SCADA SYSTEM IN VISAKHAPATNAM STEEL

PLANT

A Project report submitted in partial

fulfillment of the requirements for the

award of

Bachelor of Technology

In

Electronics and communication

Engineering

Submitted by

K.S.GAYATRI R.ARUNA

SHEIK NAGOOR MEERAVALI

Y.VENKATA RAMANA Y.ARUNA

KUMAR

Under the Guidance of

B.KRUPANANDAM

Manager(Telecom)

Visakhapatnam Steel Plant

Visakhapatnam

ST.THERESSA INSTITUTE OF ENGINEERING AND TECHNOLOGY

(Affiliated to JNTU)

GARIVIDI

CERTIFICATE

This is to certify that the Project work entitled “ SCADA system in

VSP” is a bonafide record of work done by Y.Venakta Ramana,

K.S.Gayatri, Shaik Nagoor Meera Vali, R.Aruna and Y.Aruna Kumar,

students of St.Theressa Institute of Engineering and Technology, Garividi

have been sincere, dedicated and the conduct throughout the study has been

excellent in partial fulfillment of the requirement for the award of degree in

BACHELOR OF TECHNOLOGY under the guidance and supervision in

VISAKHAPATNAM STEEL PLANT.

Visakhapatnam Signature of Guide

Date :

ACKNOWLEDGEMENT

We hereby take this opportunity to express our sincere gratitude to the

following eminent personalities whose aid and advice helped us to complete

this project work successfully without any difficulty.

We are thankful to Mr. B.Krupanandam, Manager (Telecom) who has

been with us all through the project to spend his valuable time and to share

his knowledge.

As a token of our feeling, we would like to acknowledge our sincere

regards to our internal guide Mr. B. Vijaya Bhaskar Rao and our HOD Mr.

B.Rajesh Kumar, for allowing us to take up a project in a working plant we

express our gratitude to Sri.V.V.Narayana Murthy (Principal) STIET and

Sri. M.Sreenivasa Rao (Correspondent), for their cooperation during the

project period. We are also thankful to faculty members for their kind

cooperation and assistance.

INDEX

Abstract

Major Department of Visakhapatnam Steel Plant

Different Communication Systems in Visakhapatnam Steel

Plant

Introduction

Supervisory control and data acquisition system -

Architecture

Remote telemetry unit (RTU) – Block Diagrams

Modems

Cables

Master Station

Power supply requirements and specifications

Software

Conclusion

ABSTRACT

In this modern world of Industrialization and automation, energy

plays a major role in the growth of any organization. The utilization of

energy plays an impacting and direct role in the growth of organizations like

Visakhapatnam Steel Plant.

In Vizag Steel Plant, there is a supervisory control and data

acquisition system (SCADA) present for monitoring of energy networks

which are present through out the plant. The objective of this proposed

SCADA system is to monitor the energy usage and demands of various

consumers of the plant and exercise effective control over their energy

consumption optimum utilization of in-house energy resources.

In this modern world of competition, the technology is changing very

rapidly. To compete with the changes and to sustain the development,

Visakhapatnam Steel Plant is going for upgradation of its existing SCADA

system with the latest state of art – technology with the features like using

high speed processors having cache – memory and using the powerful unix

based OS.

This project makes a brief study of existing “SCADA” system present

in Visakhapatnam Steel Plant and the changes that are going to come to in

the proposed SCADA system that is to be installed in the near future.

GROWTH AND IMPORTANCE OF STEEL

INDUSTRY IN INDIA

Steel comprises one of the most important inputs in all sectors of economy. Steel

industry is both a basic core industry. The economy if any depends on strong base of iron

and steel industry in that nation. History has shown base of iron and steel industry in that

nation.

History has shown that countries having a string potentiality for iron and steel

production have played a prominent role in the advancement of civilization in the world.

Steel is such a versatile commodity that every object we see in our day to day life has

used steel either directly or indirectly.

However its use is innumerable to mention a few, it is used for such small items as

nails, pins, needles, etc., through surgical instruments, agricultural implements, ships,

boilers, frigates, railway materials, automobile parts etc., the great investment that has

gone in to the fundamental research in iron and steel technology has helped both directly

and indirectly many modern fields of today's civilization without steel. Steel is versatile

and indispensable item. The versatility of steel can be traced to mainly three reasons:

It is the only material item, which can be conveniently produced in tonnage

quantities.

It has got very good strength coupled with ductility and malleability.

Its property can be changed over a wide range.

It alloys easily with many of the common elements.

The properties can be manipulated to any extent by proper heat treatment

techniques.

Taking these factors in to consideration, it can be said without committing a

serious error, that the types of steel available are innumerable.

"Visakhapatnam steel plant is an integrated steel plant."

CHARACTERISTICS OF INTEGRATED STEEL PLANT:

This integrated steel plant has large capacities, highly capital intensive, labour

intensive and they would have all facilities including raw material resources, water

supply, power supply, testing and inspection facilities, township facilities, medical,

educational recreational etc., all under one administrative control. This would reduce

the extent of dependency on outside agencies, which would help the smooth running of

the plant.

TECHNOLOGY IN STEEL PLANT:

Visakhapatnam steel plant is the most sophisticated and modern integrated steel plant

in the country. Modern technology has been adapted in the many areas of production,

some of them for the first time in the country, among these are :

Selective crushing of coal.

Evenching of coke

Conveyor charging and bell less top for blast furnace.

100% continous casting of liquid steel.

Gas expansion turbine for power generation utilizing blast furnace top gas pressure.

Hot metal desulphurization.

Etensive treatment facilities for effluents for ensuring proper environment protection.

Computerization for process control.

Sophisticated, high speech and high production rolling mills.

HALL OF FAME:

Visakhapatnam steel plant has the distinction to be first integrated steel plant in

India to become a fully ISO9002 certified company. The certificate covers the quality

systems of all operational, maintenance, service units. Besides purchase systems,

training and marketing functions spreading over regional marketing offices,20 branch

offices and 22 stock yards located all over the country.

Visakhapatnam steel plant by successfully installing and operating efficiency

Rs.480 crores worth of pollution control and environment equipments and converting

barrel landscape by planting more than three million plants has made the steel plant

township and surroundings in to heaven of greenery.

Visakhapatnam steel plant exports quality pig iron and steel products to Srilanka,

Myanmar,Nepal, Middle East ,USA and South East areas.RINL- Visakhapatnam steel

plant was awarded "STAR TRADING HOUSE" status during 1997-2000. Having

establishing a fairly dependable export market.

Having a total man power of 17250 Visakhapatnam steel plant has envisaged a

labour productivity not less than 230 tonnes of liquid steel per man, which is the best in

the country and is comparable with the international levels.

MAJOR DEPARTMENTS OF

VISAKHAPATNAM STEEL PLANT

RAW MATERIAL HANDLING PLANT(RMHP):

The RMHP receives the basic materials required for the steel making process from

various sources through wagons which are stacked and reclaimed by stackerd and

reclaimed by stackers-cum reclaimers and distributed to various departments of

Visakhapatnam steel plant through conveyor systems.

COKE OVENS (CO):

Coke is a hard, porous mass obtained by fractional distillation of coal in the absence

of air at a temperature above 200deg.centigrade for period of 16 hrs to 18 hrs. It is used

as a fuel and reducing agent of iron ore in blast furnace. Three coke oven batteries for

production of 2.26 MT dry coke, each with 7 meters tall 67 ovens. Each battery is

provided with facilities for dry cooling of coke using nitrogen as quenching media for dry

cooling of coke as well as for recovering sensible heat of coke. As a by-product a CO

gas is produced in this processes and this gas is having a very high calorific value for

about 2400-2700KCAl and is produced throughout the plant as a fuel.

SINTER PLANT:

Sintering is one of the most widely used and economic agglomeration techniques.

Sinter is a hard and porous lump obtained by agglomeration of fines of iron ore, coke,

limestone , and metallurgical waste. Sinter increases the productivity of blast furnace,

improves the quality of pig iron and decreases the consumption of coke rate. Two 312

square meter sinter machines with 420 square meter straight stand type coolers for annual

production of 5.26 MT sinter.

BLAST FURNACE(BF):

Pig iron or hot metal is produced in the Blast Furnace. The furnace is named as

BF as it is run with blast at high temperature and pressure of 1500 deg. C. Raw materials

required for pig iron and iron are iron making ore, sinter, coke, and lime stone. There are

two 3200 cubic meter blast furnace to meet 3.0 MT annual metal requirement. Each

furnace is designed for 205 at mg top pressure, and will be belt charged and equipped

with bell-less Paul-wurth top. Each furnace is provided with a set of four hot blast

furnace stoves designed for supplying air blast up to 1300 deg.C. Three turbo

blowers ,one for each furnace and one stand by common to both furnaces are provided

with 12 MW top pressure recovery turbo generating power. BF gas is produced from

each furnace is being cleaned in gas cleaning plant comprising dust catcher, high pressure

scrubber and is distributed through out the plant as a fuel.

STEEL MELT SHOP(SMS):

Steel is an alloy iron and carbon ,where carbon should be less than 2%.Hot metal

produced in B.F contains impurities like carbon, sulphur, phosphorous, silicon etc., these

impurities will be removed in steel making by oxidation process. These are the three L.D

convertors to convert hot metal in to steel. The steel melt shop complex comprising two

1300-ton hot metal mixers, three 130-ton LD converters (two operating) and six 4-stand

bloom casters. Each converter is being provided with gas cleaning plant for cleaning and

recovery of LD gas, which will be used as fuel in plant.

ROLLING MILLS(RM):

Blooms cannot be used as they are in daily like. These blooms have to be reduced

in size and properly shaped to fit for various jobs. Rolling is one of the mechanical

processes to reduce large size sections in to smaller ones. The cast blooms from CCM

are heated and rolled in to long products of different specifications like high capacity,

sophisticated high-speed rolling mills. The rolling mill complex comprises :

Light and medium merchant mill (LMMM)

Wire rod mill (WRM)

Medium merchant and structured mill (MMSM).

Each mill is well equipped with required number of walking beam furnaces for

heating of walking beam furnaces for heating of blooms or billets and except for wire rod

mills, each furnace is provided with evaporative cooling system for generation of steel for

plant consumption.

THERMAL POWER PLANT(TPP):

The estimated power requirement for V.S.P in 280 at 3.0 MT stages, the peak

load being 292 MW essential loads being 49 MW. The generating capacities 286.5

MW. A captive power having 3*60 MW turbo-generator sets and 5*330 ton/hr steam

generators. In this plant, 6000 Nm^3/min turbo blowers are being provided for supplying

cold air blast furnaces.

TYPES OF COMMUNICATION EQUIPMENT AVAILABLE

In this modern age of industrialization telecommunications plays a very important

role in coordinating the activities of various departments / sections and in achieving the

set targets and also in improving the performance of any organization. In Visakhapatnam

Steel Plant, different types of communication systems are being used to meet the internal

and external communication needs. These are broadly classified as follow:

a. General purpose communication systems.

b. Process communication systems.

c. Monitoring & Signaling Systems.

GENERAL PURPOSE COMMUNICATION SYSTEMS :

The following facilities are provided under category of general purpose communication

systems:

3000 lines Electronic Exchange in Plant.

2000 lines Electronic Exchange in Township.

100 lines Electronic Exchange in Visakha Steel General Hospital.

44 lines Electronic exchange in Hill Top Guest House.

2500 Lines Electronic Exchange of Bharat Sanchar Nigam ltd (BSNL) in Project

Office is catering to the needs of Plant area and Sectors-I to VII in township.

Another 2000 Lines Electronic Exchange of Bharat Sanchar Nigam ltd (BSNL) in

Township is catering to the needs of Sectors-VIII to XI in Township.

The 3000 Lines electronic exchange in plant and 2000 lines exchange in township

are having the following facilities:

Extension (subscriber) to extension call, Auto call back, Hot lines, Music on hold,

Reminder Alarm, Automatic line testing facility, Faults man ring back, Call consult

facility, Malicious call tracing facility, 3 party conference Facility and Howler Tone alert

etc.

All exchanges working in the steel plant are interconnected by means of junction

lines and have closed numbering scheme. For communicating with any subscriber of any

exchange no extra digits have to be dialed and only the desired number is to be dialed. –

connection pattern given at fig 1.

The 2000 lines exchange in township is interconnected to the BSNL network. Due

to this interconnection all the subscribers of this exchange can receive incoming calls

from any part of the world. A few subscribers are provided with facility to contact

subscribers connected to the BSNL network and cellular and mobile phones in and

around Visakhapatnam.

PROCESS COMMUNICATION SYSTEMS :

To facilitate coordination, operation & management activities of production,

maintenance & service departments, the following process communication systems are

provided:

a) Despatcher communication system

b) Loudspeaker intercom systems

c) Loudspeaker broadcasting systems

d) Loudspeaker conference communication system

e) Industrial public address system

f) Hotline communication systems

g) VHF communication systems

A) DESPATCHER COMMUNICATION SYSTEMS:

Initially cordless switch board type manual exchanges of electromechanical

version were provided. Since manufacture of such systems and their spares is

discontinued in the country, these despatcher systems are being replaced by Electronic

exchanges progressively. Except the ones in CCCP other systems have been replaced.

These would also be replaced very soon.

Production coordination at plant level being conducted by ED (Works) with all

HODs in the morning every day is facilitated with the help of the digital EXCOM system

provided in the plant control room.

B) LOUDSPEAKER INTERCOM SYSTEMS:

Loudspeaker intercom systems are working LMMM & WRM. These systems are

used for communication between various sections of the same production shop.

Communication is made possible using microphones and loudspeakers provided in the

subscriber stations. This system is very useful in noisy environment where conventional

telephones are ineffective. This system helps to establish communication between any

two stations having interconnectivity on selection basis. By using group call facility it is

possible to communicate to all the subscribers in the group at a time.

c) LOUDSPEAKER BROADCASTING SYSTEMS:

Loudspeaker broad casting systems are provided in C&CCD, BF, SP and SMS

departments. This system is useful to make general announcements to the entire area of

working and so can be used to locate operation / maintenance personnel working on the

shop-floor so as to pass-on important instructions from the control room.

D) LOUDSPEAKER CONFERENCE COMMUNICATION SYSTEMS:

Loudspeaker conference communication systems is working in CCCP. These

systems are provided with both paging and private channel communication facilities. In

case of paging a general announcement can be made which is heard on all the stations. In

the private mode communication is possible between two selected stations only. Here

also communication is carried out by means of microphones and loudspeakers provided

in the subscriber stations.

E) INDUSTRIAL PUBLIC ADDRESS SYSTEM:

Industrial Public Address System is working in TPP. It is a combination of

loudspeaker broadcasting system and conference communication system. From the main

control room it is possible to make announcements which are heard on the shop-floor.

From certain locations the communication can also be established through handsets in

private mode with the main control room.

F) HOTLINE COMMUNICATION SYSTEMS:

To ensure direct telephone communication between closely related critical

locations hot lines are provided. By using the hot lines specified locations are connected

permanently. Communication is possible only between these two locations. When one

subscriber lifts his telephone the other will immediately get a ring and communication

can be had without any loss of time. This is useful to pass-on urgent messages. These hot

lines are initially provided with direct line communication systems which are electro

mechanical systems. Due to obsolescence electronic systems are now being used for most

of the locations. Hot lines are working in CCCP, BF,SMS, LMMM, WRM, MMSM,

TPP, PPM, DNW and WMD departments.

G) VHF COMMUNICATION SYSTEMS:

VHF communication systems are used in our plant to establish two way

communication between two or more when either or one of them is moving. There are

three models working in our plant. They are hand-held units (walkie-talkie), vehicle

mounted – mobile units and base station units. Walkie-talkies are used by operation and

service personnel in almost all of the production shops. Vehicle mounted units are being

used by DNW, CISF (Fire) and CISF (security). Base station units are used by CISF

(fire), CISF (Security), Administration, DNW and largely by CCCP departments. In

CCCP these can be seen in pusher cars, charging cars, door extractors, electric locos,

lifters and CDCP area.

MONITORING AND SIGNALING SYSTEMS :

To facilitate monitoring production, maintenance & service activities, the following

monitoring and signaling systems are provided:

a) Closed Circuit Television Systems (CCTV):

b) Central fire alarm signaling system

c) SCADA system

d) Shift change Announcement Siren System

A) CLOSED CIRCUIT TELEVISION SYSTEMS (CCTV):

For monitoring critical operations in different production units continuously from the

concerned control rooms / pulpits CCTV systems are used in SP, BF, SMS, LMMM,

WRM and MMSM departments. CCTV system comprises of CCTV camera with a lens

and a CCTV monitor. In some cases a video switcher, a central control console, pan and

tilt head and zoom lens are also used. These are interconnected by means of control

cables and / or coaxial cables Necessary protection is provided for the CCTV equipment

depending on the locations where they are used

B) CENTRAL FIRE ALARM SIGNALING SYSTEM:

The central fire alarm system is provided for communicating the exact location of

outbreak of fire in any part of the steel plant complex to the central fire station and

simultaneous actuation of sirens to alert personnel of the affected plant zone. The system

employs manual call points located all over the plant.

c) SCADA SYSTEM :

To monitor the consumption of energy by various users in the plant SCADA system is

provided. This is placed at Energy and Telecom centre. The system comprises of a master

station equipment with supervisory consoles and mimic panels located in the Energy &

Telecom Building, 23 Nos Remote Telemetry Units (RTUs) installed in different plant

units and 3 local RTUs for driving the mimic panel in the Energy centre. The RTUs will

be collecting the signals from the local instrumentation & electrical systems and

transmitting to the master station by means of RTUs. The RTUs are connected to the

master station by under ground telephone cables.

D) SHIFT CHANGE ANNOUNCEMENT SIREN SYSTEM:

The shift change announcement siren system is provided for ensuring uniform and

accurate shift timings throughout the plant. This system consists of two(2) nos quartz

crystal controlled master clocks in the Energy & Telecom Centre. The shift timings are

programmed in the Master Clock. At the specified time, the signal will be transmitted for

energizing the sirens located at strategic points in plant area simultaneously at the preset

timings.

Apart from the above facilities Telecom department maintains the following cable

networks also

a) DATACOM cable network in plant

b) Telephone cable network in plant and township

INTRODUCTION

Acronym for supervisory control and data acquisition, a computer system for

gathering and analyzing real time data. 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. A SCADA system gathers information,

such as where a leak on a pipeline has occurred, transfers the information back to a

central site, alerting the home station that the leak has occurred, carrying out necessary

analysis and control, such as determining if the leak is critical, and displaying the

information in a logical and organized fashion. SCADA systems can be relatively simple,

such as one that monitors environmental conditions of a small office building, or

incredibly complex, such as a system that monitors all the activity in a nuclear power

plant or the activity of a municipal water system.

SCADA systems were first used in the 1960s.

CENTRAL SUPERVISORY CONTROL AND DATA ACQUISITION

SYSTEMS :

The system comprises of Micro VAX ll based Master station equipment with

supervisory controls and mimic panels located in the energy and telecom building

and 23 RTUs installed in different plant units and 3 local RTUs for driving the mimic

panel in the energy centre . The RTUs will be connecting in the signals from the

instrumentation and electrical systems and transmitting to the Master station when

polled by the latter. The RTUs are connected to the master station by under ground tele

phone cables . Supervisory controls are also provided in MRS & EMD departments in

area shop office of utilities .

The system enables continuous monitoring of the energy networks in the steel

plant and generation of reports as required for taking strategic decisions in times of

crisis . The maintenance of RTUs mimic panel and the cable network between the

field / local RTUs & modem panel in the Master station is carried out by the telecom

department .

The signals for a plant unit will normally be concentrated in the control room

of the unit from where the unit is being operated . RTUs of the CSCS will be in

stalled in these main control rooms and the tele -- transmission signals identified for

the units will be wired to the RTUs . The RTU are called as Remote terminal /

telemetry units.

The RTUs are micro processor based intelligent units , responsible for

Acquisition of inputs from the plant units and convert them in to digital code for Tele

-- transmission to the Master station computer of CSCS through the 5 pair telephone

cable . Some plant unit where few signals are available for tele – transmission , A

junction box will be installed in the control room ( instead of an RTUs) for the

termination of inputs and these inputs are furthur connected to the nearest RTUs

through the multi – core control cables.

The system consists of computer based Master station with dual hot Stand

by computers . The peripherals like terminals , printers , communication Ports etc…

which are common requirements for the computer system are Connected through a

peripheral transfer switch ( PTS ) to the computers . The 23 RTU s are located in

different parts of the plant are connected to the center Master station through modems

in a multi dropped fusion to different channels Of communication controller . The

Master station located in the Central Dispatcher station ( C D S ) of the

Visakhapatnam steel plant will acquire all Information through RTU and

communication controller module ( CCM ) and Process the information for displays

and report generation .

The SCADA system shall acquire various electrical & utility parameters for

effective monitoring & control operation . The various parameters acquired shall be

such as electric power , voltages , currents , etc… under electrical monitoring and

parameters such as flows , temperatures, pressures , etc … for operation and

functional convenience the system categorized in to 2 following systems.

Utility systems

Electrical systems

UTILITY SYSTEMS :

The utility system covers the services like fuel , gases , stream , comprised

air, water etc…. The services covered by the utility systems of CSCS are

broadly classified in to following groups.

Fuel gases system : CO, BF ,Mixed & converter gases.

Process gas system : Nitrogen, Oxygen ,Argon, Acetylene.

Stream Distribution system: Stream at 40 KSCG,13 KSCG.

ivCompressed air system: Compressed air and instrumentation grade air

Chilled water system: Chilled water.

Fuel oil system : LSHS,LDO and LTF.

Water systens: make up water, fire and drinking water.

ELECTRICALSYSTEM

The electrical system covers the complete electrical distribution network

Inside the Visakhapatnam steel plant like 220 KV ,11 KV, 6.6 KV systems in

MRS, LBSS , 1, 2 , 3 , 4 and 5 , LBDSS , HVLCS and HUMCCS.

For centralized super visory of above services in utility and electrical systems

and also to exercise control over their optimum utilization ,following types of signals are

considered for the uses .

Analog input (AI)

Digital input (DI)

Analog output(AO)

Digital output (DO)

Pulse input (PI)

The input signals acquired by the RTUs are tele-transmitted to the Master station

and are sorted out according to the above subsystem division i.e utility and electrical. The

MS is provided with separate operator stations for utility &electrical system for

independent operations.

SCADA systems monitors a total no 5000 different signals originating at

different dept in VSP. Among these 5000 signals 1500 signals are catered to monitor

utility system and 3500 signals are electrical system.

The CSCS MS hard ware comprising of Micro computer, Peripheral devices

like operator stations, printers & power suppl unit like U P S , batteries, distribution

board will be housed in the second floor of the CDS building where separate rooms with

A.C facilities are provide in VSP.false flooring is provided for inter connection cables.

Full graphic type of mosaic wall boards one for utility system and another for

electrical system displaying the distribution network of various services and power flow

inside the VSP envisaged. The wall boards are located in thr main control room of the

supervisory center where the operator consoleof the CSCS is located.

There are interconnecting cables between

# RTU and the MS.

# Junction box and the RTU.

# Remote video terminals and MS.

Modems are provided for both th ends of communication link for inter

connection of Remotely placed units to the MS.These are placed to make up the cost

potential in the line .

Software in the Ms is also required to meet all the functional requirements such

as data acquisition,display, reporting ,trending ,performing application programs etc….

The maintenance of RTUs mimic panel and cable network between the field /

local RTUs and the modem panel in the MS is carried out by the telecom dept.

REMOTE TELEMETRY UNIT (RTU)

The micro processor based RTU s are installed at various plant Units.

The RTUs will be collecting the signals from the local Instrumentation &

Electrical systems and transmit to the MS when they are polled by the latter.

The RTUs are connected to the MS by under ground telephone

cables with ac MODEMS at MS end and dc MODEMS at RTU end.

OUTSTATION RTU HARDWARE:

The RTU H/W has the following contents:

(1) RTU cabinet

(2) Gland plates / field cables

(3) Terminations and interprosing relays

(4) Basic Tier

(5) I/O Tier

(6) Power Supply Arrangements

(7) Basic Modules

(8) I/O Modules

(9) RTU I/O configuration

RTU CABINET :

The RTUs are houses in standard fabricated steel cabinets of Rugged

construction.

The RTU cabinet has an internal structure for:

# Routing the field cable to the terminations.

# Mounting the terminations and interprosing relays.

# Routing the I/O cables from the termination and

interposing relays to the electronic tires.

# Mounting the electronics comprising PCCs fitted in tires.

# Mounting the Power supply unit for providing the logic supplies

to all cards.

The genrnal layout of the RTU cabinet is attached.

A signal cabinet can accommodate a basic tier and an I/O tier. If

further expansion requires two I/O tiers can be added.

GLAND PLATES / FIELD CABLES :

All external connections to the RTU enter the cabinet through Gland plates.

The external connections are communications connection, Power connection and

mainly the field cable connecting to the plant Instrumentation.

Termination & interposing relays :

The field cables entering the RTU are terminated on screwed

Terminals mounted on vertical rails. The interposing relays are plug in type and are

accommodated in power supply

cabinet installed adjacent to RTU cabinet.

The interposing relays are provided where the output control Logic

power is not sufficient to operate a high voltage and current Points.

The connections are made by standard multicore twisted paid Cables

and gold ribbon connectors.

Dia : Testing of in coming signals to RTU from field.

BASIC TIER :

The basic tier is fitted at the top of the cabinet . It houses

1. The basic cards comprising microprocessor card (MP 3) the Analog/Digital

converter (ADC 4) and the master control / test Cards (MCT 2).

2. Upto 8 input / output cards.

3. Power supply Adapter card to distribute the supplies to PCBs.

INPUT / OUTPUT TIER :

The input / output tier is fitted below the basic tier and can

Accommodate upto 19 input / output cards.

POWER SUPPLY ARRANGEMENTS :

All RTUs are provided with 230 KV AC operation. The RTU Power

supply unit operates on 24 V DC input and generates all logic Supplies +5V, +12V

and -12V required for the oprations of the RTU. The input 24 V DC is derived

from local mains power supply with a Battery back –up provisiopn with

maintenance free sealed lead acid batteries for 8 hours.

BASIC MODULES :

a) Micro Processor Module (MP 3) :-

The MP 3 is a signal printed circuit board designed for general Use in

telecontrol systems to provide intelligence at the out station, Master station front

end to the main computers telecontrol test Equipment and standby system

operation.

# The units is based on 8 bit Motarola M6800 micropocessor.

# The module incorporates a maximum of 8K bytes of PROM

and 4 K bytes RAM.

# The data acquisition, data processing, communication and

housekeeping information of the RTU are performed using

this module with memory.

# This card provides I /O bus catering to the I /O modules end

serial communication interface to modem for communication.

The logic requires the following supplies for a fully fitted card +5

at 2A, +12V at 0.3A and -12V at 0.15A.

# Facility has been provided for memory extension.

b) Master control test card ( MCT 2 ) :

# This module provides the number of RTU house keeping and

security checking functions.

# This card is degigned to fit a standard I / O card position.

# Main functions :

# Supply of powre to state control relays with local isolation

racllities.

# Generation of check logic pattern on a spection monitor

adderss.

# Generation of ADC calibration check reference voltage .

LEDs are provided to indicate controls.

Internal power required +12V at 28mA

+12V (HU) at 1mA

+15V (ISOL) at 1mA

External power required 24 V or 48 V.

c) Analog to digital conversion card ( ADC 4 ) :

This card provides successive approximation A / D converter which

Converts 1- 5 volts full scale into 11 bits plus sign digital value.

# This card is used to convert analog input signals into digital

binary data (2’s complement or unipolar or offset binary )

# Opto Isolater s -> to form a barrier between the floating

analog conversion side and an 8 bit moniter high way.

# Analog input are superimposed on common mode. Voltages

to be digitized. Maximum voltage is 50 V dc & value is –80 bd.

# A start conversion signal starts the ADS digitizing cycle and

resets the clock control at the end of conversion.

# When the cycle is complete, the digital data is transferred to

shift register and clocked out across the isolation barrier to a

second shift register. Then data transfer complete signal resets

the clock control and also generates an ADC interrupt / Resets

to indicate data is ready to transfer.

# The basic conversion time is 300ms.

# An ADC output enable signal enables the two- byte transfer

of digitized data on to the moniter highway .

First byte consists of 8 MSB bits includes sign bit ( if bipolar )

Second byte contains the 4 LSB bits.

I / O MODULES :

I/O module unit comprises of the following five I/O cards.

1. ANALOG INPUT MODULE (AMFS 3) :

The AMFS cardscales and filter 8 high level analog current or Voltage

input which are multipexed by relays on to a common output circuit .

# It accepts voltage or current input presented by the instrumentaion.

# The card multiplxexes 8 input to the ADC

# The card accepts either 4—20 m Amps or 1—5 Volts Signals .

# The card function address ( lower ) is set by switches or liens on

the card

# For an 8 bit A/D conversion 1 function adderss is required .

For more than 8 bit conversion 2 function adderss is required .

# In cases of Ms. 8 bits of each of 4 digitized values are allocated

byte position 0,2,4 and 6. The remainder of each value is placed

in the adjacent add byte.

# The card operates from a + 12 V source at 1mA .

( for CMOS Logic )

(2). STATE MONITER BARRIER ( SMB 11 ) :

The SMB 11 card provides an electrically isolated interface between 32

signal bit plant status inputs and an 8 bit monitor high way . Plant input is

typically a dry contract switching 24 volts ( negative ) to a filter , limiter and opto

isolators which gives 1500 volts plant to logic isolaction . The filter time constant

is nominally set to 10 mA . The current for each input is 5 mA and the 32 inputs

have a common positive return.

The card is addressred from a function highway and the 4 x 8 bit bytes

are selected by a slot highway . Function and addresses are set by switches or

links on the cards . When the card in addressed and strobed a card present

signal is generated .

The CMOS logic operates from a + 12 volt supply at 10 mA .

(3). STATE CONTROL BARRIER ( SCB 8 ) :

The SCB 8 provides 8 signal bite stae control output an 8 bit control

Highway . Electrical isolation is provided by the use of opto-isolators- ( 1500

volt isolated ) which provide an output of 100 mA at 24 V DC . An ‘on’ output

sinks into a common negative rail .

The card is addressed from an 8 bit function highway , the control

portion responding to four consecutive addresses each of which allows control

data to be latched in one or four 8 bit latches . Each 8 bit batch is associated with

a timer which will reset the controls after a pre--set time each opto—coupler

input is monitored using a signal monitor address along with the

appropriate slot address by a three ploe switch.

In each case the switches may be replaced by appropriate wire links .

Circuitry is provided to ensure that control security is maintained During

switch ON/OFF etc . These circuits are also associated with External control

allow and inhibit signals .

The CMOS logic operates from a 12 volt supply and requires 4 mA plus a

nominal 30 mA for each control energized .

(4). TOTALISER CARD ( TL 3 ) :

The TL 3 card count 4 independent pulse stream , in to 8 digit BCD

counters . Each total , 32 bits , can be read by the appropriate function address on

to the moniter highway in 4 byte each of 8 bits .

The card is addressed from an 8 bit function highway . which with A

strobe and slot address selects the appropriate total . each card Requires 2 or

4 function addresses . Switches are links on the card set

The lowest address when the correct funtion address is received a card present

signal is generated . Varlants of the card input pulses up to 50 V , and TTL

or variable level inputs . Each pulse stream has a maximum has a

maximum pulses of less than a duration set by the card variant .

Local reset is affected by 4 card mounted push buttons . Remote

Reset is provided is by the two LSB s on the control highway in

conjunction with current function address .

A fast count test facility , witch can be isolated by switches on the card , is

provided for each store .

The CMOS logic operates from 12 V supply at 8 mA , which may be Supplied

from external battery back up to hold the count when the Main supplies fail .

(5). ANALOG CONTROL ( AC 5 ) :

The AC 5 card stores and converts 8 bit digital word from a control

Highway in to current or voltage isolated outputs . Each card has four

independent D / A converters which provide the analog outputs when enabled

by the appropriate funtion address. The card has four consecutive control address ,

which are selected as a block by the 6 most significant switches or the card .

The card is addressed from a 8 bit function highway , which in

Conjunction with a strobe , allows the digital word on a control highway To be

read in and stored .

The stored outputs operate opto – electric devices which from an Isolating

barrier between the digital logic and the D / A converters . This

Allows the analog outputs to be operated from independent power

Supplies . The status of each store can be monitored via the Monitor Highway

on receipt of the appropriate function / slot address .

The latches can be powered from an independent 12 V hold up Supply

and during switch ON—OFF this supply the latches are set to give zero analog

output . This circuit is also associated with an external analog control inhibit

signal . A card present signal is indicated when the correct function is present .

The external load should be the range 250 — 500 ohms . The analog

output are isolated from the control logic and each other . The output circuits

required external isolated power supplies each of 24 V at 26 mA .The CMOS logic,

together with the op--to isolators ,operates from a 12 V at 1.2 mA when other supplies

are present and 2.2 mA when other supplies fail .

PRINCIPLES OF SYSTEM OPERATION :

The basic principle of this system of data transmission between the Master

Station ( MS ) and any particular RTU in either direction is time – division

multiplexing .

Where the MS has to communicate with a number of RTU’s

multidropped on a common communication circuit . this system normally uses

time — division multiplexing between RTU’s .This is achieved by use of the uniqe

outstation address encoded in the hardware of each RTU.

The basic of data transmission is the word . In interrogation mode the word

comprises two message , the interrogation message directed from MS to RTU s .

Each message comprises up to 32 bytes . The first byte contains RTU

addressing information . The second byte indicates message length. There then

follows a number of information and or status bytes and finally

A Bose - Chaudhury - Hoocquenhem ( BCH ) check character generated Over

the message using the generator polynomial .

X ^ 8 + X ^ 7 + X ^ 5 + X + 1

Each byte comprises a start bit ( logic zero ) eight data bits and byte

comprises A start bit (logic zero) , eight data bits and a stop bit (logic one ).

The Eight data bits are numberded 0 , least significant ( LS ) to 7 , most

Significant ( MS ) . Bit 0 is terminated to a serial communication channel first , bit

7 last .

INTERROGATION MODE WORD STRUCTURE:

Address byte: out station address.This is the unique address of the RTU being

interrogated.

Byte count Byte: this is the number of information bytes in the message.

Information bytes: function address and data bytes.These bytes may be used to transmit

information to the RTU, or to define which information to the RTU is to transmit back to

the MS.

Check byte: BCH code check.

Reply Message(13 bytes):

Address byte: outstation address. This is the repeat of the first byte of the interrogation

message.

Byte count byte: this is the number of information/status bytes in the massage.

Information bytes: function address and data where information has been transmitted to

the RTU ; these bytes are used as acknowledgement, which may include information

received by the RTU. When information is requested information is transmitted in these

bytes.

Status bytes: RTU status. This is a monitor of important RTU status conditions.

Check byte: BCH code check.

MODEMS

The multi-tech computers multi 748 A is a microprocessor controlled CCIT V.27

bits/tier compatable leased line modem. It can be operated at 2400 or 4800 baud, in either

two or four wire synchronous modes. Two-wire operation is only half duplex. The multi

modem 748 A incorporates fall back to 2400 baud when operating the V.27 internal DIP

switches, jumpers and modem commands control the mode of operation.

The multi modem 748 A uses 8 level DPSK modulation. The carrier frequencies are

1800 Hz at 4800 baud. The transmit level is adjustable from 0 DBm with the help of a

potentiometer given on the PCB. In asynchronous operation the character length is 10 bit.

The receiver sensitivity of the multi modem 748 A is 43 DBm.

Operation:

On power up or reset of the multi modem 748 A, the microprocessor reads the

operating parameters from either the DIP switch settings and ROM or if the user has told

options from RAM.

The speed switch on the front panel controls the speed of the data rate. The rate

of high and low speeds is determined by the mode of operation.

There are two blocks of DIP switches on the multi modem 748A circuit board

used for configuring various options. 8 positions and 4 positions DIP switch, are both

accessed from the bottom of the chassis.

INTERPOSING RELAYS

MODEMS :

PRESENT SYSTEM :

Presently the power supply (230 Volts AC) arrangement to the PSU and AC

modems (18 nos.), which are at MS, is taken from one breaker (5 Amps), which is in side

by system department room. This power supply is directly terminating in terminal strip

in loop as a loop out fashion. The PSU of AC modem is directly connected to another

side of the terminal strip. There is no ON / OFF control on PSU in order to do

maintenance or attend problem of PSU of AC modem. Working of AC modems are

intiable the functioning of CSCS. So in order attend complaint at power supply unit of

AC modem the main breaker has to switch off, which in turn causing total shut down of

CSCS.

PRESENT DIFFICULTIES:

The PSU arrangement to PSU of AC modems is in such a way that to attend the

complaint in one PSU of AC modem requires total shut down of CSCS does not permit

coordination and meeting the demands of the various in plant consumers and to exercise

effective control over their consumption for optimum utilization of energy resources.

More over permission for total shut down of CSCS is very lengthy process. The

main breaker, which is in systems department room, is not in convenient for maintenance

position.

PROPOSED SYSTEM :

In proposed system of power supply 230 AC arrangement to PSU of AC modems

has to take AC power supply from U.P.S and install one double pole, double breaker is

fed to 18 nos. of single pole breakers and output of breakers is connected to terminal

strip. At another side terminal strip it is connected to PSU neutral has to directly take

from double pole switch and it should connect to terminal strip directly in loop out put

fashion. All breakers should keep in one enclosed box and it should install nearby AC

modem rack. So while doing maintenance or attending problem in any PSU of any

modem it is easy maintenance people. Another important advantage is that avoids the

total shutdown of CSCS.

REQUIREMENTS :

To carry out the modification of the power supply arrangements to PSU and AC

modem of CSCS needs.

o One Double pole double switch

o Eighteen pole single switch.

o Eighteen, 50 mts multi strand

o Enclosures for installation of all these switches

o Locking arrangements

BENEFITS :

The modification in power supply arrangements to PSU of AC modems of CSCS

is mainly intended to increase the availability of system in generation.

This modification,

Eliminates the down time to total CSCS

Increases the optimum utilization of resources like fuel utilities and electric

power.

Helps in reducing specific energy consumption of steel.

Improvement in safety, quality of service

Ease in maintenance.

CABLES

Objective :

In both interrogation and broadcasting mode there is a continuous Transfer

of information between the RTU and the MS so there is a Necessity of a

physical medium to facilitate the flow of information

( Electrical Signal ) . Cables perform the job of interconnected the field

RTU’s and MS .

The inter connectig cables required for connecting various terminals Can be

clssified in to 3 categories and the technical specification of various cables are

also given below .

CATEGORY – I :

Telephone cables required for inter connection of RTU’s and the MS.

# 5Pair Petroleum jelly filled.

# Armored.

# Over all polythene packeted.

# Solid annealed high conductivity copper.

# Diameter 0.633mm.

# Resistance 57 ohm /KM.

CATEGORY-- II :

Twited pair cables rwquired for the inter connection of remote video

terminal to the master stations .

# 5Pair.

# Diameter 7/ 0.2 MM.

# Individually and over all shielded.

# Armored cables.

CATEGORY – III :

Control cables required for the inter connection of signals from plant units

and junction boxes to the RTU’s .

# Size 1.5 mm.

# Solid annealed copper conductor.

# Multi core control cable.

# Armored and unarmored.

# Thickness 0.8 mm.

# Resistance 12.1 ohm / KM.

# PVC Insulated.

The cables will be laid partly on cable trays in cable tunnels and

balance the directly buried under ground .

MASTER STATION

OBJECTIVE:

The Master Station located in the CDS building in VSP will acquire all

information through RTUs and CCMS and process the information for displays and

report generations which are very important at the times of crisis to take strategic

decisions.

The master station hardware comprises of the following:

Host computer Micro VAX II

Communication concentrator module(CCM)

S/3 intelligent colour console

Peripheral transfer switch (PTS)

DELNI

System Console

Magnetic tape subsystem

Hard disk subsystem

VT-320

Digitizer pad

Communication transfer switch

Common controller interface module

1. HOST COMPUTER:

The host computer is the main controlling element of the S/3 SCADA system. The

host contains the S/3 application S/W and is responsible for the bulk data storage

functions . The typical host consists of a computer unit ,tape and/or disk drives and alarm

types. The host computer is one of the Digital Equipment Corporations (DEC) VAX

family of general -purpose computers .

The VAX runs under VMS -Virtual Memory System operating system.

The S/3 application S/W runs under the direction of the VMS OS .All S/W

transportable from one VAX model to another, allowing host systems upgrades as the

application dictates .The current value from the RTU is sent to the host where it is used

to update a current value table CVT .The CVT is accessed by the color console S/W to

update value displays and by database access tasks. In addition the values from the CVT

are sent to the current trend , historical trend and achieve databases .

Redundant hosts are supported by the S/3 system. In redundant applications, both

hosts are updated with databases information and current values in order to

ensure a bump less transfer in the event or a system failure .

HOST COMPUTER OPTIONS:

There are several types of VAX computers available for the S/3 system.The size of the

computer is dependent on the actual S/3 system. Each VAX processor includes a CPU , a

memory management, Hardware, sixteen 32 bit internal general registers, 32 interrupt

priority levels and an I/O subsystem. External disk and tape devices augment processor

operation. The VAX features time sharing, virtual memory management, packed decimal,

fixed point and floating arithematic functions and a high precision programmable real

time clock.

1. Micro VAX ll :

The micro VAX is a small stand -alone micro computer system design system for

small S/3 system. The micro VAX contains Q-Bus based architecture with a 32 -bit

structure. The unit is supplied in a compact caster mounted cabinet , which provides rear

access to all cable connections. A 296 MB of internal RAM memory and houses dual 159

MB disk drives for program and mass storage.

2. Communication Concentrator Module (CCM):

The communication concentrator module functions as the communications interface

between the Host and RTU. The CCM also provides the interface link to external

programmable logic controllers-PLC or other external intelligent through an optional

foreign RTU interface board.

The CCM is a microcomputer, which performs the data acquisition function and stores

all the data in its buffer memory and upon the instruction from host transfers the required

data to the latter.

CCM is comprised of up to 4 functional blocks. An intelligent board is dedicated to

each of the functional blocks. The boards interface to each other through the CCM multi

use.

CPU Boards:

It is the controlling device in the CCM and is responsible for controlling all data

transfer functions within CCM

N1301B Ethernet Communications Controller Board :

This board accomplishes data traffic between the host and the CCM.

MCS-1062+Serial communications controller board:

This board accomplishes data traffic between the CCM and the RTU.

Foreign RTU interface FRI board:

The FRI board is a specially configured 86/35 or ODO01/0000 CPU board that is used

to interface with programmable controllers or other intelligent devices.

S/3 intelligent colour console:

The S/3 colour console serves as the main operator interface to the S/3 system.

The colour consoles main function is to provide the operator with a convenient method to

access process data and process parameters. All interaction with the S/3 system can be

accomplished through the colour console. In the terminal mode the console uses the DEC

command language DCL to access various host databases and A/3 files.

The colour console connects directly to the host computer to an RS-232/C serial

communications link. The console communication requests to the host and is capable of

accessing information for any point resident in the host's point database. Colour console

can also be installed directly on the ethernet or locally at an RTU. Consoles locally

connected to RTU only access information pertaining that RTU.

The colour console is a self-contained micro computer sub-system. All S/W tasks

and graphic data bases are resident on an internal hard disk drive. The unit handles all the

graphic formatting revealing the host of considerable overhead. The tasks running on the

console are self-sufficient and only require interaction from the hosts when accessing

current point values and alarm information.

Users present processed data on the console display in a variety of display

formats, which display the data in the most appropriate manner for efficient

interpretation. Displays are organised in a heirarchy and present data in varied levels

progressing from an entire plant overview down to single point display.Each display

includes pertinent information about the displayed data. Certain areas on the display are

reserved for the presentation of system and alarm messages.

Access to the displays and interaction with other console functions is

accomplished through console keyboard. The console keyboard is divided in to four

dedicated key pad areas, which provide access to all S/3 functions with a minimum

number of keystrokes. The provision exists to place the console in a VT series emulatoin

mode-terminal mode -tht allows data base management functions performed directly

from the console.

An S/3 graphics package is available to craete and use custom graphic display that

allow an operator to quickly and easily acquire data for complete process monitoring and

control. The custom graphic displays are in addition to the performated displays. The

custom graphic displays are created by the user can be customized for any application.

3. Peripheral transfer switch with watchdog timer:

The two number micro VAX2 host computers complete with working memory, bulk

memory units like hard disk, magnetic tape drive, floppy drive units and interface

modules etc., are connected in hot stand by redundant mode and the common peripherals

like S/3 video terminals remote video terminals remote video VT-320 terminals printers

communication interface parts etc., are connected to the host computers through the PTS

switch are shown in the diagram.

Normally the peripheral devices are connected to one of the host computers and that

computer performs as the main MS.Where as the other host remains in hot stand by mode

tracking and the main computer function.In the event of failure of main host,all the

peripheral devices are switched over to the stand by host through PTS and stand by host

stands functioning as the MS.

4. DELNI:

DELNI stands for Digital Equipment Corporation Ethernet Local Network

Interconnect. The CCM communicates with the host through an Ethernet communication

link. Communications traffic from the host is analysed by the CCM and directed by the

appropriated RTU. A multi bus to Ethernet communication controller board performs this

function in the CCM. The Ethernet communications link is routed to an Ethernet

interface, DELNI, for direct connection to the Ethernet network.

Ethernet Overview:

Ethernet is a basement local area network optimised for the high speed exchange of

data between processors. It was developed as a result of joint effort between DEC, Intel,

and Xerox in 1979. The ethernet specifications applies to the two lowest levels of overall

network architecture as defined by the ISO/OSI committee.

Physical layer:

It has a medium of shielded coaxial with manchester encoded digital baseband signalling

and data rate of 10 million bps. It uses a bus topology in the shape of a branching tree. A

maximum of 1024 nodes may be separated by up to 2.8Km.

Data link layer:

It is a multi accessed layer and is fairly distributed to all nodes. The access

method used for network devices employs contention control for when two nodes try to

transport at the same time and is known as carrier sense multiple access with collision

detection - CSMA/CD. Each Ethernet packet has a length from 64 to 1518 bytes with a

variable data field from 46 to 1500 bytes.

The physical and data link layers provided for delivery of a packet of data, or

datagram, between two nodes in a network. It is necessary to provide higher level

interfaces and protocols for complete application to application operation of the network.

These higher-level interfaces include:

Network management

Error recovery

Internet work communication

The application interface.

These layers correspond to top five layers of the ISO model. Digitals DEC net

products have integrated Ethernet in to its digital network architecture(DNA).

The physical components of Ethernet at the physical layer are the coaxial

cable(the carrier) , a tranceiver tied to an Ethernet communications controller.

The Ethernet controller also handles the data encapsulation, decapsulation and the

link management collision handling of the datalink layer.

5. System console:

The S/3 consoles located in the utility area shop office and MRS will be provided

with all the operation features like mimic diagram displays, alarm displays, operation of

remote control devices etc., as provided in the operator work stations. The command

signals for opening and closing of the circuit breakers in the electrical distribution

network are normally released from the S/3 console in the MRS.

The VT-320 video terminals and printers connected to each of the host micro

VAX2 computers normally function as system consoles. Through these system consoles,

basic system functions such as configuration, booting file management, system diagnosis

etc., are performed.

6. Magnetic tape sub system:

It consists of TQK 50 controller and TK 50 streamer tape of the capacity 95 MB.

7. Hard disk sub system:

It consists of one RQDK 3 controller and two RD 54 159 MB hard disk and one

RX 50 800 KB floppy disk drive.

8. VT 320:

The remote video VT 320 terminals are located in the area shop offices of the

different zones inside the VSP.

Normally the alarm conditions and important events pertaining to a particular zone

are reported to the respective area shop office terminals .Also special reports and logo

will also be routed to these terminals from the system whenever a request is made.

9. Line printer:

The LP 27, 1200 LPM line printer connected to the main host computer will print

the logging and reporting files of the system at the and of every shift, day, month etc.,

and also print special reports whenever a request is made.

10. Dot Matrix printer:

The LA 75 matrix printers which are a part of the operated work station of utility

and electrical system are normally used for printing alarms, event logging and operator's

action etc.

11. Digitizer Pad:

The digitizer pads and pens are provided in the operator work station, will be used

to generate customs graphicdisplays for the colour console. Graphic display generation is

greatly enhanced by the digitizer pad, at all the graphic components are selected directly

from the pad.

12.Communication transfer switch(CTS):

Communication transfer switch along with the watch dog timer module is used for

automatic change over between the redundant communication control modules.

13. Common Controller Interface Module:

Two number common controller interface modules KMI A provided in each host

computer will perform the data transmission between the supervisions control computer

and power plant computer and control planning computer. These modules one of micro

computer based intelligent units compising of a dedicated micro processor buffer

memory units and S/W blocks etc. For conversion of the data in to a required formatted

and transmission to other computers. The data transmission format confirming to X.25,

HDLC protocol will be adopted both at the supervision computer and central planning

computer ends fro perfect hand shaking between the computers.

POWER SUPPLY REQUIREMENTS AND

SPECIFICATIONS

OBJECTIVE :

The S/3 supervisory control and data acquisition SCADA system is a versatile

network of intelligent sub system like RTUs, cables, MS etc. all these sub system

contained hardware components, which require electrical power for their functioning.

There are wide range of hardware components present.

So it is the function of power supply unit to cater the needs of these components

with a wide range of power inputs.

MASTERSTATION :

For supervisory control center , a 415 Volts A.C., 3 phase , 50 hertz

Power supply feeder will be provided by Visakhapatnam steel plant in CDS For

power distribution to the MS hardware .

An U.P.S. if capacity 30 K VA with battery back up for 30 min . is

envisaged to provide a clean power to the hardware .

A dual U.P.S. each of capacity of 30 K VA complete With converts ,

Charges , invertors etc .. are connected in parallel in hot stand by mode . Under

normal conditions both U.P.S. are in line share the system load on A 50 % basis .

In the event of failure of 1 , the other will take over the full Load .

In addition to the hot stand by , a by pass regulating transformer / server

Control voltage stabilizer will also be provided along with the static switches ,

tracking devices etc., to supply at constant output voltage in the event of failure of

both U.P.S. systems .

A battery bank consisting of a group of lead acid batteries having the

voltage output of 240 Volts DC will be provided and capacity of battery bank

will be adequate to support the complete load for 30 min . in the event of mains

supply failure . The floating battery bank will be connected to the P.C input of

each inverter and maintain continity of AC Power output with out interruption

through the inverters . The battery charging will be automatic from the mains

supply and the charger will have provision for float charging and battery bank .

U.P.S SPECIFICATION :

INPUT:

Voltage : 415 V+ / -10 % AC 30 Phase

Frequency : 15 Hz +/- 5 %

Power Factor : 0.8 lag to 1

OUTPUT:

Voltage : 230 Volts AC 1 Phase

Frequency : 50 Hz

Voltage Regulation : +/- 1 %

Frequency Regulation : +/- 0.1 Hz

Line Sync. Rage : +/- 0.5 to 1 Hz ( adj )

Over Load Current : 125 % for 10 min.

150 % for 10 Sec.

REMOTE TELEMETRY UNIT :

The power supply cabinet which is installed adjacent to the RTU

Cabinet contains linear power supply ( LPS ) unit cum battery charger and Modem .

LINEAR POWER SUPPLY :

A linear power supply unit 1 provided with the RTU , which is a

standard 19- rack mountable unit mounted in the power supply cabinet . This unit

supplies 24 Volt DC supply to RTU as well as field .This supply

Will be uninterrupted when a battery is connected across the battery

Terminals . A charger is also incorported in the unit charge the batteries when the

AC supply is a available .

The unit on 230 Volt AC input 50 Hertz signal phase and 36 Volt

Battery connected at battery terminals .

DC -- DC CONVERTER :

GENERAL DESCRIPTION :

The power supply is a standard 19 – rack mountable unit mounted

Below the basic and input / output tiers in RTU cabinet . The output of This unit

is extended to the tiers through PSU adapter board with a suitable cable .

The unit provides logic requires for reqires for the operation of RTU from

a DC voltage sorce with an efficiency of 60 % ( typical ). The power Consumption

of the unit is 80 – 90 Watts typical providing 3 separate DC output each

giving 20 Watts DC to the load .

SPECIFICATIONS :

INPUT :

Voltage : 24 Volt / 48 Volt .

Tolerance : +20%

OUTPUT :

3 Isolated DC outputs : +5V&3A

: +120V & 1.5 A

: -12V& 0.5 A

Regulation : +0.2%

Ripple : less than 50mV ( peak to peak)

Input / Output : 24 KV rms

Operating temperature range : 0.55 deg. Celsius

Weight : Kgs.(Approx)

Dimensions : 465mmX 300mm

Efficiency : 50%

Storage temperature range :-25 deg.Celsius to +85 deg.Celsius .

Supply shall be switched OFF when the input voltage falls below

A limit lower than threshold on when the voltage falls below a limit lower

than threshold and shall be switched on when the voltage restored back to a level

above the limit i.e., upper threshold .

Insulation shall with stand for 1.5 KV DC between DC input terminals

shorted and earthed insulation shall stand for 250 Volts DC between output

and earth .

POWER SUPPLY CABINET

MODEM

FAN MODULE

LINEAR POWER SUPPLY UNIT

WITH BATTERY CHARGER

BATTERY HOUSING

SOFTWARE :

System is required in MS to meet all the functional requirements such

as data acquisition, display, reporting, bending and performing application

programs etc. ECIL responsible to install run and commission various

software modules in the system.

Multi programming also makes use of memory in better way. Since

one program will not normally be larger enough to occupy full memory.

Multiple programs make further use of memory.

Multi programming operating system is more complex than single

program operating system since it has to decide which programs are to

resident (Swapper), which programs will run next (scheduler).

Swapping : It means moving images back and forth between storage and

memory. In time sharing environment waiting program gets swapped out of

priority based environment.

Scheduling : It means deciding which program runs next. These are two

types

Priority Scheduling – Priority based

Time sharing scheduling – Round robin

VMS uses a combination of both systems.

Virtual memory : It is a mechanism of memory management which

combines limited physical memory and auxiliary stogie, give user an illusion

of vast amounts of main memory.

The operating systems take care of many of details of memory

management and programmer works in a symbolic virtual address space of

tremendous size.

Merits of virtual memory :

Memory efficiency

Protection

Relocation

Sharing

Demerits :

Overheads

Thrashing

COMMUNICATION SOFTWARE:

The CSCS exchanges vital data with two other computer systems i.e. the plant

central computer and power plant computer systems through data links for effective

integration between planning and supervisory levels.

The CSCS include 2 no.s KM VIA (communication processors with firmware

supporting X.25 defining HDLC as protocol) per micro VAX2. The communication

processor is able to handle all X.25 link level functions such as frame header generation,

error checking and retransmission.

S/3 databases:

Several databases reside in the host that is used to define the S/3 systems. These

databases exists in both off-line and on-line version. The on-line version is used to run

the current S/3 SCADA applications.The off-line version is the "master copy" of the

database. The S/3 databases are created by menu-driven utilities supplied as a part of the

S/3 applications. The databases reside at the host and are selectively downloaded to the

other nodes on the network as required. The following databases are a part of the S/3

system.

Network configuration:

It is the database that defines the S/3 network and the relationships that exists

between the different S/3 processes.

Asssosciation table:

It is the database that defines the different nodes- Host,CCM,and RTU's-on the

network.The database defines the names used for the different nodes and their hierarchi

assosiations with each other.

RTU Profile:

It is the database that defines the hardware configuration on the I/O board slot

assignments and the allocations of different point types with in the RTU.

Point database:

It is a large database that defines each I/O point in the S/3 system. The database

contained information concerning point location, point descriptor, point descriptor, point

type, display limits, engineering unit type, and so on.

Console database:

It is a database residing at the colour console that contains a library of graphics used for

the S/3 graphic displays.

PLC database:

It is an optional database used to support the foreign RTU interface. This database

defines the elements required to interface with a PLC or other intellgent device.

Historical trend list:

It is a list that defined the point marked for historical trending.

Current trend list:

It is a list of points that are marked for current trending.

Alarms management database:

It is a list of current alarm messages in the system.

APPLICATION OF MK 1 SYSTEM

(1) Word structure

(2) Out station address allocation

(3) Function address allocation

(4) RTU operation

(5) State monitor operation

(6) Analog monitor operation

(7) Totaliser operation

(8) RTU status monitoring

(9) Local RTU

WORDSTRUCTURE :

RTU s are arranged in a radial / Multidrop configuration. The communication is

used in half duplex mode .

The interrogation message has a fixed length of 5bytes , and the reply has a fixed

length of 13 bytes.

OUTSTATION ADDRESS ALLOCATION

Out station addresses are set in the range 1 –255 by dual in line (DIL) switches

encoded in binary on the RTU basic tier motherboard.

Field RTUs are assigned addresses 001,002 ,………023.no RTU is assigned the

address ‘ 000 ‘ as it is mean for Broadcasting information from the MS to all the RTU s

simultaneously. When the network expand in future , the present SCADA system, the

new RTUs will be assigned addresses 024,025…

FUNCTION ADDRESS ALLOCATION :

Function address are allocated as shown bellow . Use of the function address

is described under the individual heading in the reminder of this section .

32 -- 47 Analog control select

48 -- 63 Pulse input, Totoliser

88 -- 95 Digital input state monitor

96 -- 159 Analog input analog monitor

160 -- 225 Master control test – 2, Check monitor

RTU OPERATION :

The center of RTU operation is the microprocessor which essentially acts as a

buffer between communication with the MS and control / monitoring of the plant .

The microprocessor maintains in its store a record of plant interface modules

fitted and in the case of monitor modules it maintains a record of the corresponding plant

data. The plant data record is regularly updated, although the actual stimulus for updating

a varies between systems , and between different types of plant input,.

Communication between the microprocessor and the plant interface cards is

through a common input – output highway to which all the plant interface cards are

connected.

STATE MONITOR OPERATION :

The allocation to function address is arranged to allow monitoring of upto 512

single bit inputs.

After intialization the RTU microprocessor uses the input – output highway to

monitor the state of all state monitor inputs, and creates a stored record of the initial

status . The microprocessor continues to monitor the inputs on a regular basis ,

nominally every 20 msec and compares the monitor state with the stored state when a

discrepancy is found the micro processor record is updated, and a change of state marker

is set against the changed bit. There after no change to the record of that bit is made untill

the change of state marker is cleared.The marker is cleared after interrogation of the

RTU on the appropriate state monitor function addresss. Associated with the state

monitors are two change of state status bits. The first is set if any changed of state marker

set in the function range 88 – 91 and is monitor inbit 4 of the statua byte of every

message from RTU to MS.

The second operates similarly for function addresses 92 –95 and is monitored in

bit 5. the bits are clear if there are no changes outstandig beyond those indicated in the

reply to the current interrogation.

The MS recover the status of the state monitors from the stored record

interrogation mode. The information bytes of the interogation message comprise a state

monitor function address which define a group of 64 bits, follows by zero data byte. The

information bytes of the reply message comprise a repeat of the received state moniter

function followed by 8 data bytes contaning the state monitor data.

ANALOG MONITOR OPERATION:

The allocation of funtion adderss is arranged to allow monitoring of up to 256

analog values . Each analog value is reprasented as 11 bits pulse signal . Thus two bytes

are required for each analog value . The first byte contains the sign byte in the most

significant position,0 representing positive value and most 7bits in the remaining

positions. The second byte contains the remining 4 bits in the most significant

positions,followed by four zero bits .

The analog instrumentation is permanently powered and all inputs are

permanently on – scan . After initialization the RTU uses the input – output high way and

ADC to build a stored record of the value of all the inputs. There after the stored record is

up dated at two second intervals , or continously if the time taken to scan all analog value

exceeds to seconds .

If the time taken to scan all analog exceeds 4sec the analog scaning system is

reinitialized and RTU soft ware status of the bite is monitored in bit 4 of the check

monitor RTU status byte described latter, and is monitored by the MS . the bite is cleard

again when a successful analog scan achieved .

The MS may recover the value of the analog monitors from the stored record

using interrogation mode . the information bytes of the interrogation message comprise

an analog monitor function adderss , with defines a group of 4 analog values , followed

by 0 data byte . the information bytes by the reply message comprise a repeate of the

received analoge monitor,followed by 8 data bytes formed as 4paires each with 1 analog

value .

TOTALISER OPERATION :

The allocation of function addresses is arranged to allow monitoring of up to 16

inputs.

Each totaliser input pulse stream is accumulated in a 6 decade hardware counter

on the paint interface totaliser card . On initialization the RTU uses the RTU input –

output high way to reset total to zero. There after the Microprocessor monitors the

hardware toyals on a regular basis.

The RTU Microprocessor maintains two records of each totaliser value. One is

the 6 decade software record of the accumulated total. Designated the basic total and this

is regularly updated at all times .The other designated the message total is normally a

copy of the first and is used to generate the reply message data to MS interogations. The

MS can freeze the message total, but not the basic total , of all totaliser at any time by

using the totaliser freeze control function address.

The MS may recover each total from the stored record using interrogation mode .

The information bytes of the interrogation message comprise a totaliser function address

followed by a zero data byte. The informaton bytes of the reply are shown under reply for

totaliser.

RTU STATUS MONITORING :

The RTU status is monitored in two ways . The first is the RTU status byte

included in every message from RTU to MS . The second in the special check monitor

function.

LOCAL RTU :

3nos. local RTU s are employed to drive the wall mimic lamps using stae

control outputs and digital panel meters ( DPMS ) using analog control outputs. The

facilities of the local RTU are similar to other RTU s expect that Each local

RTU allows for up to 320 state control outputs.So analog outputs and no plant

monitoring . To achieve this the local RTU has different function address set . The

allocation of function addresses is given at figure . Unlike the normal RTU s , more

that one control can be active at any give time.

DATA ACQUISITION AND CONTROL:

The communication handler at central station of SCC shall perform the task of

transmitting the collecting information to and from each RS,determining the information

as data or control and respond to all requests of central processing unit(CPU) according

to established procedures.This shall scan the remote station in periodic and /or event

driven mode on a programmed poll basis to collect up-to-date status of various

parameters as well as transmission of control commands to the destined stations under

directives of the CPU . Any command signal issued from the destines stations under

directives of the CPU. Any command signal issued form the supervisory control or

remotely located VDU at MRS shall be routed through this communication handler to the

relevant RS / RS s over the same and /or separate cable communication line based on the

application programs to handle a specified volume of tele-- control signals.

The intelligent remote stations (RS) acting as slave to the central station shall

continuously scan various parameters and keep the updated information ready for further

transmission to the central station .The exchange of information between the central

station and RS shall be achieved on standard protocol consisting of 'interrogation ' from

the central station followed by 'reply' from the RS .The entire communication shall be

carried out under the control of central station software .The normal polling sequence will

allow the RS s to return date with transmission priorities for different types of

information.

The text structures for data transmission shall preferably be as recommended by

CITT. Generating suitable check codes and performing necessary validity checks shall

provide transmission protocol handling and safeguarding the integrity of data against

communication noise. All information shall be protected against transmission error to

detect and/or correct single and multiple errors including inverse code check for

protection of command transmission during tele --control functions.

INFORMATION PROCESSING:

The system shall handle a variety of information for the utility and power

distribution networks for function outlined in item 6.2 and 6.3.the network information

comprises the following categories :

Indication derived mainly from the ON/OFF contact status .

Measurands being a digital representation of any analog signal.

Pulse relating to counting of the rate of certain physical value.

A real time data base forming a part of system software shall handle all the

above type of Input/Output data to have continuous telemeter,telesignaling,telecontrol

and computation functions as required for the plant.This will cater for data updating,

request/receive of data from RSs,signal definition,scaling of data,accessing and

processing of data.

COMMUNICATION WITH EXTERNAL COMPUTER SYSTEM:

The supervisory control system computer shall have communication link with the

central computer system as well as power plant computer system independently for data

exchange. The supervisory system computer shall be provided with data transmission

adaptor along with necessary software for handling communication protocol so that the

external computer systems could be linked through MODEM for establishment of

communication as required.

CONCLUSIONSupervisory control and data acquisition system is a versatile network of

intelligent sub systems, which has brought revolution in the field of monitoring and

controlling systems. Earlier due to lack of sophisticated equipment it was very difficult

to predict whether the channel corrupted the data coming to the monitoring station or it is

the date pertaining to a functional error in a particular department. Further it was a very

time consuming process to undo the effect causing the problem (only after making sure

the data received is correct). In the mean time a lot of energy is waste and sometimes

even unacceptable hazards also used to take place. Also there was no privilege to track

the position that is responsible for the error.

The supervisory control and data acquisition system over comes all the above

bottlenecks. It has host computer in the master station to store the data for a long period

of time so that it can be sued to take strategic decisions sat the time of crisis.

The proposed SCADA System for Vizag Steel Plant shall acquire various

electrical and utility parameters for effective monitoring and control operations. The

various parameters acquired shall be such as electric power, voltages, currents, etc.

under electrical monitoring and parameters such as flows, temperatures pressures, etc.

under utility monitoring.

These parameters are logged into the system using a suitable database

management system. The data is processed and presented in the plant to the concerned

officials and operators using user-friendly graphical interfaces.