SCADA

SCADA systems for power distribution

School Of Engineering Page1

CHAPTER 1

INTRODUCTION



1. INTRODUCTION

1.1 INTRODUCTION

The aim of our project is to design a system to monitor and control the power for

motors and lighting systems using SCADA (Supervisory Control and Data Acquisition)

system. SCADA systems are used to monitor and control a plant or equipment in industries

such as telecommunications, water and waste control, energy, oil and gas refining and

transportation.

The input voltage, input current, frequency, power factor to a particular load are all

directly fed to PIC (Peripheral Interface Controller) microcontroller measured by suitable

step down voltage and current transformers. The PIC is programmed to calculate the above

mentioned parameters. It will be interfaced with a relay to control the load and a GSM

modem . In case of an abnormal trend in any of the parameters the system will atonce notice

the engineer and turns of the load.

The power condition and controlling through the SCADA system is carried out with

the help of LAB VIEW software. LabVIEW (short for Laboratory Virtual Instrument

Engineering Workbench) is a system-design platform and development environment for

a visual programming language from National Instruments. The labview user interface will

have means of monitoring the parameters , setting the threshold values and control the load.

The interface will also be equipped to show a histogram of the various parameters with time.

1.2 EXISTING SYSTEM

Current, Voltage, Frequency, Power factor were measured by means of various analog

devices and manual database system. Its difficult to analyse the trend in these parameters as

it has to be done manually. Remote controlling and coordination of the machines is a tedious

task.

A particular person should be near to the machine in order to monitor the Current,

Voltage, Frequency , Power factor by using different processing elements and analog

elements. The data have to be manually entered in a log book.



1.3 DRAWBACKS

Gives inaccurate production information.

Increase company downtime.

Minimum safety.

Increase the working time of human.

Careless operation may cause fault

Error margin is high.

Trend analysis is difficult

Remote control and coordination is difficult.

Maintaining database is difficult

1.4 PROPOSED SYSTEM

This project is very useful to monitor the voltage, current, frequency and power factor of the

machines . The parameters are monitored by means of a SCADA system . The parameters are

measured by a embedded system which is designed to measure and indicate the parameters.

The load potential and current are fed to the system by means of suitable current transformers

and potential transformers .

The system will also be equipped with a GSM system to alert the engineer in an event

of malfunction . The system will be interfaced with a computer by means of a RS232

protocol . In this project we create the SCADA interface with the help of Lab VIEW. It will

also have the provision to display the histograms of various parameters thus enabling to

easily analyse the trend in variation of the parameters

1.5 ADVANTAGES

Improved accuracy in parameter measurement

Time saving

Safety increased considerably as the worker need not be close to machine

Error margin is min.

Trend analysis is an easy task

Remote control and coordination is possible.

Digital database management is simpler



CHAPTER 2

LITERATURE REVIEW



2. LITERATURE REVIEW

Company Overview

2.1 ABOUT BHEL:

BHEL is an integrated power plant equipment manufacturer and one of the largest

engineering and manufacturing companies in India in terms of turnover. It was established in

1964, ushering in the indigenous Heavy Electrical Equipment industry in India - a dream that

has been more than realized with a well-recognized track record of performance. The

company has been earning profits continuously since 1971-72 and paying dividends since

1976-77.

BHEL is engaged in the design, engineering, manufacture, construction, testing,

commissioning and servicing of a wide range of products and services for the core sectors of

the economy, viz. Power, Transmission, Industry, Transportation (Railway), Renewable

Energy, Oil & Gas and Defence. BHEL have 16 manufacturing divisions, two repair units,

four regional offices, eight service centres and 15 regional centres and currently operate at

more than 150 project sites across India and abroad. BHEL research and development (R&D)

efforts are aimed not only at improving the performance and efficiency of BHEL existing

products, but also at using state-of-the-art technologies and processes to develop new

products.

The high level of quality & reliability of BHEL products is due to adherence to

international standards by acquiring and adapting some of the best technologies from leading

companies in the world including General Electric Company, Alstom SA, Siemens AG and

Mitsubishi Heavy Industries Ltd., together with technologies developed in BHEL own R&D

centres.

Most of BHEL manufacturing units and other entities have been accredited to Quality

Management Systems (ISO 9001:2008), Environmental Management Systems (ISO

14001:2004) and Occupational Health & Safety Management Systems (OHSAS

18001:2007).



BHEL have a share of 57% in Indias total installed generating capacity contributing

69% (approx.) to the total power generated from utility sets (excluding non-conventional

capacity) as of March 31, 2013.

BHEL have been exporting power and industry segment products and services for

over 40 years. BHELs global references are spread across over 75 countries. The cumulative

overseas installed capacity of BHEL manufactured power plants exceeds 9,000 MW across

21 countries including Malaysia, Oman, Iraq, the UAE, Bhutan, Egypt and New Zealand.

BHEL physical exports range from turnkey projects to after sales services.

2.2 BHEL TRICHY:

BHELs Tiruchirapalli complex is Indias largest manufacturer of boilers and

auxiliaries providing total boiler land solution for Utility, Industrial, Captive power and Heat

Recovery applications.

The plant achieved its full annual capacity to design manufacture and supply high

pressure boiler equipment up to 4000MW in 1984 with boiler unit ratings up to 500MW.

BHEL, trichy has over the years seen formidable growth in capacity, capability,

turnover and profitability. Product diversification has resulted in the development of new

products enabling BHEL to absorb morden technologies. Such innovations result in

continuous updating of manufacturing facilities to serve the customers in a more

comprehensive way and for improving quality and productivity.

THE BHEL TIRUCHIRAPALLI COMPLEX COMPRISES FIVE UNITS:

High Pressure Boiler plant (HPBP) Trichy

Seamless steel Plant (SSTP) Trichy

Boiler Auxiliaries Plant (BAP) Ranipet

Piping Center (PC) Chennai

Industrial Valves Plant (IVP) Govindwal.



POWER CAPABILITY:

BHEL has supplied boilers and auxiliaries accounting for nearly 70% of the

installed thermal power generation capacity in India. BHEL has successfully executed boiler

projects in Malaysia and the Middle East and continues to secure repeat orders from overseas

customers for servicing and renovation of boilers.

For power generation application, BHEL Designs, Engineers, Manufactures,

Suppliers, Erects and Commissions boilers of any rating upward of 30 MW.

For higher capacities, BHEL also offers customers the option of once through type

steam generators in addition to conventional natural and controlled circulation types.BHEL

utility boilers account for over 65% of the total installed thermal power generation capacity in

India.

BHEL supplies steam generators rating up to 450 ton/hr, for industrial application to

suit the requirements of industries viz. Fertilizers, Petro chemical, refinery, steel, paper and

other process industries.

Boilers of various types are supplied including vertical package (Oil/Gas Fixed),

Vertical units (Oil/Gas/Coal fixed), fluidized bed combustion (Coal and other solid fuels),

Chemicals recovery, Waste of heat recovery , Stoker fixed chemical recovery boilers of

capacity ranging from 100 to 1350 ton/day of dry solids are manufactured for the paper and

pulp industry.



2.3ABOUT BUILDING 50:

TUBULAR PRODUCTION SHOP:

Building 50 is to produce the tubular products. Ti consists of machines like

Bending machine.

Tig and mig welding machine.

Induction pressure machine.

Resistance and flash bed welding machine.

Panel processing machine.

Stud welding machine.

Continuous discharge furnace.

BAY 1- Heat recovery stream generator module & water wall panel.

BAY 2- Water wall panel.

BAY 3- Re-heater coils & super heater coils.

BAY 4- Low temperature super heater coils.

BAY 5- Flat thin welding panels.

BAY 6- Heat temperature shop.

BAY 7- Low temperature super heater coils.

BAY 8- Economizer coils.

BAY 9- Radiant roof panel.

BAY A- tube preparation.

BAY B- Shipping.

TUBULAR PRODUCTION:

In tubular production building tubes are brought as raw materials then, they are made

to prepare. The tubes are first subjected to end cutting process. Here the tube ends are cut to

correct size & then send to end preparation process.

In end preparation the cut end of the tubes are chambered deals with tapering the tube end

form. This chambered ends are bored slightly to make it easy to be welded with another tube.



Other than these three basic process like cleaning for removing rust & painting tubes for

further protection are done to make the tubes ready to build boiler protection.

MAJOR ACTIVITIES:

Erection & commissioning of all new machines in short period.

In house designing fabrication & erection of tubes & coil handling system.

System improvement to enhance productivity.

LPG convertion of producer gas furnace.

Indigenous development of machine.



CHAPTER 3

PROJECT DETAILS



3.PROJECT DETAILS

3.1 SYSTEM SPECIFICATION

3.1.1 HARDWARE REQUIREMENTS:

Power supply:

230-12v transformer

bridge rectifier

capacitor

7805 IC

Micro controller(PIC16F877A)

Voltage measurement:

Voltage transformer

Bridge rectifier

Capacitor

Resistor

Current measurement:

Current transformer

Bridge rectifier

capacitor

Resistor



Powerfactor measurement:

Voltage transformer

Current transformer

Resistor

LM358

Switch

Relay

Diode

Transistor

16X2 Lcd display

LED

3.1.2 SOFTWARE REQUIREMENTS:

LABVIEW [ National Instruments]

MPLab

Proteus [ISIS]

PIC programmer



3.2 BLOCK DIAGRAM

Fig 1 : Block Diagram

BLOCK DIAGRAM DESCRIPTION

Potential Transformer

Potential transformers are used in usually in industrial and power plant settings to

reduce the AC voltage of a power line to a lower value (typically 120 or 70 volts full scale)

for instrumentation purposes. They are low power, have accurate voltage ratios and good

galvanic isolation to isolate the instrumentation (and the operators) from dangerous voltages

and power. In this system the input of the PIC microcontroller can withstand only upto 5 V.

The load voltage is stepped down by means of a PT and is fed to a precision rectifier and to

the ZCD circuits for the measurement of Voltage and Power Factor and Frequency.



Current Transformer

Current transformers are used to scale a large AC current which can be 10s of thousands of

amps or more to be measured to a lower value, typically 1 or 5 Amperes that does not require

heavy wires to carry the full current flow to be measured into the instrumentation. They are

low power, do not disturb the current to be measured, have accurate current ratios, and like

potential transformers, good galvanic isolation to isolate the instrumentation (and the

operators) from dangerous voltages and power. The current transformer steps down the

current to suitable values to be fed to the PIC. The output of the CT is fed across the Shunt

resistor and is also fed to the ZCD for measuring the load Current and Power factor.

Precision Rectifier

The precision rectifier, also known as a super diode, is a configuration obtained with

an operational amplifier in order to have a circuit behave like an ideal diode and rectifier. It is

useful for high-precision signal processing. Rectifier circuits are used in the design of power

supply circuits. In such applications, the voltage being rectified are usually much greater

than the diode voltage drop, rendering the exact value of the diode drop unimportant to the

proper operation of the rectifier. The stepped down load output from the Potential

Transformer is fed to the Precision rectifier where its rectified to +6V . This is further fed

across a variable voltage divider circuit from which it is fed to the PIC. Voltage is calculated

taking the ratios of the divider and PT into consideration . The voltage divider circuit is

employed as the maximum input that can be given to a PIC input is +5V .

Shunt Resistor

A shunt resistor is a precision device used to measure current in an electrical circuit. Also

known as a current shunt or an ammeter shunt, it works by measuring the voltage drop across

a known resistance. Ohms law states that V = I x R, or solving for I, I = V / R, where I is

current, V is voltage, and R is resistance. If the resistance is known and the voltage drop is

measured, then the current can be determined.

Shunt resistors are used to measure currents that would potentially damage a device.

This could be a result of the magnitude of the current passing through the circuit or the



possibility of current spikes. They usually have a small, well-defined resistance so as not to

affect the current they are measuring. A shunt resistor typically looks different from a normal

resistor, having two large terminals with one or more strips of metal connecting them. The

resistance of a metal is inversely proportional to its cross-sectional area, so the more strips a

shunt resistor has, the lower its resistance.

ZCD

A comparator is a circuit that accepts two voltages, V1 and V2 and outputs zero volts

if V1>V2 or outputs a positive voltage level if V2>V1. Comparators can be built from

operational amplifiers. They are basic operational amplifier circuits that compare two

voltages simultaneously and switch the output according to the comparison. Zero crossing

detection circuit is a comparator example. A zero crossing detector literally detects the

transition of a signal waveform from positive and negative, ideally providing a narrow pulse

that coincides exactly with the zero voltage condition.

Here two ZCD are used one for current and voltage . In order to measure the power

factor the time gap between two positive edges of the comparator o/ps are measured and the

power factor is calculated from it . The frequency is also measured from any one of the

comparator circuit

Logic Circuit

Logic circuit is an electric circuit whose output depends upon the input in a way that can be

expressed as a function in symbolic logic; it has one or more binary inputs (capable of

assuming either of two states, e.g., "on" or "off") and a single binary output. Logic circuits

that perform particular functions are called gates. Basic logic circuits include the AND gate,

the OR gate, and the NOT gate, which perform the logical functions AND, OR, and NOT.

Logic circuits can be built from any binary electric or electronic devices,

including switches, relays, electron tubes, solid-state diodes, and transistors; the choice

depends upon the application and design requirements. Modern technology has produced

integrated logic circuits, modules that perform complex logical functions. A major use of

logic circuits is in electronic digital computers.



LCD

LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of

applications. In this project we use a 16*2 LCD display. A 16x2 LCD display is very basic

module and is very commonly used in various devices and circuits. These modules are

preferred over seven segments and other multi segment LEDs. The reasons being: LCDs are

economical; easily programmable; have no limitation of displaying special & even custom

characters (unlike in seven segments), animations and so on.

A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In

this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers,

namely, Command and Data.

The command register stores the command instructions given to the LCD. A

command is an instruction given to LCD to do a predefined task like initializing it, clearing

its screen, setting the cursor position, controlling display etc. The data register stores the data

to be displayed on the LCD.

Here the LCD is used to display the various parameters that is Voltage , Current ,

Power Factor and Frequency.

PIC MICROCONTROLLER

PIC is a family of modified Harvard architecture microcontrollers made by Microchip

Technology, derived from the PIC1650 originally developed by General Instrument's

Microelectronics Division. The name PIC initially referred to Peripheral Interface

Controller The first parts of the family were available in 1976; by 2013 the company had

shipped more than twelve billion individual parts, used in a wide variety of embedded

systems.

Early models of PIC had read-only memory (ROM) or field-programmable EPROM

for program storage, some with provision for erasing memory. All current models use Flash

memory for program storage, and newer models allow the PIC to reprogram itself. Program

memory and data memory are separated. Data memory is 8-bit, 16-bit and in latest models,

32-bit wide. Program instructions vary in bit-count by family of PIC, and may be 12, 14, 16,

or 24 bits long. The instruction set also varies by model, with more powerful chips adding

instructions for digital signal processing functions.



The various inputs for the parameter measurement are fed to the PIC. PIC calculates

the parameters and drives the relay and alarm circuit . The PIC is interfaced to a computer

using RS232 protocol

DRIVER CIRCUIT

In electronics,a driver is an electrical circuit or other electronic component used to control

another circuit or component, such as a high-power transistor, liquid crystal display (LCD),

and numerous others.

They are usually used to regulate current flowing through a circuit or is used to

control the other factors such as other components, some devices in the circuit. The term is

often used, for example, for a specialized integrated circuit that controls high-

power switches in switched-mode power converters. An amplifier can also be considered a

driver for loudspeakers, or a constant voltage circuit that keeps an attached component

operating within a broad range of input voltages.

Transistor triggered driver circuits are used in order to activate the Relay and Alarm .

A high output from the PIC will enable the circuits to activate or drive the Relay/Alarm

system

RS 232

The RS-232 interface is the Electronic Industries Association (EIA) standard for the

interchange of serial binary data between two devices. It was initially developed by the EIA

to standardize the connection of computers with telephone line modems. The standard allows

as many as 20 signals to be defined, but gives complete freedom to the user. Three wires are

sufficient: send data, receive data, and signal ground. The remaining lines can be hardwired

on or off permanently. The signal transmission is bipolar, requiring two voltages, from 5 to

25 volts, of opposite polarity.

An RS-232 serial port was once a standard feature of a personal computer, used for

connections to modems, printers, data storage, uninterruptible power supplies, and other

peripheral devices. However, RS-232 is hampered by low transmission speed, large voltage



swing, and large standard connectors. In modern personal computers, USB has displaced RS-

232 from most of its peripheral interface roles.

RELAY

A relay is an electrically operated switch. Many relays use an electromagnet to mechanically

operate a switch, but other operating principles are also used, such as solid-state relays.

Relays are used where it is necessary to control a circuit by a low-power signal (with

complete electrical isolation between control and controlled circuits), or where several

circuits must be controlled by one signal. The first relays were used in long

distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit

and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges

and early computers to perform logical operations.

A type of relay that can handle the high power required to directly control an electric

motor or other loads is called a contactor. Solid-state relays control power circuits with

no moving parts, instead using a semiconductor device to perform switching. Relays with

calibrated operating characteristics and sometimes multiple operating coils are used to protect

electrical circuits from overload or faults; in modern electric power systems these functions

are performed by digital instruments still called "protective relays".

In this system the relay isolates the load from the supply in an event of abnormal

parameter readings or if the maintenance switch is switched.

ALARM

Alarm circuit is used to notify the user of large variations in circuit parameters. Transistor

triggered buzzer circuit is employed. On event of a variation in parameter an ouput from a pin

of pic will trigger the transistor causing the buzzer to a



3.3 CIRCUIT DIAGRAM AND EXPLANATION

3.3.1 Complete Circuit

Fig 2 : Complete Circuit Diagram



3.3.2 Voltage Measurement Circuit

Fig 3 : Voltage Measurement Circuit

The circuit is designed to monitor the supply voltage. Supply voltage that has to be given is

stepped down by the potential transformer which is rectified by the precision rectifier. The

precision rectifier is a configuration obtained with an operational amplifier in order to have a

circuit behaving like an ideal diode or rectifier.

The full wave rectifier is the combination of half wave rectifier and a summing

amplifier. When the input voltage is negative, the diode is reverse biased , thus it works like

an open circuit. There will be no current flow through the load and hence the output voltage

will be zero. When the input is positive , it is amplified ny the operational amplifier which

makes the diode forward biased. Current will flow in the load and because of the feedback

circuit the output voltage is equal to the input.

When the input voltage is greater than zero, the diode D2 is ON and D1 is OFF, hence

the output is zero. When the input voltage is less than zero, D2 is OFF and D1 is ON, and the

output will be similar to the input but with an amplification of R2/R1. The full wave

rectifier working depends on the fact that both the half wave rectifier and the summing

amplifier are precision circuits. It operates by producing an inverted half wave rectified signal

and then adding the signal at double amplitude to the original signal in the summing

amplifier. The result is a reversal of the selected polarity of the input signal.



Then the output of the rectifier is adjusted to 0-5v with the help of a variable resistor VR1.

The input is given to the ADC module where it is converted on the basis of the

calculated ratios of transformer and rectifier circuit.

3.3.3 Current Measurement Circuit

Fig 4 : Current Measurement Circuit

This circuit is designed to monitor the supply current. The supply current that has to

be monitored is stepped down by the current transformer. The step down current is converted

to the required value by the help of a shunt resistor. Then the converted voltage is rectified by

the precision rectifier. The precision rectifier is a configuration obtained with a operational

amplifier in order to have a circuit behaving like an ideal diode or rectifier.

The full wave rectifier combination of half wave precision rectifier and summing

amplifier. When the input voltage is negative, there is a negative voltage on the diode 2,

hence it works as an open circuit. There will be no current through the load and therefore the

output voltage is zero. When the input is positive it is amplified the operational amplifier and

it turns the diode ON. There is current in the load and because of the feedback circuit , the

output voltage will be equal to input voltage.

In this case , when the input is greater than zero D2 is ON and D1 is OFF, hence the

output will be zero. When the input is less than zero , D2 iss OFF and D1 is ON and output is



like the input but with an amplification of R2/R1. The full wave rectifier working depends

on the fact that both the half wave rectifier and the summing amplifier are precision circuits.

It operates by producing an inverted half wave rectified signal and adding that signal at

double amplitude to the original signal in the summing amplifier. The result is reversal of the

selected polarity of the input signal.

The potential across the Shunt resistor is fed to the PIC which is measured and

current is calculated from the potential.

3.3.4 Power factor and Frequency Measurement Circuit

Fig 5 : Power factor and Frequency Measurement Circuit

This circuit is designed to find the power factor in the power line. The power line voltage and

current is monitored through the potential and current transformers respectively.

The potential transformer is used to step down the main supply voltage to the low voltage

level. The voltage level is stepped down from 230 voltage ac to 6v ac. A zero crossing

detector is used as analog circuit to achieve the converting process of the current and voltage

signals. the outputs of the current and voltage transformers are connected to numbered pins 2

and 6 of



LM358, respectively. When AC signal is applied to LM358, the output of LM358 is 1 as

logically (5 Volt) while signal is crossing from the zero point. If the AC signal is different

from zero, the output is 0 (0 Volt). The input and output signals of LM358 are given in Fig.

Fig 6 : LM358 Input/Output waveform

There are two inputs and outputs of LM358. One of them is used for the current signal. The

other one is used for the voltage signal. The current and voltage signals are taken the same

phase for measuring the power factor.The

current and voltage signals taken from the load are adapted into LM358 using current and

voltage transformers The logical voltage and current signals are inserted pins RA2and RA3

of PIC16F877. TIMER0 of PIC16F877 is worked when the voltage signal is passing from

zero point.TIMER0 is stopped when current signal is passing from zero point. TIMER0 is a

special storage at the 01h address of RAM. It is possible to start counting from 00h address or

any wanted number and to make zero of its content. The logic and algorithm of the

measurement is depicted in the below figure.



Fig 7 : Powerfactor program flow chart



3.3.5 Frequency Measurement

TIMER0 is stopped when current signal is passing from zero point. TIMER0 is a special

storage at the 01h address of RAM. It is possible to start counting from 00h address or any

wanted number and to make zero of its content. The counter is verified at the end of 60

seconds and the frequency is identified on the basis of counter value. An output from one of

the LM358 ZCD is fed to RC0 from which the frequency is measured.

3.3.6 GSM interface Circuit

Fig 8 : GSM interface circuit

SIM300 GSM Modem is able to take any GSM network operator SIM card and behave

just like a mobile phone with its own unique phone number. The RS232 interface lets

modem to communicate with RS232 port of PC or compatible embedded system

circuitry. Implementation of SMS controlled devices, Auto reply; remote control is

possible via SIM300. The modem can be directly interfaced with microcontroller. It can

be used to send, receive and process SMS/ call. The MAX232 is an IC, first created in

1987 by Maxim Integrated Products, that converts signals from an RS-232 serial port to

signals suitable for use in TTL compatible digital logic circuits. The MAX232 is a dual

driver/receiver and typically converts the RX, TX, CTS and RTS signals. The

MAX232(A) has two receivers (converts from RS-232 to TTL voltage levels), and two

drivers (converts from TTL logic to RS-232 voltage levels). This means only two of the

RS-232 signals can be converted in each direction. Typically, a pair of a driver/receiver of

the MAX232 is used for TX and RX signals, and the second one for CTS and RTS

signals.



When any one of the parameter exhibits any abnormal variation the relay will isolate

the load and sends a message One of the parameter has exceeded the limit to the

corresponding engineer thereby helping the engineer know the situation.

3.3.7 PC interface Circuit

Fig 9 : PC interface circuit

The MAX232 is an IC, first created in 1987 by Maxim Integrated Products, that converts

signals from an RS-232 serial port to signals suitable for use in TTL compatible digital

logic circuits. The MAX232 is a dual driver/receiver and typically converts the RX, TX,

CTS and RTS signals. The MAX232(A) has two receivers (converts from RS-232 to TTL

voltage levels), and two drivers (converts from TTL logic to RS-232 voltage levels). This

means only two of the RS-232 signals can be converted in each direction. Typically, a

pair of a driver/receiver of the MAX232 is used for TX and RX signals, and the second

one for CTS and RTS signals.

Data is transferred across PC and embedded system via RS232 protocol . The system

is controlled and communicated by the System control user interface program designed in

LABVIEW. Utilising the user interface we can use the computer to turn on and off the

system , monitor the parameters as well present the engineer with the histograms or

variation pattern of various parameters.



3.3.8 Interfacing GSM and PC to the same PIC

Fig 10 : GSM PIC simultaneous interfacing

Since only one USART pins are available in the PIC16f877a its essential that we

employ some mechanism to connect both GSM modem and PC to the same PIC. A relay

mechanism has been employed in this project. The system remains connected to the computer

normally. On event of any abnormal parameter variation the GSM relay actuates and GSM

comes into connection with the USART pin isolating the system for the moment and

notifying the engineer. Thus we can connect both computer and GSM modem without

employing multiple Microcontrollers



3.3.9 Alarm Circuit

Fig 11 : Alarm circuit

This circuit is used to control the buzzer/speaker circuit. When any one of the parameters

exceeds normal values alarm is triggered. When a high pulse is given to the base of the

transistor, it starts conducting and completes the speaker circuit thereby causing the alarm to

sound .



3.3.10 Relay Circuit

Fig 12 : Relay circuit

A relay is an electromagnetic switch which is used to switch High Voltage/Current using

Low power circuits. Relay isolates low power circuits from high power circuits. It is activated

by energizing a coil wounded on a soft iron core. A relay should not be directly connected to

a microcontroller, it needs a driving circuit. A relay can be easily interfaced with

microcontroller using a transistor as shown below. Transistor is wired as a switch which

carries the current required for operation of the relay. When the pin of the PIC

microcontroller goes high, the transistor turns On and current flows through the relay. The

diode D1 is used to protect transistor and the microcontroller from Back EMF generated in

the relays coil. Normally 1N4148 is preferred as it is a fast switching diode having a peak

forward current of 450mA. This diode is also known as freewheeling diode.

The Relay Circuit is used to isolate the load from the supply that is turn of the load in

an event of parameter variation . When a parameter exceeds the limit the relay is actuated

thereby removing the load or turning it off.



3.3.11 Complete Working

This system is used to control the AC load using a PC and monitor its parameters .

The voltage , current , power factor and frequency parameters are continuously monitored .

The parameters are monitored in the LCD display as well as in the computer . From the

computer we are able to control the load and also view the histogram. The relay circuit is

activated when any one of the parameters is exceeded and also the alarm is also triggered . If

the maintenance switch is turned on the relay keeps the load isolated for maintenance

purpose.

3.4 USER INTERFACE

Fig 13 : User Interface



The User Interface application facilitates the communication between the user and embedded

system through Computer. The application is developed by means of LAB VIEW software by

National Instruments .

LabVIEW (short for Laboratory Virtual Instrument Engineering Workbench) is a system-

design platform and development environment for a visual programming

language from National Instruments.

The graphical language is named "G" (not to be confused with G-code). Originally

released for the Apple Macintosh in 1986, LabVIEW is commonly used for data

cquisition, instrument control, and industrial automation on a variety of platforms

including Microsoft Windows, various versions of UNIX, Linux, and Mac OS X.

LabVIEW ties the creation of user interfaces (called front panels) into the

development cycle. LabVIEW programs/subroutines are called virtual instruments (VIs). A

key feature of LabVIEW is the extensive support for interfacing to devices such as

instruments, cameras, and other devices. Users typically interface to hardware by either

writing direct bus commands (USB, GPIB, Serial...) or using high-level, device-specific,

drivers that provide native LabVIEW function nodes for controlling the device. National

Instruments makes thousands of device drivers available for download on the Instrument

Driver Network (IDNet).

The UI developed here has the means of cotrolling (ON/OFF) the load using the

computer. The threshold values of the various parameters for a particular load can be set from

the Parameter Control section . The Indicator module displays the real time values of the

four parameters. In case of any abnormal variation in parameters the blinkers at the right end

corner will indicate which parameter has exceeded the limits. The real time parameters are

stored in a database and can be viewed in a graphical manner on clicking the HISTOGRAM

button .The UI depicted here is the one designed for the model that is to control one AC load.

It can be modified to include all the equipments in the Bay.

3.4.1 HISTOGRAM

Histogram provides the graphical representation of the various parameters against

time. The real time parameters will be stored in computer database. On clicking the

Histogram Button in the UI a graph plotting all the parameters against time will be shown.



Histogram is very useful to analyse the trend in variation of the parameters. Histograms are

helpful in comparing the performance of load with standard values. A typical Histogram used

in the system is shown below

Fig 14 : Histogram

The real time values of the various parameters can be stored in a database and produced later

for analysis purpose . A window showing the real time values of the different parameters of

all the equipments in the bay is shown. The real time parameters of all the equipments in Bay

50 has been depicted in the below figure .

Fig 15 : Real time data



Advantages of using Histograms :

Real time comparison of parameter variation is possible

Can easily identify the trend in parameter variation

Time based load parameter variation can be viewed



CHAPTER 4

PROJECT OUTCOME



4. PROJECT OUTCOME

An embedded system capable of monitoring the parameters of the equipments in a factory

and protecting the equipment has been developed . The system is capable of being controlled

remotely from a computer by means of UI application developed in LAB VIEW . The

connection between the measurement system and computer has been employed by means of

RS232 protocol .GSM system employed will help the engineer notify any error at the instant .

An effective system capable of monitoring controlling the equipments in factories and

notifying the engineer has been developed

The proposed system has the following advantages

Accurate parameter measurement is possible

As all the measurements are done in real time , its time and cost effective.

The load parameters can be measured remotely , that is the worker need not be close

to the system for measurement , hence safety factor is considerably increased

As human error probability is completely removed the margin of error in parameter

measurement is reduced

Since histograms are available time based parameter variation analysis of AC load

is possible

As Relay mechanism has been employed it protects the equipment in an event of

abnormal parameter variation.

Since digital database has been employed its management is much simpler and can

be used conveniently for analysis.

Use of GSM technology helps in notifying the engineer any abnormality in the

factory.

Following are the limitations of the project

Wired communication has been employed between remote computer and system , any

mechanical damage to the wire will shut down the system.

In order to facilitate wireless communication all the parameters for all the equipment

have to be transferred after encryption making it difficult and costly to implement

Reliability of system is moderate due to the failure chances of the microcontroller



CHAPTER 5

CONCLUSION



5.1 CONCLUSION

The proposed system will help in improving the overall efficiency of the factory.

Though the initial cost in setting up such a system is high the payback period is quite low and

helps in improving the output of factory. Timely maintenance and protection of system can

be ensured by employing this system. We have proposed a brief or abstract system here.

E a c h a n d e v e r y p r o j e c t i s n e v e r c o m p l e t e a s n e w t h i n g s a r e l e a r

n e d f u r t h e r modifications can be done. The system can be further developed to

accommodate more parameters and add new facilities.

5.2 FUTURE SCOPE

The development of this project surely prompts many new areas of investigation. This

project has wide scope to implement it in any factory bays with multiple equipments

operating simultaneously. This project covers all functionalities related load parameter

analysis and control. Hence it can be implemented any-where else after minute organization

level customization

Moreover some parts of the project have remained uncompleted due to some reasons.

First of all limitations of our project, which has been discussed in previous topic make place

for future enhancements.

The project can be developed to measure more parameters such as harmonics and so .

In the proposed system the data communication between system and computer is facilitated

by RS232 protocol. It can be replaced by wireless communication such as IR or any other

encrypted protocol. In future the system may be equipped with optoelectronic isolators

thereby increasing the factor of safety and accuracy more.



CHAPTER 6

BIBILOGRAPHY



6. BIBILOGRAPHY

Industrial automation : Dvid W. Pessen

Supervisory control and data acquisition Gaushell, D.J. ; Westin Engineering, Inc.,

San Jose, CA, USA ; Darlington, H.T. Published in: Proceedings of the IEEE

(Volume:75 , Issue: 12 )

Embedded-labs.com

8051projects.neT

Circulatory.com

Pictutorials.com



CHAPTER 7

APPENDIX



7.1 APPLICATIONS USED

7.1.1 MPLAB

MPLAB IDE is an integrated development environment that provides development

engineers with the flexibility to develop and debug firmware for various Microchip devices.

MPLAB IDE is a windows-based integrated development for the microchip

technology incorporated PIC microcontroller (MCU) and dsPIC digital signal controller

(DSC) families. In the MPLAB IDE, you can:

Create source code using the built-in editor.

Assemble, compile and link source code using various language tools. An assembler,

linker and librarian come with MPLAB IDE. C compilers are available from

microchip and other third party vendors.

Debug the executable logic by watching program flow with a simulator, such as

MPLAB SIM, or in real time with an emulator, such as MPLAB ICE. Third party

emulators that work with MPLAB IDE are also available.

Make timing measurements.

View variables in watch windows.

Find quick answers to questions from the MPLAB IDE on-line help.

7.1.2 PROTEUS

Proteus 7.0 is a Virtual System Modelling (VSM) that combines circuit simulation, animated

components and microprocessor models to co-simulate the complete microcontroller based

designs. This is the perfect tool for engineers to test their microcontroller designs before

constructing a physical prototype in real time. This program allows users to interact with the

design using on-screen indicators and/or LED and LCD displays and, if attached to the PC,

switches and buttons. One of the main components of Proteus 7.0 is the Circuit Simulation --

a product that uses a SPICE3f5 analogue simulator kernel combined with an event-driven

digital simulator that allow users to utilize any SPICE model by any manufacturer.



Proteus VSM comes with extensive debugging features, including breakpoints, single

stepping and variable display for a neat design prior to hardware prototyping.

In summary, Proteus 7.0 is the program to use when you want to simulate the interaction

between software running on a microcontroller and any analog or digital electronic device

connected to it.

7.1.3 LABVIEW

LabVIEW (short for Laboratory Virtual Instrument Engineering Workbench) is a system-

design platform and development environment for a visual programming

language from National Instruments.

The graphical language is named "G" (not to be confused with G-code). Originally released

for the Apple Macintosh in 1986, LabVIEW is commonly used for data

acquisition, instrument control, and industrial automation on a variety of platforms

including Microsoft Windows, various versions of UNIX, Linux, and Mac OS X. The latest

version of LabVIEW is LabVIEW 2014, released in August 2014.

The programming language used in LabVIEW, also referred to as G, is a dataflow

programming language. Execution is determined by the structure of a graphical block

diagram (the LabVIEW-source code) on which the programmer connects different function-

nodes by drawing wires. These wires propagate variables and any node can execute as soon

as all its input data become available. Since this might be the case for multiple nodes

simultaneously, G is inherently capable of parallel execution. Multi-processing and multi-

threading hardware is automatically exploited by the built-in scheduler,

which multiplexes multiple OS threads over the nodes ready for execution.

LabVIEW ties the creation of user interfaces (called front panels) into the

development cycle. LabVIEW programs/subroutines are called virtual instruments (VIs).

Each VI has three components: a block diagram, a front panel and a connector panel. The last

is used to represent the VI in the block diagrams of other, calling VIs. The front panel is built

using controls and indicators. Controls are inputs they allow a user to supply information to

the VI. Indicators are outputs they indicate, or display, the results based on the inputs given

to the VI. The back panel, which is a block diagram, contains the graphical source code. All

of the objects placed on the front panel will appear on the back panel as terminals. The back



panel also contains structures and functions which perform operations on controls and supply

data to indicators. The structures and functions are found on the Functions palette and can be

placed on the back panel. Collectively controls, indicators, structures and functions will be

referred to as nodes. Nodes are connected to one another using wires e.g. two controls and

an indicator can be wired to the addition function so that the indicator displays the sum of the

two controls. Thus a virtual instrument can either be run as a program, with the front panel

serving as a user interface, or, when dropped as a node onto the block diagram, the front

panel defines the inputs and outputs for the given node through the connector pane. This

implies each VI can be easily tested before being embedded as a subroutine into a larger

program.

The graphical approach also allows non-programmers to build programs by dragging and

dropping virtual representations of lab equipment with which they are already familiar. The

LabVIEW programming environment, with the included examples and documentation, makes

it simple to create small applications. This is a benefit on one side, but there is also a certain

danger of underestimating the expertise needed for high-quality G programming. For

complex algorithms or large-scale code, it is important that the programmer possess an

extensive knowledge of the special LabVIEW syntax and the topology of its memory

management. The most advanced LabVIEW development systems offer the possibility of

building stand-alone applications. Furthermore, it is possible to create distributed

applications, which communicate by a client/server scheme, and are therefore easier to

implement due to the inherently parallel nature of G.

Benifits

A key feature of LabVIEW is the extensive support for interfacing to devices such as

instruments, cameras, and other devices. Users typically interface to hardware by either

writing direct bus commands (USB, GPIB, Serial...) or using high-level, device-specific,

drivers that provide native LabVIEW function nodes for controlling the device. National

Instruments makes thousands of device drivers available for download on the Instrument

Driver Network (IDNet).

Code compilation

In terms of performance, LabVIEW includes a compiler that produces native code for the

CPU platform. The graphical code is translated into executable machine code by interpreting

the syntax and by compilation. The LabVIEW syntax is strictly enforced during the editing



process and compiled into the executable machine code when requested to run or upon

saving. In the latter case, the executable and the source code are merged into a single file. The

executable runs with the help of the LabVIEW run-time engine, which contains some

precompiled code to perform common tasks that are defined by the G language. The run-time

engine reduces compile time and also provides a consistent interface to various operating

systems, graphic systems, hardware components, etc. The run-time environment makes the

code portable across platforms. Generally, LabVIEW code can be slower than equivalent

compiled C code, although the differences often lie more with program optimization than

inherent execution speed.

Large libraries

Many libraries with a large number of functions for data acquisition, signal generation,

mathematics, statistics, signal conditioning, analysis, etc., along with numerous graphical

interface elements are provided in several LabVIEW package options. The number of

advanced mathematic blocks for functions such as integration, filters, and other specialized

capabilities usually associated with data capture from hardware sensors is immense. In

addition, LabVIEW includes a text-based programming component called MathScript with

additional functionality for signal processing, analysis and mathematics. MathScript can be

integrated with graphical programming using "script nodes" and uses a syntax that is

generally compatible with MATLAB

Code re-use

The fully modular character of LabVIEW code allows code reuse without modifications: as

long as the data types of input and output are consistent, two subVIs are interchangeable.

The LabVIEW Professional Development System allows creating stand-alone executables

and the resultant executable can be distributed an unlimited number of times. The run-time

engine and its libraries can be provided freely along with the executable.

A benefit of the LabVIEW environment is the platform independent nature of the G code,

which is (with the exception of a few platform-specific functions) portable between the

different LabVIEW systems for different operating systems (Windows, Mac OS X and

Linux). National Instruments is increasingly focusing on the capability of deploying

LabVIEW code onto an increasing number of targets including devices like Phar

Lap or VxWorks OS based LabVIEW Real-Time controllers, FPGAs, PocketPCs,

PDAs, Wireless sensor network nodes, and even Lego Mindstorms NXT.



Parallel programming

LabVIEW is an inherently concurrent language, so it is very easy to program multiple tasks

that are performed in parallel by means of multithreading. This is, for instance, easily done by

drawing two or more parallel while loops. This is a great benefit for test system automation,

where it is common practice to run processes like test sequencing, data recording, and

hardware interfacing in parallel.

Ecosystem

Due to the longevity and popularity of the LabVIEW language, and the ability for users to

extend the functionality, a large ecosystem of 3rd party add-ons has developed through

contributions from the community. This ecosystem is available on the LabVIEW Tools

Network, which is a marketplace for both free and paid LabVIEW add-ons.

User community

There is a low-cost LabVIEW Student Edition aimed at educational institutions for learning

purposes. There is also an active community of LabVIEW users who communicate through

several e-mail groups and Internet forums.

Licensing

Building a stand-alone application with LabVIEW requires the Application Builder

component which is included with the Professional Development System but requires a

separate purchase if using the Base Package or Full Development System.[1] There is no

LabVIEW 2011 student license for Linux.

Run-time environment

Compiled executables produced by version 6.0 and later of the Application Builder are not

truly standalone in that they also require the LabVIEW run-time engine be installed on any

target computer which runs the application.[2] The use of standard controls requires a run-time

library for any language. All major operating systems supply the required libraries for

common languages such as C. However, the run-time required for LabVIEW is not supplied

with any operating system and has to be specifically installed by the administrator or user.

This can cause problems if an application is distributed to a user who may be prepared to run

the application but does not have the inclination or permission to install additional files on the

host system prior to running the executable.



Race conditions and pseudo parallel execution

The G gives the impression of being a parallel language (cf VHDL) that has modules that run

in parallel, however, it is essentially implemented on a non parallel platform without explicit

race condition control. While this simplifies programming it gives a false impression of

security.

Performance

LabVIEW makes it difficult to get machine or hardware limited performance and tends to

produce applications that are significantly slower than hand coded native languages such as

C. This is especially obvious in complex applications involving several pieces of hardware.

Light weight applications

Very small applications still have to start the runtime environment which is a large and slow

task. This makes writing and running small applications or applications that might run in

parallel on the same platform problematic and tends to restrict LabVIEW to monolithic

applications. Examples of this might be tiny programs to grab a single value from some

hardware that can be used in a scripting language - the overheads of the runtime environment

render this approach impractical with LabVIEW.



7.2 DATA SHEETS

7.2.1 PIC16F877A MICROCONTROLLER

The microcontroller that has been used for this project is from PIC series. PIC

microcontroller is the first RISC based microcontroller fabricated in CMOS (complementary

metal oxide semiconductor) that uses separate bus for instruction and data allowing

simultaneous access of program and data memory. The main advantage of CMOS and RISC

combination is low power consumption resulting in a very small chip size with a small pin

count. The main advantage of cmos is that it has immunity to noise than other fabrication

techniques.

Various microcontrollers offer different kinds of memories. EEPROM, EPROM, FLASH etc.

are some of the memories of which FLASH is the most recently developed. Technology that

is used in PIC16F877A is flash technology, so that data is retained even when the power is

switched off. CORE FEATURES:

High-performance RISC CPU

Only 35 single word instruction to learn

All single instruction except for program branches which are two cycle

Operating speed: DC - 20 MHz clock input

DC 200 ns instruction cycle

Up to 8K x 14 words of flash program memory,

Up to 368 x 8 bytes of data memory (RAM)

Up to 256 x 8 bytes of EEPROM data memory

Pin out compatible to the PIC 16c 73/74/76/77

Interrupt capability (up to 14 internal/external)

Direct, indirect, and relative addressing modes

Watchdog timer (WDT) with its own on-chip RC oscillator for reliable operation

Programmable code-protection

Power saving SLEEP mode

Selectable oscillator options

Low-power, high-speed CMOS EPROM/EEPROM technology

Only single 5V source needed for programming capability



In-circuit debugging via two pins

Processor read/write access to program memory

Wide operating voltage range: 2.5V to 5.5V

High sink/source current: 25mA

Low-power consumption:

< 2mA typical @ 5V, 4 MHz & 20mA typical @ 3V, 32 kHz

PERIPHERAL FEATURES:

Timer0: 8-bit timer/counter with 8-bit prescaler

Timer1: 16-bit timer/counter with prescaler, can be incremented during Sleep

via external crystal/clock

Timer2: 8-bit timer/counter with 8-bit period register, prescaler and post scalar

Two Capture, Compare, PWM modules

- Capture is 16-bit, max. Resolution is 12.5 ns

- Compare is 16-bit, max. Resolution is 200 ns

- PWM max. Resolution is 10-bit

Synchronous Serial Port (SSP) with SPI (Master mode) and I2C

(Master/Slave)

Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI)

with 9-bit address detection

Parallel Slave Port (PSP) 8 bits wide with external RD, WR and CS controls

(40/44-pin only)

Brown-out detection circuitry for Brown-out Reset (BOR)

Analog Features:

- 10-bit, up to 8-channel Analog-to-Digital Converter (A/D)

- Brown-out Reset (BOR)

Analog Comparator module with:

- Two analog comparators

- Programmable on-chip voltage reference



ARCHITECTURE OF PIC 16F877A:

The complete architecture of PIC 16f877A is shown in the figure.

Fig 16 : PIC 16f877a architecture



Fig 17 : PIN DIAGRAM OF PIC 16F877A:



PIN NUMBER DESCRIPTION:

Pin Number Description

1 MCLR/VPP

2 RA0/AN0

3 RA1/AN1

4 RA2/AN2/VREF-/CVREF

5 RA3/AN3/VREF+

6 RA4/T0CKI/C1OUT

7 RA5/AN4/SS/C2OUT

8 RE0/RD/AN5

9 RE1/WR/AN6

10 RE2/CS/AN7

11 VDD

12 VSS

13 OSC1/CLKI

14 OSC2/CLKO

15 RC0/T1OSO/T1CKI

16 RC1/T1OSI/CCP2

17 RC2/CCP1

18 RC3/SCK/SCL

19 RD0/PSP0



20 RD1/PSP1

21 RD2/PSP2

22 RD3/PSP3

23 RC4/SDI/SDA

24 RC5/SDO

25 RC6/TX/CK

26 RC7/RX/DT

27 RD4/PSP4

28 RD5/PSP5

29 RD6/PSP6

30 RD7/PSP7

31 VSS

32 VDD

33 RB0/INT

34 RB1

35 RB2

36 RB3/PGM

37 RB4

38 RB5

39 RB6/PGC

40 RB7/PGD



7.2.2 LM358

Utilizing the circuit designs perfected for recently introduced Quad

Operational Amplifiers, these dual operational amplifiers feature 1) low

power drain, 2) a common mode input voltage range extending to

ground/VEE, 3) single supply or split supply operation and 4) pinouts

compatible with the popular MC1558 dual operational amplifier. The LM158

series is equivalent to onehalf of an LM124.

These amplifiers have several distinct advantages over standard

operational amplifier types in single supply applications. They can operate at

supply voltages as low as 3.0 V or as high as 32 V, with quiescent currents

about onefifth of those associated with the MC1741 (on a per amplifier

basis). The common mode input range includes the negative supply, thereby

eliminating the necessity for external biasing components in many

applications. The output voltage range also includes the negative power

supply voltage.

Short Circuit Protected Outputs

True Differential Input Stage

Single Supply Operation: 3.0 V to 32 V

Low Input Bias Currents

Internally Compensated

Common Mode Range Extends to Negative Supply

Single and Split Supply Operation

Similar Performance to the Popular MC1558

ESD Clamps on the Inputs Increase Ruggedness of the Device without

Affecting Operation



Fig 18 : LM358 pin diagram



Fig 19 : LM358 schematic diagram

The LM258 series is made using two internally compensated, twostage operational

amplifiers. The first

stage of each consists of differential input devices Q20 and Q18 with input buffer transistors

Q21 and Q17 and the differential to single ended converter Q3 and Q4. The first stage

performs not only the first stage gain function but also performs the level shifting and

transconductance reduction functions. By reducing the transconductance, a smaller

compensation capacitor (only 5.0 pF) can be employed, thus saving chip area. The

transconductance reduction is accomplished by splitting the collectors of Q20 and Q18.

Another feature of this input stage is that the input common mode range can include the

negative supply or ground, in single supply operation, without saturating either the input

devices or the differential to singleended converter. The second stage consists of a standard

current source load amplifier stage.

Each amplifier is biased from an internalvoltage regulator which has a low temperature

coefficient thus giving each amplifier good temperature characteristics as well as excellent

power supply rejection.



Fig 20 : LM358 charecteristics



Fig21 : LM 358 package



7.2.3 LCD DISPLAY

2 x 16 LCD DISPLAY:

Liquid crystal displays (LCDs) have materials which combine the properties of both

liquids and crystals. Rather than having a melting point, they have a temperature range within

which the molecules are almost as mobile as they would be in a liquid, but are grouped

together in an ordered form similar to a crystal.

An LCD consists of two glass panels, with the liquid crystal material sand witched in

between them. The inner surface of the glass plates are coated with transparent electrodes

which define the character, symbols or patterns to be displayed polymeric layers are present

in between the electrodes and the liquid crystal, which makes the liquid crystal molecules to

maintain a defined orientation angle. One each polarizes are pasted outside the two glass

panels. These polarizes would rotate the light rats passing through them to a definite angle, in

a particular direction.

When the LCD is in the off state, light rays are rotated by the two polarizes and the

liquid crystal, such that the light rays come out of the LCD without any orientation, and

hence the LCD appears transparent. When sufficient voltage is applied to the electrodes, the

liquid crystal molecules would be aligned in a specific direction. The light passing through

the LCD would be rotated by the polarizes which result in activating/highlighting the desired

characters.

The LCDs are lightweight with only a few millimeters thickness. Since the LCDs

consume less power, they are compatible with low power electronic circuits and can be

powered for long durations. The LCDs dont generate light and so light is needed to read the

display. By using backlighting, reading is possible in the dark. The LCDs have long life and

a wide operating temperature range.

Changing the display size or the layout size is relatively simple which makes the

LCDs more customer friendly. The LCDs used exclusively in watches, calculators and

measuring instruments are the simple seven-segment displays, having a limited amount of

numeric data. The recent advances in technology have resulted in better legibility, more

information displaying capability and a wider temperature range. These have resulted in the

LCDs being extensively used in telecommunications and entertainment electronics. The



LCDs have even started replacing the cathode ray tubes (CRTs) used for the display of text

and graphics, and also in small TV applications.

PIN DIAGRAM OF LCD DISPLAY:

Fig 22 : LCD pin diagram

PIN DESCRIPTION FOR LCD DISPLAY

Pin

No Function Name

1 Ground (0V) Ground

2 Supply voltage; 5V (4.7V 5.3V) Vcc

3 Contrast adjustment; through a variable resistor

VEE

4 Selects command register when low; and data register when high Register Select

5 Low to write to the register; High to read from the register Read/write



6 Sends data to data pins when a high to low pulse is given Enable

7

8-bit data pins

DB0

8 DB1

9 DB2

10 DB3

11 DB4

12 DB5

13 DB6

14 DB7

15 Backlight VCC (5V) Led+

16 Backlight Ground (0V) Led-

LCD DISPLAY WITH PIC:



7.2.4 MAX232

MAX232 is purposed for application in high-performance information processing systems

and control devices of wide application.

Input voltage levels are compatible with standard _MOS levels.

Output voltage levels are compatible with input levels

of K-MOS, N-MOS and TTL integrated circuits.

; 0.1

inputs are protected to 15kV Air ESD.



Fig 23 : Max232 pinout diagram



7.2.4 GSM SIM 300

Product concept

Designed for global market, SIM300 is a Tri-band GSM/GPRS engine that works on

frequencies EGSM 900 MHz, DCS 1800 MHz and PCS1900 MHz. SIM300 provides GPRS

multi-slot class 10 capability and support the GPRS coding schemes CS-1, CS-2, CS-3 and

CS-4.

With a tiny configuration of 40mm x 33mm x 2.85 mm , SIM300 can fit almost all the space

requirement in your application, such as Smart phone, PDA phone and other mobile device.

The physical interface to the mobile application is made through a 60 pins board-to-board

connector, which provides all hardware interfaces between the module and customers boards

except the RF antenna interface.

The keypad and SPI LCD interface will give you the flexibility to develop customized

applications.

Two serial ports can help you easily develop your applications.

Two audio channels include two microphones inputs and two speaker outputs. This

can be easily configured by AT command.

SIM300 provide RF antenna interface with two alternatives: antenna connector and antenna

pad. The antenna connector is MURATA MM9329-2700. And customers antenna can be

soldered to the antenna pad.

The SIM300 is designed with power saving technique, the current consumption to as low as

2.5mA in SLEEP mode.

The SIM300 is integrated with the TCP/IP protocolExtended TCP/IP AT commands are

developed for customers to use the TCP/IP protocol easily, which is very useful for those data

transfer applications.



7.3 PROGRAM CODE

#include

#include

#include

#include"pic_lcd4_msb.h"

#include"pic_adc.h"

#include"usart.h"

#define _XTAL_FREQ 4000000

int powerfactor()

{

int a=0,b=0,t=0,x=0;

float tm,pf;

TMR1L=0;

TMR1H=0;

do

{

if(RB0==1)

{

TMR1ON=1;

}

else if((RB0==0)&&(TMR1ON==1))

{

TMR1ON=0;

break;

}

}while(1);

a=((TMR1H*256)+TMR1L)*2;

TMR1L=0;

TMR1H=0;

do

{

if(RB0==1)



{

TMR1ON=1;

if(RB1==1)

{

TMR1ON=0;

break;

}

}

}while(1);

b=(TMR1H*256)+TMR1L;

tm=b/a;

pf=cos(tm*2*3.14);

x=abs(ceil(pf*100));

return(x);

}

void string(char *c)

{

while(1)

{

TXREG=*c;

while(TXIF==0);

__delay_ms(20);

c++;

if(*c=='\0')

break;

}

}

void enter()

{

TXREG=0X0D;

while(TXIF==0);

TXREG=0X0A;

while(TXIF==0);

}



void main()

{

int x=0,y=0,q=0,r=0,a=0,b=0,c=0,m=0;

TRISA=0xFF;

TRISB=0x03;

PORTB=0x00;

TRISC=0X83;

PORTC=0X00;

T1CON=0x0F;

ADCON1=0x80;

Lcd4_Init();

TMR1H=0;

TMR1L=0;

while(1)

{

RC5=0;

RC3=0;

x=Adc10_Cha(0);

y=x/2.67;

Lcd4_Command(0x01);

Lcd4_Display(0x80," voltage ",9);

Lcd4_Decimal3(0xc0,y);

Lcd4_Display(0xc3," v ",3);

__delay_ms(50);

TXREG='v';

while(TXIF==0);

TXREG=y;

while(TXIF==0);

TXREG='w';

while(TXIF==0);



a=Adc10_Cha(1);

b=a*10;

Lcd4_Command(0x01);

Lcd4_Display(0x80," current ",9);

Lcd4_Decimal2(0xc0,b);

Lcd4_Display(0xc2," A ",3);

__delay_ms(50);

TXREG='i';

while(TXIF==0);

TXREG=b;

while(TXIF==0);

TXREG='j';

while(TXIF==0);

TMR1H=0;

TMR1L=0;

__delay_ms(1000);

q=TMR1H*256;

r=q+TMR1L;

Lcd4_Command(0x01);

Lcd4_Display(0x80," frequency ",11);

Lcd4_Decimal2(0xc0,r);

Lcd4_Display(0xc2," hz ",4);

__delay_ms(50);

TXREG='f';

while(TXIF==0);

TXREG=r;

while(TXIF==0);

TXREG='g';

while(TXIF==0);

c=powerfactor();

Lcd4_Command(0x01);



Lcd4_Display(0x80," power factor ",14);

Lcd4_Decimal3(0xc0,c);

Lcd4_Display(0xc3," % ",3);

__delay_ms(50);

TXREG='p';

while(TXIF==0);

TXREG=c;

while(TXIF==0);

TXREG='q';

while(TXIF==0);

if((y>=229)||(b>=5)||(r>=50)||(RC4==1))

{

while(RC4==1);

RC5=1;

RC3=1;

string("AT");

enter();

__delay_ms(500);

string("AT+CMGF=1");

enter();

__delay_ms(500);

string("AT+CMGS=\"9809779967\"");

enter();

__delay_ms(500);

string("some parameters have exceeded the limits\maintanence mode

");

enter();

__delay_ms(500);

TXREG=0X0D;

while(TXIF==0);

TXREG=0X1A;

while(TXIF==0);



__delay_ms(5000);

while(m==0)

{

if(RC2==1)

{

while(RC2==1);

m=1;

}

}

}

}

}



7.4 PCB PREPARATION

PROCEDUREFOR MAKING THE PCB

PREPARING OF LAYOUT

With the diagram and all the components at hand, draw a complete layout plan of the

circuit on a sheet of a tracing paper. As a model, for laying the circuit, a thermo Cole base

may be used to hold components. Avoid overcrowding of components while making full

space utilization. Keep the ground line on the side of the PCB and the supply line on other

side as far as possible. When all the components have been mounted on the tracing paper

sheet fixed on a piece of thermo Cole base, take out a Sketch Pen for making in such a way

that all the connecting wires are equal in width, termination rounded off. Re-draw it on a

fresh paper if required.

PAINTING OF PCB

The tracing so prepared has to be imposed over the copper printed circuit board keeping

in view that the component would be mounted from the non-clad side of the board. Take a

PCB lamination sheet and cur a piece of required size of the board by using hacksaw file

edges, put the copper clad sheet on the table keeping side on the runway the dirt grease and

oxide with a sand paper with its marked side tracing the carbon paper and other side on top.

Since the tracing paper is transformed you can now reproduce a carbon point over a surface

but using ball pen on a hard pencil over the drawing on the transparent side. When the carbon

print has been obtained over the copper clad board drill ropes in the board using a hand drill.

The holes may be draw with 1/32 bit for component leads and the carbon should be raised or

wiped by mistake. Paint the connecting lines with the help of an ordinary paint. Edges should

be scratched with tip of razor blade or lamination knife edge.



DEVELOPMENT OF THE PRINTED CIRCUIT DIAGRAM

After painting the board, it will be made by the cool air for some time. Now take a

plastic tray and get some Fe Cl3 chemical powder. The ferric chloride salt is then added with

500ml of water. The color of the solution is pink. Color of the salt is in yellow. Now we add

three to five drops of dilute HCL or H2S04. This is necessary to quicken the process.

ETCHING OF PCB

Now we take the painted copper clad board and dip it in the solution kept in the

tray. After 15 to 25 minutes we see the board, with only printed pattern portion remaining in

other places the copper coating is removed due to the chemical action. Then the board is

taken out and washes in water. After wash the board by using thinner solution. Now a

printed circuit has been formed on the board.

Take fresh water and mix a few teaspoons of Fe CL3 add a few drops of dilute HCL to it,

as it speeds the etching process. Shake well immerse the PCB in the solution for about 20

minutes occasionally altering the solution by giving the seesaw reaction to the disk storing

reduces the etching time. Observe the changing color on the copper surface. Take out the

PCB only when the unpainted portion of the copper surface is completely dissolved in the

solution wash the PCB with the water. After the PCB is thoroughly washed remove the paint

by soft pieces of the cloth dipped in thinner or turpentine.

DRILLING OF HOLES

Then take a drilling machine with 1/32 drill bit to make holes for the incretion of the

components use 1/18 drill bit for inset wires and other thick components. Now the PCB is

ready to use.



MATERIAL REQUIRED

1. Copper clad sheet [It is made of nylon board Over which the sheet of copper is

pressed.]

2. Paint or Nail polish or even PCB Ink.

3. Painting brush, tray.

4. Ferric chloride solution and also few drop of dilute HCL or H2SO4.

5. Thinner or kerosene or petrol.

6. Cotton cloth.

7. Trace paper.

ADVANTAGES

1. Reliability in operation and low cost.

2. Space required becomes less.

DISADVANTAGES

It cant withstand larger weight such as transformer.

SCADA

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Transcript of SCADA