs or RTUs. The PLCs are connected to the data servers either directly or via networks or buses. The SCADA system utilizes a WAN and LAN networks, the WAN and LAN consist of internet protocols used for communication between the master station and devices. The physical equipment like sensors connected to the PLCs or RTUs. The RTUs convert the sensor signals to digital data and sends digital data to the master. According to the master feedback received by the RTU, it applies the electrical signal to relays. Most of the monitoring and control operations are performed by RTUs or PLCs as we can see in the figure.
Fig 1.1 monitoring and control operations by RTUs or PLCs
1.9 Working Procedure of SCADA system:
The SCADA system performs the following functions:
Data Acquisitions Data Communication Information/Data presentation Monitoring/Control
These functions are performed by sensors, RTUs, controller, a communication network. The sensors are used to collect the important information and RTUs are used to send
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this information to the controller and display the status of the system. According to the status of the system, the user can give the command to other system components. This operation is done by the communication network.
I. Data Acquisitions:
The real-time system consists of thousands of components and sensors. It is very important to know the status of particular components and sensors. For example, some sensors measure the water flow from the reservoir to the water tank and some sensors measure the value pressure as the water is a release from the reservoir.
II. Data Communication:
The SCADA system uses a wired network to communicate between users and devices. Real-time applications use a lot of sensors and components which should be controlled remotely. The SCADA system uses internet communications. All information is transmitted through the internet using specific protocols. Sensor and relays are not able to communicate with the network protocols so RTUs used to communicate sensors and network interfaces.
III. Information/Data presentation:
The normal circuit networks have some indicators which can be visible to control but in the real-time SCADA system, there are thousands of sensors and alarm which are impossible to be handled simultaneously. The SCADA system uses the human-machine interface (HMI) to provide all of the information gathered from the various sensors.
IV. Human-machine interface:
The SCADA system uses the human-machine interface. The information is displayed and monitored to be processed by a human. HMI provides access to multiple control units which can be PLCs and RTUs. The HMI provides the graphical presentation of the system. For example, it provides a graphical picture of the pump connected to the tank. The user can see the flow of the water and the pressure of the water. The important part of the HMI is an alarm system that is activated according to the predefined values.
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Fi 1.2 gexample of SCADA system graphical display
For example, The tank water level alarm is set 60% and 70% values. If the water level reaches above 60% the alarm gives a normal warning and if the water level reaches above 70% the alarm gives a critical warning.
V. Monitoring/Control:
The SCADA system uses different switches to operate each device and displays the status of the control area. Any part of the process can be turned ON/OFF from the control station using these switches. SCADA system is implemented to work automatically without human intervention but in critical situations, it is handled by manpower.
The SCADA acronym stands for Supervisory Control and Data Acquisition. When considering this term, you can conjure varying images and you should.
A SCADA system is a collection of both software and hardware components that allow supervision and control of plants, both locally and remotely.
The SCADA also examines, collects, and processes data in real time.
Human Machine Interface (HMI) software facilitates interaction with field devices such as pumps, valves, motors, sensors, etc.
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Fig 1.3 SCADA control system
Also within the SCADA software is the ability to log data for historical purposes.
The structural design of a standard SCADA system starts with Remote Terminal Units (RTUs) and/or Programmable Logic Controllers (PLCs).
As you know, RTUs and PLCs are microprocessors that communicate and interact with field devices such as valves, pumps, and HMIs.
That communication data is routed from the processors to the SCADA computers, where the software interprets and displays the data allowing for operators to analyze and react to system events.
Before SCADA, plant personnel had to monitor and control industrial processes via selector switches, push buttons, and dials for analog signals.
This meant that plants had to maintain personnel on site, during production, in order to control the processes.
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Fig 1.4 controlling & monitoring with out SCADA system
As manufacturing grew and sites became more remote in nature, relays and timers were used to assist in the supervision and control of processes. With these devices employed, fewer plant personnel were required to be on site in order to oversee and control operations.
While relays and timers did provide some level of automation, the panels required for these devices took up valuable real estate, troubleshooting was a nightmare, and reconfiguring was difficult at best.
These issues, in conjunction with the need to grow even larger industrial plants, helped to facilitate the birth of automation
The main purpose of SCADA monitoring is to streamline the gathering, monitoring and analyzation of all production data. This is so engineers, managers and operators can make decisions to improve production, efficiencies and operations. Last week, we mentioned the three SCADA questions that plant managers and continuous improvement leaders should ask. This blog post continues by answering the questions. Will it improve my yield?
When implementing SCADA, managers and operators expect to gain comprehensive insights about the production processes. Of course, the priority benefit of these insights is to improve yield. However, calculating yield often depends upon the criteria used. And many companies look at criteria differently. Some focus on what was used and expected at the start of the production process and compare it to the number of successful finished units. Others look at production results and successes at different stages throughout the entire production process.
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The key is to have a good view into historical production and production performance. An integrated SCADA solution allows for thorough historical data searches and management of the performance information. As well, the SCADA should help employees quickly comprehend the analysis and insights from that historical data.
To improve yield, focuses on driving information related to three critical areas:
Reducing the amount of raw material needed, i.e. reduce waste in process Avoiding mistakes that cause a batch to go bad or be defective, i.e. avoid poor
quality Reusing existing finished goods and pass them again through the process
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in the
next page:
1. Explain Human-Machine Interface (HMI)
2. Explain Supervisory system
3. Explain Remote Terminal Units and Programmable Logic Controllers
4. Explain Communication Infrastructure
5. Explain the main purpose of SCADA monitoring
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. …………………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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Instruction Sheet 4 Learning Guide 62: Monitor the use of SCADA
This learning guide is developed to provide you the necessary information regarding the following
content coverage and topics
Routinely monitoring SCADA information
Identifying poor uses of SCADA system within team and system inadequacies
Identifying system improvements required
Taking appropriate action to improve SCADA system and its use
This guide will also assist you to attain the learning outcome stated in the cover page. Specifically, upon
completion of this Learning Guide, you will be able to
Routinely monitor SCADA information
Identify poor uses of SCADA system within team and system inadequacies
Identify system improvements required
Take appropriate action to improve SCADA system and its use
Learning Instructions:
1. Read the specific objectives of this Learning Guide.
2. Follow the instructions described in number 3 to 20.
3. Read the information written in the “Information Sheets 1”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
4. Accomplish the “Self-check 1” in page __.
5. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 1).
6. If you earned a satisfactory evaluation proceed to “Information Sheet 2”. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to Learning Activity #1
7. Submit your accomplished Self-check. This will form part of your training portfolio.
8. Read the information written in the “Information Sheet 2”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
9. Accomplish the “Self-check 2” in page __.
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10. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 2).
11. Read the information written in the “Information Sheets 3 and 4”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
12. Accomplish the “Self-check 3” in page __.
13. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 3).
14. If you earned a satisfactory evaluationevaluation, proceed to “Operation Sheet 1” in page _. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to for each Learning Act
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1.1 Introduction
The monitoring system is a real time supervision system of the field devices real time status (currents, voltages, pressures, temperatures, contacts, etc.). This supervision is made through digital equipment and special sensors that are installed in the field devices of the substation. The data are collected and processed in a data acquisition and control unit (UAC), to thereafter through a communication network, using desirably a protocol standardized internationaly,be sent to a central computer located at the control building of the substation and later to the operation centers and so allowing a remote supervision
1.2 SCADA System Monitoring
Supervisory Control and Data Acquisition (SCADA) systems are an integral part of every energy operation. Communication devices and SCADA connectivity solutions enable cost-effective monitoring and remote management of critical equipment, in some of the most remote areas of the world.
Communication satellites enables the collection of equipment data from remote SCADA sites and converts it into actionable intelligence using cost-effective and reliable satellite and cellular communications. This makes it easier to reduce maintenance costs and site visits, minimize downtime and maximize output of a variety of critical equipment.
Gain Full Visibility of Remote SCADA System Sites
Monitor and control critical SCADA system equipment with full visibility from a central location via reliable, always-on connectivity.
Connect remote, orphan sites, where connectivity is otherwise unavailable, unreliable or cost-prohibitive.
Enhance production by enabling more efficient and cost-effective collection of critical operations data.
Reduce Maintenance Costs and Equipment Downtime
Lower operations costs by enabling preventative maintenance with regular equipment monitoring.
Reduce downtime and production losses with early fault detection and quick response time.
Extend connectivity to sites without the cost of upgrading legacy SCADA system equipment.
Information Sheet-1 monitoring SCADA information
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Increase Efficiency and Reduce Site Visits
Reduce labor, vehicle and fuel costs with process automation requiring fewer routine and emergency visits to remote sites.
Deliver alarms and event notifications based on user-defined thresholds and criteria.
Evolve from the use of auto dialers to a more comprehensive way of managing remote SCADA sites.
Connect to Remote PLCs and RTUs
Provide connectivity between remote SCADA PLCs and the Human Machine Interface (HMI) system using edge analytics to send only relevant information.
Streamline operations by using edge analytics to collect and analyze field data locally.
Bridge the communications gap between RTUs and IP-based SCADA control systems.
Support industry-standard protocols such as Modbus and OPC. SCADA can be boiled down to the following: an integrated system to monitor,
gather and process data from all critical machines within a production environment. But it is easy to see how the core purpose for SCADA gets a little clouded in today’s graphical, web-driven, data-intense world. SCADA is a noun, but plant managers should think of SCADA as a verb. SCADA is a series of actions all poised to drive towards a result and purpose.
We see two key factors as steering away from SCADA’s original intent: Data Volume and Rich Graphics.
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Data Volume:The overwhelming opinion for SCADA is that it needs more and more
data. Most companies and managers are thinking “We need to collect data or more
data.” They see data is the key. But data is the resource, not the result. Data is not the
driver or the vehicle… it is the fuel. Just having more of something does not mean you
will know what to do with all of it to get what you really need from it.
Rich Graphics:Dashboards. That is another aspect of today’s SCADA thinking that can
get in the way of a successful monitoring or SCADA project. Graphics and reporting and
visuals are cool. The data that is gathered does need to be analyzed and presented in
an easily digestible format. Dashboards are not bad, but let’s make certain that the data
presented is information you can use… is actionable information. Information that helps
generate better decisions.
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet
provided in the next page:
1. Explain Human-Machine Interface (HMI)
2. Explain Supervisory system
3. Explain Remote Terminal Units and Programmable Logic Controllers
4. Explain Communication Infrastructure
5. Explain the main purpose of SCADA monitoring
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. ………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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2.1 Poor uses of SCADA system within team and system inadequacies
Basic troubleshooting of the various components of a telemetry system will be given for poor uses of SCADA system
This includes the following:
1. The RTU and component modules a. Associated equipment interfaced to the RTU (such as PLCs) b. Radio transceivers c. Antennas and antenna feeder systems
2. The master station 3. The central site computer facilities 4. The operator station and software
IMPORTANT NOTES //
Ensure that components are not removed on line whilst the system is powered up unless the manufacturer specifically indicates that this is permissible. Damage to components and modules can occur when removing whilst the system is still powered up.
Ensure that the antenna system is not disconnected from the system unless a dummy load has been installed, otherwise the radio power amplifier may be damaged.
2.2.1 The RTU and component modules
A typical procedure to follow when reviewing the operation of the telemetry system for faults (either for intermittent or outright failure) is:
Confirm that the power supply module is healthy. Check the main fuse or circuit breaker of the equipment rack or unit if no power is evident.
If the power supply is not operating, check that there is power to the power supply module. If there is power to the module then replace the power supply module.
Check central processing (CPU) module that the run or healthy light is on. Switch the CPU module to run mode if not running.
Check earthing connections for low resistance to earth or whether some other drive hardware (such as a variable speed drive) has been added to the system.
If CPU module will not run, check the configuration program to see whether this is faulty or not. Reload the program if indications are that it has become corrupted. Check that the configuration of the system matches that of the hardware.
Information Sheet-2 Identifying poor uses of SCADA system within team and
system inadequacies
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Figure 2.1– Troubleshooting the overall system telemetry
Load up a simpler program that you know works, if the program is possibly defective.
Back up defective program onto disk (for future analysis) and reset the memory.
Cycle power to the RTU before the new program is loaded. Replace the CPU and retry the test. Check that the modem module is operating. Confirm that the modem is operational and
that it is transmitting and receiving data by examining the transmit (TX) and receive (RX) lights on the front panel.
If the modem is not operational, replace the modem module (or desktop unit). If the modem module is not operating correctly, perform the local and remote loopback
tests as described in the modem section.
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Check each analog and digital input/output module for status such as healthy or run. Check for possible heating problems in the system cabinet. This could be due to failure of an air-conditioning or fan unit (if installed) or excessive
ambient temperature. If a module indicates no power at all – check the fuse for that module. Replace each module if the indications are not healthy.
Fig Troubleshooting of a telemetry system (from RTU to the SCADA computer facilities)
Effective troubleshooting of a telemetry system
This technical article reviews certain methodologies that may be followed for effective troubleshooting of a telemetry system from the digital or analog field input/output at the RTU to the computer facilities at the central site.
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fig
Troubleshooting of a telemetry system (from RTU to the SCADA computer facilities)
Check each individual module as follows:
Analog input modules
Check that there is current or voltage being injected into the signal inputs. Check the fuse is installed. Check the scale and span and compare with the appropriate register tables for
accuracy. Adjust scale and span either via software or via pots on the card.
Digital input module
Check that there is current or voltage at the signal input to the module. Check the fuse for each input. Check earthing connections.
Interface from RTU to PLC
Check for the transmit/receive/run lights on the interface unit. Check interface data communications link.
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Check that the radio unit is operating (if used). The on light should be on and no fault lights should be on.
If the on light is not on, check that there is DC power to the radio. If there is power, check that the fuse or circuit breaker is healthy.
Check that all coaxial connectors are secured properly. Check that the PTT – Push to talk (transmit) light on the radio comes on when the
telemetry unit feeds data into it for transmitting. Check that there is sufficient audio level into the transmitter.
Check that the mute (receive) light on the radio comes on when the radio receives RF data. Check that there is sufficient audio level into the telemetry unit from the receiver.
Check that the voltage standing wave ratio into the antenna is 1.5 or less. Check that the RF output power from the transmitter is as specified. Check that the antenna is aligned in the correct direction and with correct polarization. If the radio is still not working correctly, a radio test set will be required to check
transmitter deviation, RF distortion, audio distortion, receiver sensitivity at 12 dB SINAD, transmitter and receiver frequency errors, transmitter/receiver isolation and transmitter spurious outputs.
If a landline is to be used, then first ensure that the telemetry and modem equipment is operational.
Then if the line is a:
Privately owned cable
Check for end to end connectivity Measure noise level on line Check for crossed pairs Check main distribution frame (MDF) and intermediate distribution frame (IDF)
connections Check earthing
Switched telephone line
Listen for dial tone Connect up a standard telephone and make a normal telephone call Listen for noise levels Call out the telephone company
Analog or digital data links
Check the run, connect, transmit and receive lights on the modem Check the operations manual and the communications software Call out the telephone company
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2.2.2 The master sites
The master sites will generally consist of a more complete telemetry unit and higher quality radio equipment. The same troubleshooting techniques can be applied to the master site as are used at the RTUs. Additional equipment would include links to other master sites, to the central site and computer control facilities.
The additional checks that will be appropriate include:
1. Check that the link to the central site is operating correctly. 2. If it is a radio link, carry out the check as discussed in the last section. 3. If it is a microwave link, check that the transmit and receive lights are on. 4. Check that the BER alarm light is not on. 5. Check transmit power. 6. Check receiver sensitivity. 7. Check antenna alignment. 8. Check connectors are secure and the cable or waveguide has not been damaged. 9. Check individual multiplex cards for alarms and power fails. 10. Check input/output levels from multiplex cards. 11. Check for clean (noise free) healthy power supply to microwave equipment. 12. Check link fade margin. 13. As a last resort, carry out BER tests on each channel. 14. If there is a master site computer, check that it can carry out all its required functions,
i.e. monitoring of radio and RTU performance, status and alarms, etc.
2.2.3 The central site
The areas in which to troubleshoot problems here are quite varied as the master station consists of:
1. The operator stations 2. The software for the system 3. The communications network for the operator stations
The radio and the antenna systems have already been covered in the previous section. However the operator stations, the communications network and the associated software will be covered in this section.
2.2.4 The operator station and software
There is not much that can be done here if a system fails or has intermittent problems except to systematically replace each connected unit to identify the faulty module.
This would typically involve replacing the following units in turn:
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Operator terminal (normally a personal computer) Local area network card(s) Bridge unit to radio, microwave or landline system Printer connected to operator terminal
There are however a few problems which can be examined:
Operator terminal locks up intermittently Check the power supply to the system for possible electrical spikes or transients. This
can be done with power analysis equipment (e.g. the dranetz) or by putting the entire system onto a battery supply.
Check for any new electrical drives or pieces of equipment, which have recently been added to the system (and which may add harmonics to the system).
Check the earthing cable connections that the impedance to earth is still to specifications (typically less than 1 ohm).
Do a software check on the hard disk of the operator terminal for possible corruption of software or failure of the disk. Backup the system, reformat the hard disk and reinstall the software on the disk.
Replace the motherboard on the operator terminal (this probably indicates that the operator terminal should be replaced with another system).
Throughput of the operator station and associated system drops off dramatically This manifests itself in slow updates of data on the operator terminal. Check the system for errors being introduced on the data communications lines by
electrical noise or earthing problems. The data communications system could be sending multiple messages due to errors introduced by electrical noise.
Check the local area network for potential overload due to excessive traffic. Reduce the traffic by reducing the amount of data being transferred or split the systems up into separate networks (using bridges).
Check the radio, microwave, landline, and antenna systems for possible introduction of noise and error problems.
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in
the next page:
1. Write the typical procedure to follow when reviewing the operation of the telemetry system for faults
2. Troubleshooting of a telemetry system
I Analog input modules
II Digital input module
3. Write troubleshooting procedure for the master sites
4. What the areas in central site to troubleshoot problems
5. What are the units which require replacement in operation station
6. Explain the main purpose of SCADA monitoring
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. ………………………………………………………………………………………………………
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5. ………………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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3.1 Introduction
Supervisory Control and Data Acquisition, or SCADA, is a hardware and software system used to monitor and automate the control of industrial processes and machines. For many manufacturers and municipalities, SCADA systems are a critical component of the overall production process and are required to be secure, efficient, and capable of performing all necessary tasks. Over time, a SCADA system can become outdated and unsupported, lack functionality and features, present security risks, and be difficult to scale. These are the four reasons why you should upgrade your SCADA system:
3.2 System Support and Compatibility
An outdated SCADA system will often be unsupported by the manufacturer and be incompatible with modern controls hardware. Without manufacturer support, an outdated SCADA system will no longer receive necessary security patches or system updates, which can lead to extended downtimes during equipment failures, and a higher risk for cyber-attacks. Additionally, it can be challenging to find replacement parts for the outdated controls hardware, as well as increasingly expensive.
3.3 Unlock Greater Functionality and Features
Older SCADA systems may not have the same level of functionality and features that a new SCADA system can offer. For example, modern SCADA systems include improved graphics that provide more contextual information and greater situational awareness while reducing distractions by eliminating busy interfaces and animations in favor of intuitive and clean displays.
Additionally, a new SCADA system will often have increased connectivity and allow for integration with complementary programs, such as an ERP system, CRM, SQL databases, and modern HMI software. Finally, technological advances and processing improvements provide the opportunity to future proof your systems and incorporate IIOT data, machine learning, and artificial intelligence capabilities into your manufacturing.
3.4 Improve System Security
Outdated SCADA systems are vulnerable to data invasions, and likely can’t comply with newer security standards, such as encryption, two-step authentication, and secure remote access. SCADA security has drastically improved in recent years to reduce or eliminate both physical and cyber vulnerabilities. Upgrading to a modern SCADA system will allow you to take advantage of the new security capabilities and ensure you are protected from attacks.
3.5 Scalability and Future Proofing
Modern SCADA systems can be developed using object-oriented programming. This programming technique entails a template-based system design with easily manageable blocks of code representing various objects or equipment. As your manufacturing grows, new code blocks can be added quickly and inexpensively,
Information Sheet-3 Identifying system improvements required and taking action
to improve SCADA system and its use
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allowing your SCADA system to grow with you. Furthermore, once a system template has been created, it can be copied and reused for each new facility, significantly reducing development time and costs.
Initial planning: Determine which systems will be upgraded, in
what order and why. Think through how systems affects other systems.
Create a testing plan. Shift coverage: Oftentimes, during low-flow conditions in the evenings, it is easier
to make changes. Because night shifts do not typically have as many people around, plants may need to add personnel.
Training plan: All shifts and the maintenance crew need to learn about system changes and new information.
Seasonal impact: When it comes time to implement some changes, plants need to consider how weather will affect the process. Depending on the geography, there could be rainy seasons, dry seasons or snow. Some aspects of the upgrade may need to be deferred to a certain time of the year. Activated sludge processes, for example, are biologically controlled. High water and cold weather can have major impacts, and it is difficult to make a change without upsetting the plant. Storms also should be considered. If a storm passes through, it could throw plans off for a few weeks. The project plan needs to be flexible.
Coordination with other ongoing or future projects: Oftentimes there are projects that are seemingly unrelated, but could run into each other and negatively impact progress.
Update IT structure, security, credentials and authorization levels: Some of these may not have been changed for years. Today, there are new standards, methods and philosophies surrounding things like access
Offsite testing: Perform offsite tests of graphics, navigation, etc. Onsite installation and testing with plant operators: If operators are involved in
development, this step will go more smoothly. Operators know how the plant works, so they can determine whether the new system is working the way it should.
Parallel operation with the old system: This should run for a defined period, and it usually takes a couple of weeks. It can be beneficial not to completely rely on the new system, because there likely will be bugs that need to be worked out, and an upset can have a major impact.
Keep the old system: Even after turning off the old system, maintain access in the
event something was missed. This is especially true for weather events that are
difficult to test for.
Keys to Success
Take the lessons learned from each system upgrade and repeat for subsequent
systems, building on them for the next increment.
Remember to create a sense of collaboration, not confrontation, with the systems
integrator. Incremental upgrades can take longer, so seasonal events and unforeseen
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issues may arise as the project progresses. Everyone needs to be flexible and work
together to overcome these challenges.
It is important to plan for remote access to the plant system through VPN or other
secure means. This is especially true for those “things that go bump” in the night and on
the weekend. It allows the systems integrator to get online quickly, rather than having to
drive to the site before he/she can respond, saving everyone headaches and time.
Plants may be apprehensive to allow such access because of concerns about cyber
terrorism, but it can be done securely, and is a major key to success and more efficient
than having the technicians on site when it is not necessary. Your integrator should be
able to establish secure VPNs through its own system
Improving Efficiency and Security
Increasing the efficiency of a business and the security of a SCADA system both require increased monitoring.
Increasing the security requires more than removing access to the system from the Internet!
Increased monitoring with greater security creates various challenges to SCADA system users and system vendors that include:
Managing larger data traffic loads due to increased monitoring of local and remote assets,
Implementing standby/backup servers and communications links for critical system infrastructure,
Securing the communications traffic between various devices and users,
Restricting and authenticating access to both the system and the field assets,
Management of on-line configuration processes to avoid induced system errors (most system failures occur when system maintenance/upgrades are being deployed),
Managing the collected data for display, storage and access by users and other business systems, including event/alarm escalation (important events must receive attention promptly).
As an example, it is no longer acceptable to simply monitor the level of a suburban water reservoir to be assured that the operational state is normal. Now the SCADA system monitoring must also include the physical security of the location - using video surveillance and intruder detection, the water quality - using online analyzers, the time in storage (age of the unused water) - to avoid bacterial contamination, and the ‘health’ of the communications link and field equipment.
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in
the next page:
1. What are the four reasons why you should upgrade your SCADA system?
2. Why you improve system security?
3. What is the benefit of Improving Efficiency and Security
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
1. …………………………………………………………………………………………………
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5. …………………………………………………………………………………………………
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Score = ___________
Rating: ____________
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Instruction Sheet 5 Learning Guide 63: Support team use of SCADA
This learning guide is developed to provide you the necessary information regarding the following
content coverage and topics
Regularly communicating with team, both using SCADA-based communication and face to face
Identifying skill improvement needs
Identifying team members who require additional support
Taking appropriate action to provide support
This guide will also assist you to attain the learning outcome stated in the cover page. Specifically, upon
completion of this Learning Guide, you will be able to
Regularly communicate with team, both using SCADA-based communication and face to face
Identify skill improvement needs
Identify team members who require additional support
Take appropriate action to provide support
..
Learning Instructions:
1. Read the specific objectives of this Learning Guide.
2. Follow the instructions described in number 3 to 14.
3. Read the information written in the “Information Sheets 1”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
4. Accomplish the “Self-check 1” in page __.
5. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 1).
6. If you earned a satisfactory evaluation proceed to “Information Sheet 2”. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to Learning Activity #1
7. Submit your accomplished Self-check. This will form part of your training portfolio.
8. Read the information written in the “Information Sheet 2”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
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9. Accomplish the “Self-check 2” in page __.
10. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 2).
11. Read the information written in the “Information Sheets 3 and 4”. Try to understand what are being discussed. Ask you teacher for assistance if you have hard time understanding them.
12. Accomplish the “Self-check 3” in page __.
13. Ask from your teacher the key to correction (key answers) or you can request your teacher to correct your work. (You are to get the key answer only after you finished answering the Self-check 3).
14. If you earned a satisfactory evaluationevaluation, proceed to “Operation Sheet 1” in page _. However, if your rating is unsatisfactory, see your teacher for further instructions or go back to for each Learning Act
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1.1 Introduction
The supervisor is in a unique position, serving as the link between management and the workforce. Senior management articulates the vision, middle management devises the strategy, and the supervisor has to ensure that the workforce performs the work. To accomplish this, the
supervisor has to be able to effectively communicate with the workforce.
To function effectively within the organization, the supervisor also has to be able to effectively communicate horizontally as well as vertically (see Figure 1). People in organizations spend over three-quarters of their time in some form of interpersonal situation. Poor communication skills carry a great deal of liability. Employees and especially supervisors who do not communicate effectively are at a disadvantage and do not do thrive in organizations.
Figure 1.1: Communication Flow
Though we have been communicating with others from a very early age, the process of transmitting information from one person to another is complex. Research has found that there is erosion of meaning in the neighborhood of 40–60 percent in the transmission of information from one person to another. Given the above, it is not surprising that a substantial number of interpersonal issues, performance problems, and misunderstandings have their roots in poor
Information Sheet-1 Regularly communicating with team
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communication. So it is critical to appreciate, understand, and be aware of the potential barriers to effective communication.
1.2 The Basics
Language is a means and an important factor in our communication. It is used to convey and exchange ideas and meaning, to talk to people, and to express thoughts. It is the vehicle that helps the people with whom we are trying to communicate clearly understand the message being conveyed. The choice of words or language used in the message will influence the quality of communication. So the words used may have to be chosen with the different recipients in mind. Are the words used easy to understand by the recipient? Is the phrasing easy to grasp? Is descriptive language used? Is the ultimate message clear? By thinking about the end result—that is, what happens once you finish speaking—you can choose the words you'll need and decide how to use them to ensure that the desired outcome is achieved.
Research has shown that listeners have to put together what is being said with how it is being said in order to fully understand what is being conveyed. Effective basic communication has six elements: the sender, the receiver, the channel, contextual factors, the message itself, and feedback (see Figure 2). For communication to be effective, the supervisor must understand and manage the potential variables that may affect these elements.
Figure 1.2: The Two-Way Communication Model
Sender: (source) the person trying to communicate information, provide direction, establish performance, give feedback, etc. How the supervisor communicates affects the relationship with the workforce.
Receiver: (destination) the person receiving the message and trying to understand it. The relationship the worker has with the supervisor affects how that worker views the information and reacts to it.
Channel: The communication channels can be formal, informal, or unofficial; personal or impersonal; and active or static. The communication method (or channel) selected should depend on the type of message or its content. Before choosing which method to use, consider whether the message is interactive or static and whether it is best suited for personal or impersonal transmission. Each of these impacts the quality of the exchange.
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Interactive is a two-way communication. It allows for a discussion (back and forth). Static is a one-way communication. The receiver cannot provide immediate feedback.
The question is whether the communication should be one-way or two-way. What does your message require? You also need an understanding of the potential challenges with which the recipient may have to deal, what the recipient may need to be able to effectively carry out the instructions, etc.
Personal communication means a conversation, which needs to be face to face or by phone.
Impersonal communication is in some form of writing.
Does your communication require you to hear or see the other person? Are you trying to build a relationship or improve rapport? Will the tone of voice be important for this particular message or case? Is the information or idea potentially confusing to the recipient?
The communication channel becomes richest (see Figure 3) when the human element is a part of the exchange.
Face-to-face or personal communication is one of the richest channels of communication that can be used within an organization. The physical presence, the tone of the speaker's voice, gestures, posture, and facial expressions help the recipient(s) of a message to interpret that message as the speaker intends it. This is the best channel to use for complex or emotionally charged messages, because it allows for interaction between speaker and recipient(s) so as to clarify ambiguity. A speaker can evaluate whether an audience has received the message as intended, ask or answer follow-up questions, and provide clarification as required. The more complicated the message is, the richer the channel should be. When the message is routine and easy to understand, a lean channel is more appropriate.
Figure1.3: Communication Channels
Message: The message is the information being transmitted. The message can be verbal and/or nonverbal. To reduce potential problems, the senders should use appropriate words and a clear, straightforward structure; provide all the necessary and relevant information so that it is easily
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understood; etc. This requires the sender to have some idea of the capabilities of the recipient to understand it and to have the motivation to respond to it affirmatively.
Feedback: The only way the sender can determine that the message was received and understood is to get some form of confirmation from the receiver. This can be in the form of acknowledgment, parroting, or paraphrasing. If there is some misunderstanding or there are barriers to the receiver's ability to respond affirmatively to the information in the message, the sender needs feedback to identify the possible barriers involved. This may require a few exchanges in order to resolve the issue.
Context: The circumstances surrounding our communication play a part in determining its success or failure. Although many types of situations affect the messages we send, one particular type that can easily distort our messages is communication under stress. Stress, by its very nature, makes it difficult for us to "think clearly." In a stressful situation, the meaning of the message can be distorted; subtle shades of meaning can be confused; pieces of information can be missed or forgotten; minor points may seem more important than major ones. In addition, the wording or structure of the communication may suffer. Uncertainty, nervousness, and confusion can creep into the speaker's voice, resulting in a less assertive statement.
1.3 Barriers to Communication
Successful communication involves getting the point across to another person. Many barriers to communication exist in any organization, which detract from its effectiveness. This can be more pervasive in the construction industry due to a number of unique elements. These barriers can be environmental, situational, or personal.
Physical barriers can prevent or hinder individuals from engaging in effective communication. A host of these barriers can be present in the general area and adversely affect the exchange. They include closed doors, walled-in offices, physical distance, and/or physical discomfort. The area can be noisy or crowded. If the conversation occurs outdoors, the weather conditions may have some form of impact as well.
Culture can have a significant impact on communication. Organizational culture is created by the leadership of the organization and can become ingrained into the very fabric of the way things are communicated and business is done on a day-to-day basis. Some organizational cultures are open and supportive of input from employees and a two-way flow of information. Other cultures are more top-down—where leaders convey messages but don't seek input from staff or other stakeholders. Some cultures create workplace climates that impede people from expressing what they feel, which causes them to say only what they think is expected of them. Organizational leadership needs to be cognizant of what information needs to be shared, when it should be shared, and what process should be used to share information. When employees don't have all the information, the "grapevine" is activated, usually to the detriment of the organization.
Bias: Whether we recognize it or not, all people suffer from various biases. These biases can interfere with communication when we are sending or receiving messages. Biases can be based on our preconceived beliefs or on impressions we form about people as we interact with them. When communicating with others, it's important to be aware of and to work at overcoming these biases.
Misinterpretation occurs more often than not. When interacting with others, we sometimes jump to conclusions or misinterpret what is being said. As a result, our response to the message may further impede the effectiveness of the exchange. So it is important to ensure that the message is clear and that the recipient understands it as we intended.
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Role conflicts can create barriers to communication in organizations. Regardless of how open managers and senior leaders believe they are to employee input, employees are often hesitant to share their honest insights, especially when those insights may be perceived as critical of management. This particular issue is more problematic for larger organizations than smaller ones, since these tend to be less formal and bureaucratic.
Other barriers deal with people's perceptions, emotions, and attitude; a lack of communication skills; a lack of knowledge or interest; inability to use language effectively; or the timing of the message. Other factors may involve the selection of the communication channel or the effectiveness of the technology. Most barriers occur at the interfaces within the communication process (see Figure 4). This may be caused by how the sender structures the message or how the receiver interprets it. We do not always effectively communicate what we are thinking or intending to say. Communication failures arise when there is a gap between what the sender meant and what the receiver thought the sender meant.
Figure 1.4: Communication Barriers
Some examples of the causes of communication failure:
Being so preoccupied that you don't listen to what others are saying Being so sure of the importance of what you have to say that you fail to listen, instead
breaking in to voice your thoughts Assuming that you know what the other is going to say and breaking in to voice your
response Listening with a closed mind and therefore discounting the content of the message Being so focused on the words that the emotional aspect of the message is missed Discounting what is being said due to mistrust of the speaker
All of these barriers can be overcome by conscious effort
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet provided in the
next page:
1. What are the potential variables that may affect effective communication
2. What are Barriers to Communication
3. Write five examples of the causes of communication failure
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
Rating: ____________
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2.1 Introduction
Most managers know that training is essential for team success. But many don't take
the time to understand team members' individual needs, even though it is the only way
to ensure that their people have the skills and knowledge they need to perform well and
meet their objectives.
However, how do you know who needs what training? And how do you avoid wasting
time and money on unnecessary training activities? In this article we'll explore the
importance of understanding your people's developmental needs, and we'll look at a
process that you can use to do this effectively.
2.2 Understanding Individual Developmental Needs
Clearly, some training needs will be universal, and will apply to many, if not all, of your
team members. However, everyone on your team is unique; they have different skills,
different levels of understanding, and different responsibilities and objectives.
Therefore, training and development shouldn't follow a "one size fits all" approach if you
want it to be effective. Instead, you need to take the time to understand the training that
each individual needs, so that you can provide the right training for the right people. As
well as improving performance, this saves time, resources, and money.
With this tailored approach, your people will also feel more empowered, and they'll be
able to link what they learn to their own personal objectives. This boosts well-being and
morale.
2.3 How to Develop People in the Workplace
The six steps below, which we've adapted from the American Society for Training and
Development's Strategic Needs Analysis, will help you better understand people's
training needs:
1. Review team members' job descriptions.
2. Meet with them.
3. Observe them at work.
4. Gather additional data.
5. Analyze and prepare data.
6. Determine action steps.
Let's look at each step in greater detail.
Information Sheet-2 Identifying skill improvement needs
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I Review Team Members' Job Descriptions
Start by thinking about what work your team members should be doing – this will be
defined by their job descriptions . Identify the skills that they may need to do things
well.
Tip: Job descriptions can get out of date. Before using them to think about training, ensure that they fairly reflect what individual team members actually do.
II Meet With Team Members
Your next step is to meet one-on-one with each member of your team. Your goal here is
to have an open talk about the kind of training and development that they think they
need to work effectively and develop their career.
They might not feel that they need any training at all, so it's important to be up front
about your discussion. Use your emotional intelligence , as well as good questioning
techniques and active listening , to communicate with sensitivity and respect.
Ask the following questions to get a better understanding of your people's training
needs:
What challenges do you face every day?
What is most frustrating about your role?
What areas of your role, or the organization, do you wish you knew more about?
What skills or additional training would help you work more productively or
effectively?
Then, talk to them about what they would like to get out of additional training, and ask
them to visualize the outcomes that they'd like to achieve. What does this future look
like to them?
Also, find out more about their personal goals , and think about how well these goals
align with the organization's objectives . Ideally, training and development will help
them in both of these areas.
Tip 1: You can pick up some important clues about people's needs by observing their body language . For instance, if they start to fidget and lower their eyes when you talk about their computer skills, it could indicate that they don't feel comfortable in this area.
Tip 2: You may find it easier to incorporate this step into a feedback session or appraisal.
III Observe Team Members at Work
Next, keep an eye on how well your team members are doing with key tasks. (If
appropriate, use an approach like Management by Walking Around to do this.)
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For instance, could they be quicker with key tasks, or are they procrastinating on
projects? This might indicate that they're not confident in their abilities, or are not
sufficiently well trained in key skill areas.
Try to be fair and straightforward when you do this. If team members know that you're
watching them, they might act differently, but if they discover that you're watching
secretly, it could damage the trust they have in you. So be sensitive, ask open
questions, and, where appropriate, explain your actions.
Tip: Once you've observed people working, it can be useful to confirm your assessment by setting specific, time-bound tasks that give them the opportunity to demonstrate their skills and abilities. Do this positively, though – don't set people up to fail.
IV Gather Additional Data
If you approach data gathering in a sensitive way, you can learn a lot from others who work
closely with the person you want to assess.
These people could include internal or external clients, past bosses, or even peers and
co-workers.
Remember the following while gathering information from these sources:
Make sure that you don't undermine the person's dignity, and that you respect
the context. For example, in some cultures, it may be acceptable to talk openly to co-
workers. In others, you will have to do this with a lot of sensitivity, if you do it at all.
Avoid unfocused generalizations. Ask people to back up their comments with
specific examples.
You can also use information from past appraisals or feedback sessions.
V Analyze and Prepare Data
Now, look closely at the information you gathered in the first four steps. What trends do
you see? What skills did your team members say they needed? Are there any skills
gaps?
Your goal here is to bring together the most relevant information, so that you can create
a training plan for each team member.
VI Determine Action Steps
By now, you should have a good idea of the training and development that each person
on your team needs. Your last step is to decide what you're going to do to make it
happen.
There are several training and development options to consider:
On-the-Job Training – this is when team members shadow more experienced
team members to learn a new skill. This type of training is easy and cost-effective to
set up.
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Instructor-Led Training – this is similar to a "class," where an experienced consultant,
expert, or trainer teaches a group.
Online Training and E-Learning – this can be particularly convenient and cost-
effective.
Cross-Training – this teaches team members how to perform the tasks of their
colleagues. Cross-training helps you create a flexible team, and can lead to higher morale
and job satisfaction.
Active Training – Active Training involves games, group learning, and practical
exercises. This type of training is often effective, because it pushes people to get involved
and be engaged.
Mentoring or Coaching – these can be effective for helping your team members
develop professionally and learn new skills.
Make sure that you take into account people's individual learning styles before you commit to
any one training program. Remember, everyone learns differently; your training will be most
effective if you customize it to accommodate everyone's best learning style. A cost benefit
analysis might also be helpful here, especially if the training you're considering is expensive.
Also, help your team members get the most from their training . Encourage them to arrive on
time, take notes, and communicate with their instructor and each other, about what they have
learned. It might also be helpful to perform a type of "after action review " to see how the
training went.
Tip 1: Our article on Engaging People in Learning has additional tips and strategies that you can use to get your team members excited about their training and development.
Tip 2: You can also use a Training Needs Assessment to identify your people's needs. This help you look at training and development from the perspective of your organization's objectives.
Tip 3: Take our How Well Do You Develop Your People? self-test to boost your overall people development skills.
Key Points Most managers understand that they need to train and develop their people to help them excel. However, it's hard to know where to begin, and sometimes it's even harder to know who needs what training.
Use this process to understand the training and development needs of your team:
1. Review people's job descriptions.
2. Meet with team members.
3. Observe team members at work. 4. Gather additional data.
5. Analyze and prepare data. 6. Determine action steps.
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With this tailored approach, people will feel more empowered, and they'll be able to link what
they learn to their own personal objectives.
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet
provided in the next page:
4. What are the six steps to understand the training and development needs of your team
5. Write the questions to get a better understanding of your people's training needs
6. List training and development options
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
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1. The Ways Leaders Can Support Team Success
Since leaders lead others, usually in groups or teams, any conversation about effective leadership cannot go too far before beginning to discuss how leaders help their teams.
People have spent their lives studying the dynamics of team interactions, how teams form and develop, and the skills needed for team members to be successful. When thought about from this perspective, it is hard to fathom how leaders can ever master these complexities.
On the other hand, people have been working in groups for a very long time, and so while complex, there are things people to do work together better, and so there are things that we as leaders can do to support those efforts.
Since this is such a critical piece of the leader’s list of activities, you will take a dual path approach to these suggestions. In fact, rather than six ways a leader can support team success, it is actually a dozen. For each area, suggest what the leader can do personally and in relationship to those they lead. While you can make some progress by doing the second action in each pair, they will be far more effective done in tandem, as your personal actions and modeling will be at least as powerful as the second half.
So call it six ways, or call it twelve ways . . . either way, let’s get on with it!
1.1 Expect and encourage teamwork. It is difficult to expect people to come together as effective teams if there isn’t a clear and definitive expectation of the importance of that. It may seem obvious to you, but you probably know what assuming can do… if you want great teams, start by making your expectations clear. Then make sure you are encouraging teamwork through your conversations, feedback, recognition and rewards systems and more. Expectations are great, but your daily actions will show how important teamwork is to you and your organization.
1.2 Be committed to team success and help grow the commitment of others. The best teams are committed to their success and to each other. Are you committed to both of those things? As the leader of a team you are also part of the team, too. Yes your role is different, but are you all in for the team? If you aren’t, how can you expect them to be? While being committed yourself is important, you must recognize the importance of this commitment and engagement and encourage it in others as well. This may require conversations, coaching and even conflict resolution, but doing the things that help teams become more committed to the work and each other will pay huge dividends in results.
1.3 Create a team vision and help people personalize it. A team can be committed and “get along” and do great work, but if they aren’t moving in a direction that is the desired direction for overall organizational success, they are less effective than they could be. Whether you set the goals or involve them in setting them, no team can succeed without them. Goals alone aren’t enough however. We must help people
Information Sheet-3 Identifying team members who require additional support
and taking appropriate action
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connect their personal work to the goals of the team and the vision of the organization. Our role as leaders is to help make that happen.
1.4 Focus on relationships and encourage others to do the same. Often leaders make the mistake that if people get to know each other, they will get along better and most, if not all, team problems will melt like the Wicked Witch of the West. While many consultants make a living based on this basic premise, it is short sighted and incomplete. That said, relationships among team members matter and will aid in team development and success. If you want highly successful teams, be a relationship builder and allow time and space for team members to build relationships while they accomplish tasks.
1.5 Be available to help and let your team grow independent of you. Your team will need you, you are committed and are excited and believe in the goals of the team. You must have time and invest time in your team. And . . . you must leave them alone. Don’t micromanage them. People grow and learn with help, but you can’t do things for them. Give them space, opportunity and be patient. Finding this balance may be a challenge, but remember that as they learn and grow you are leveraging that learning for the lifetime of the team.
1.6 Be supportive and encourage team members to support each other. Be supportive both of the team as a whole, which we have already talked about in several ways, but also of the individuals on the team. Remember that a team is made up of individuals, and when you support them you are building their confidence and creating positive attitudes. Since you know that confidence and a positive attitude and energy will improve individual (and team) results, it is important that you not only do this, but help people do the same for each other. Creating this upward spiral or support and encouragement will grow your team’s results as fast as almost any other thing, and it starts with you.
Pick something on this list and get started, start with the thing you feel least comfortable with, then make a plan to integrate all of these actions into your ongoing team leadership approach. You will create tremendous team results and learn a lot for yourself too.
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Self-Check -1 Written Test
Direction I: Give short answer to the following questions. Use the Answer sheet
provided in the next page:
1. List the six ways leader can support team success
2. Explain why a leader create a team vision and help people personalize it
3. Explain how to encourage team members
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Answer Sheet-1
Name: _________________________ Date: _______________
Short Answer Questions
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Score = ___________
Rating: ____________
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REFERENCES
1. Ericsson, Goran N., 2001, “Classification of Power Systems Communications
Needs and Requirements: Experiences from Case Studies at Swedish National
Grid,” IEEE Transactions on Power Delivery, Vol. 16, No. 2.
2. Freeman, Roger L., 1989, Telecommunication System Engineering, 2nd Edition.
John Wiley & Sons, Inc., USA.
3. Greeves, Bill, 1994, “SCADA Uses Radio to Bridge the Gap,” Sensor Review, Vol.
14, No. 2.
4. Hawkins, Shane V. 1997,, “High Roads and Low Roads for SCADA,” Satellite
Communications, 21 (12), pp 44-47.
5. Marihart, Donald J.,2001, “Communications Technology Guidelines for
EMS/SCADA Systems,” IEEE Transactions on Power Delivery, Vol. 16, No. 2.
6. McClanahan, Robert H., 2002, “The Benefits of Networked SCADA Systems
Utilizing IPEnabled Networks,” IEEE Paper No. 02, C5.
7. Nordman, Mikal and Matti Lehtonen, 2001, “TETRA Radio In Monitoring and
Control of Secondary Substations,” IEEE Developments in Power System
Protection Conference, Publication No. 479.
8. Samuels, Phil, 1997, “SCADA and VSAT – a Match from Heaven,” Satellite
Communications, 21 (1), pp 24-27.
9. Usta, O., M.A. Redfern, M. Bayark, 1998, “Data Communications for Power System Relying,”
IEEE-0-7803-3879-0, P. 964-968.
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Prepared By
No Name Educational Background
LEVEL Region College Email Phone
Number
1 Mekonnen Tesfaye
Mechanical Engineer B Oromia AT/K/B PTC [email protected] 0911798867
2