Index 1. Introduction to VSP a. Introduction to communication b. Role of communication c. Types of communication systems d. Objective 2. Coke ovens & vhf system a. Block diagram 3. Construction a. Description in detail Receiver Transmitter Microprocessor control Synthesizer Phase locked loop Phase comparator Voltage controlled oscillator EPROM Signaling Power supply and Reset Switched mode power supply Control and Display
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Transcript
Index
1. Introduction to VSP
a. Introduction to communication
b. Role of communication
c. Types of communication systems
d. Objective
2. Coke ovens & vhf system
a. Block diagram
3. Construction
a. Description in detail
Receiver
Transmitter
Microprocessor control
Synthesizer
Phase locked loop
Phase comparator
Voltage controlled oscillator
EPROM
Signaling
Power supply and Reset
Switched mode power supply
Control and Display
4.Technical specifications
5. Additional features of the base station
6. Programming of the base station
7. Trouble shooting of the base station
8. Suggested applications of the vhf systems
9. Conclusion
1. Introduction to VSP:
Visakhapatnam steel plant is the only shore based integrated steel
plant in our country. Smt.Indira Gandhi laid the foundation stone fulfilling the long
cherished dream of the people of Andhra Pradesh.
Due to the past experience it was realized that in order to be viable,
this plant need to operate at high levels of efficiency comparable with international
standards. It is also necessary that the plant reach its rated capacities at the shortest
possible time. For achieving this it is essential that this plant be characterized as
one having
a) Minimum manpower
b) Better discipline
c) Good team work.
The blue print of Visakhapatnam Steel Plant described the plant as the most
modern Steel plant employing new technologies - very best in the industry with
latest instrumentation and introduction of computerization on large scale.
Visakhapatnam steel plant is located 15 Kms to the South West of the
Visakhapatnam Port. It lies between the Northern boundary of the National
Highway No. 5 from Madras to Calcutta and 7 Kms to the South West of Howrah
Madras railway line.
b) MAJOR PRODUCTION FACILITIES:
VSP has the following major production facilities:
4 coke oven batteries of 67 ovens each and 41.7 cu mt Volume
2 Sinter machines of 312 sq mt area
2 Blast furnaces of 3200 cu mt useful volume
SMS with 3 LD converters of 150 ton capacity and 6 nos of 4 strand
continuous bloom casters
Light and medium merchant mill of 7,10,000 tons per year capacity
Wire rod mill of 8,50,000 tons per year capacity
Medium Merchant & Structural mill of 8,50,000 tons per year capacity
i) Coke Oven and Coke Chemicals Plants:
Coke oven plant consists of three coke oven batteries of 67 ovens each
with useful coke chamber volume of 41.6 cubic meter. Each battery is of 7 meters
height. It produces coke in the sizes of 25 to 70 mm, which meet the coke
requirement of the Blast furnaces. The annual capacity of the three batteries is
2.261 mt. During production operation the CO gas (carbon monoxide) generated is
used in the Coke chemical plants to extract different byproducts like Benzol,
Ammonium Sulphate, Tar products etc. After extracting all the valuable products
the remaining gas is used as an energy source.
ii) Sinter Plant:
There are two sinter machines each of 312-sqmt-grate area. Here iron ore
fines, coke breeze, lime stone, dolomite are mixed together to from the
agglomerated mass, called gross sinter which is used in Blast Furnaces as the
primary input. The annual production capacity is 5.256 mt.
iii) Blast Furnace (BF):
There are two Blast Furnaces named "GODAVARI" and "KRISHNA", each
of 3200 cubic meter useful volumes. Here hot metal is produced from the raw
materials like iron ore (Lump), sinter, coke and limestone etc. The annual capacity
of this facility is 3.4 mt. From molten hot metal pig iron / steel is produced.
iv) Steel melting shop (SMS):
There are three nos. of LD converters each of 133 cubic meters with a
capacity to produce 3 mt of liquid steel. The production capacity of a plant is its
capacity to produce liquid steel. VSP is a 3-mt plant. SMS also has six number of
four strand continuous casting machines to produce blooms. 2.82 mt of blooms can
be cast annually. In this shop hot metal from BF is received in the mixer, kept for
temporary storage and transferred to converter where charging takes place in
presence of 99.5% pure oxygen. After Argon rinsing the molten steel is moved
from here to the six strand continuous casting machines. Blooms are formed which
form the input material for the mills. Blooms are also taken as input to small steel
making industries.
V) Rolling Mills (RM):
There are three rolling mills in VSP
Light & Medium merchant mills : It includes the billet mill and bar mill. It has a
two-strand rolling mill. It produces billets, bars and structures. The annual
capacity is 1.857 mts of billets and 7.1 mt of bars & structures.
Wire Rod mill : It is a high-speed four strand continuous mill. The mill is
designed to produce wire rods in plain rounds and ribbed bars (5.5 to 12.7 mm
diameter). The annual capacity of wire rods production is 0.8 mt.
Medium and Merchant mill : This mill produce squares 12 to 65mm, flats 30 to
150mm, channels and angles etc. This mill has an annual capacity of 0.85 mt of
bars and structures.
1) INTRODUCTION TO COMMUNICATION SYSTEMS:
Communication System refers to sending, receiving and processing of
information from one point to another point. A modern communication system is
first concerned with sorting, processing and storing of information before its
transmission .The processing involves conversion of voice signal into an electric
signal and then transmitted. The message need not be voice alone; it can be data,
image or a mixture of all the three forms of data.
The signal transformation process generally goes through the following steps.
The information signals are first compensated for frequency distortions.
The signals are then amplified so that they can be suitably modulated.
The modulated signal is boosted to sufficient levels to overcome the
effects of noise.
The signals are then passed onto an aerial system where these are
converted from electrical energy to electromagnetic energy.
At the receiving end the receiving system should be capable of recognizing
the signal and then capable of compensating the signal loss and provide a faithful
reproduction of the transmitted information at useful levels.
The receiving end consists of an aerial to receive the electromagnetic
energy and convert it into electrical signals.
Sensitive circuitry to recognize the signal, demodulate the signal and
compensate for distortions introduced by the channel.
Amplify the signal to audible levels.
In this modern age of industrialization and automation, telecommunication
play a very vital role in achieving the assigned targets and accomplishing the
desired performance in any organization, this is more so in case of an integrated
steel plant where the effective, efficient and reliable flow of information and
communication between different production shops, maintenance and service
departments.
Modulation:
Modulation is defined as the process by which some characteristics, usually
amplitude, frequency or phase, of a sinusoidal voltage is varied in accordance with
the instantaneous value of some other voltage called the modulating voltage.
The term carrier is applied to the voltage whose characteristic is varied and
the term modulating voltage is used for the voltage in accordance with which the
variation is made. Usually the modulation frequency is considerably lower than the
carrier frequency.
Need for Modulation:
There are two alternatives to the use of a modulated carrier for the
transmission of messages over long distance in the radio channel. Several
difficulties are involved in the propagation of electromagnetic waves at audio
frequencies below 20 Kilohertz. For efficient radiation and reception the
transmitting and receiving antennas would have to have heights comparable to a
quarter wavelength of the frequency used. All sound is concentrated within the
range from 20Hz to 20 KHz, so that all signals from the different sources would be
hopelessly and inseparably mixed up. In any city, the broadcasting stations alone
would completely blanket the “air”, and yet they represent a very small proportion
of the total number of transmitters in use.
In order to separate the various signals, it is necessary to convert them all the
different portions of the electromagnetic spectrum. Each must be given its own
frequency location. This overcomes the difficulties of poor radiation at low
frequencies and reduces interference. Once signals have been translated, a tuned
circuit is employed in the front end of the receiver to make sure that the desired
section of the spectrum is admitted and all the unwanted ones are rejected. The
tuning of such a circuit is normally made variable so that the receiver can select
any desired transmission within a predetermined range, such as the VHF broad cost
band used for frequency modulation. Separation of signals has removed many
difficulties in the absence of modulation. An unmodulated carrier has constant
maximum amplitude, a constant frequency and a constant phase relationship. In a
continuous modulation system, one of the parameters of the carrier is caused to
vary. Thus at any instant its deviation from the unmodulated value is proportional
to the instantaneous value of the modulating voltage, and the rate at which this
deviation takes place is equal to the modulating frequency.
Levels of modulation: (figures –td 60, 61)
In low-level modulation little power is associated with either the signal or
the carrier. The output of the modulator is at a lower level. A series of linear
power amplifiers are then used to boost the signal level to higher levels.
In high-level modulation the carrier and information signals are amplified to
sufficiently higher levels before modulation. This requires amplifiers, which are
linear over a wide range of frequencies.
Modulation techniques:
Among the available types of modulation techniques, Amplitude
modulation, Phase modulation and Frequency modulation are most popular.
Modulation is the process of converting a signal from its primary form to a form,
which is most suitable for transmission. This is realized by using a high frequency
signal as ‘carrier’ and varying one of its parameters like amplitude or phase or
frequency as a linear function of the instantaneous value of the modulating signal
the ‘message’. At the receiver end the reverse modulation ‘de-modulation
techniques are employed to extract the signal ‘message’ .
In all these three techniques the frequency component of the modulating
signal would occupy a different frequency component of the frequency spectrum in
the modulated form. All the above are linear modulation techniques.
Amplitude Modulation:
In amplitude modulation, the amplitude of the carrier voltage is varied in
accordance with the instantaneous value of the modulating voltage.
The unique feature of this type of modulation is that the envelope of the
modulated carrier signal has the same shape as that of the modulating signal.
Amplitude modulation requires that
a) Carrier frequency is very much higher than that of the modulating
signal
b) The amplitude of the modulating signal is less than that of the carrier
In case the above two conditions are not met, it would result in distortion of
the received signal. The detection of signal from AM signals uses two types of
methods, they are coherent / synchronous detection, de-multiplier techniques or
diode / envelope detection. Amplitude modulation results in generation of USB
and LSB (the upper and lower side bands).
Frequency Modulation:
Frequency modulation consists in varying the frequency of the carrier
voltage in accordance with the instantaneous value of the modulating voltage
In cases where noise levels are inherent with signal in relatively large amplitudes
FM is used. FM is a non-linear or exponential technique and helps to discriminate
wanted and unwanted components of the signal in the post modulated spectrum.
Due to its non-linear nature the signals are required to be processed for
compensation.
Phase Modulation:
Phase modulation consists in varying the phase angle of the carrier voltage
in accordance with the instantaneous value of the modulating voltage.
Apart from the above pulse modulation is becoming popular due to its high signal
to noise ratio. The parameters of amplitude and frequency are varied and thus pulse
amplitude modulation, pulse width modulation, time division multiplexing,
frequency shift keying etc have come into existence.
Pre-emphasis and De-emphasis:
The boosting of the higher modulating frequencies, in accordance with a
prearranged curve, is termed Pre-emphasis and the compensation at the receiver is
called De-emphasis. Take two modulating signals having the same initial
amplitude, and one of them is pre-emphasized to twice this amplitude, other is
unaffected (being at lower freq). The receiver has to de-emphasize the first signal
by a factor of 2, to ensure that both signals have the same amplitude in the O/p of
the receiver. When this signal is de-emphasized, any noise sideband voltages are
de-emphasized with it, and therefore have lower amplitude than they would have
had without emphasis. There effect on the O/p is reduced. The higher modulating
frequencies must not be over emphasized. The curves of figure show that a 15KHz
signal is Pre-emphasized by about 17dB. When such boosting is applied the
resulting signal cannot over-modulate the carrier by exceeding the 75KHz
deviation, or distortion will be introduced. It is difficult to introduce Pre-emphasis
and de-emphasis in existing AM services since extensive modifications would be
needed, particularly in view of the huge numbers of receivers in use.
Propagation of Electromagnetic waves:
In an earth environment, electromagnetic waves propagate in ways that
depends not only on their own properties but also on those of the environment
itself since the various methods of Propagation it depends largely on frequency, the
complete electromagnetic spectrum shown in figure.
There are five different types of wave propagation as given below. The most
important of these are the ground wave (surface wave), sky wave and space wave
propagation. The Earth, the atmosphere and the frequency of signal generally
govern the propagation.
The direct wave due to line of sight propagation between the radiator and
receiver.
The reflected wave arrival after reflection at an intermediate point on the
earth’s surface.
The surface wave produced by energy traveling close to the ground and
guided by it to follow the curvature of the earth, subject to laws of
diffraction.
Ionospheric wave (sky wave) leaving the transmitter aerial in an upward
direction and being bent by the conduction layers of the atmosphere to reach
earth.
Frequency and method of propagation:
< 500 KHz Surface wave
500 KHz to 1.5 MHz Surface wave for shorter distances and
Ionosphere wave for longer distances.
1.5 MHz to 30MHz Ionospheric wave
> 30 MHz Line of sight propagation
Propagation of Radio waves:
Surface Wave:
A ground wave travels along the surface of the Earth (Thus the ground wave
is required to be vertically polarized-vertical electric field). As the wave travels it
induces energy currents into the Earth and thus looses energy as it travels. Due to
dissipation of energy into the Earth the surface wave suffers attenuation, which is a
function of Earth’s conductivity. The loss is compensated by the downward flow of
energy from upper layers due to diffraction. The wave front gradually tilts as it
propagates and finally the wave dies. Thus range depends on the power and
frequency with which the initial wave is transmitted.
Space Wave:
For frequencies in the range of 30 MHz ground waves get attenuated within
a few hundred feet distance. These waves do not get reflected even by the
Ionosphere. Hence the only way of transmission is by line of sight. The limitation
is the curvature of the Earth. Space wave comprises of two types. The direct wave
and the ground reflected wave. The problem with the later type is unless the
resultant of the direct wave and reflected wave is significant at the receiving end
the signal strength may not be of any use. The problem of shadow zone is
associated with space, antenna height and LOS reception.
Ionospheric Wave:
Due to ultra violet radiation the molecules in the atmosphere get ionized.
Since the density of molecules is high and radiation is low at lower heights the
ionization effect is not felt. But at distances of 50 Kms to 500 Kms above the
Earth’s surface this is considerable. This area of ionization is called ionosphere.
For waves of frequencies below 100 KHz the change in electron density
occurs over a distance relatively smaller than wavelength and the ionosphere will
act as a perfect reflector. Long distance propagation is possible due to multiple
reflections between Earth and Ionosphere. In case of waves of higher frequencies
the Ionosphere acts a bad conductor and as a refractive medium due to which the
wave gets refracted as it passes through the layers and eventually gets bent towards
the Earth. For certain angles of incidence the wage will not get reflected back but
passes through the layers. So a critical angle of incidence comes into effect. When
an electromagnetic wave gets trapped in the Earth’s atmosphere it tends travel
fairly large distances along the surface of the Earth and this phenomenon is termed
as duct propagation.
Maximum usable frequency:
This is the maximum frequency that can be reflected back for a given
distance of transmission using reflections from the atmosphere.
Skip Distance:
The minimum distance over the transmitted after going into the atmosphere
touches the Earth for the first time. Reception within the skip distance is not
possible while using sky waves.
Impedance matching:
The iron-cored transformer is used for matching impedances at the lower
frequencies. At higher frequencies air core transformers are used for impedance
matching. Another method used for impedance matching is the usage of four
terminal networks. The four terminal networks is composed of reactive elements
to avoid dissipation of the RF power and also it can be used over a narrow band of
frequencies thus resulting in increased efficiency of transmitted power. The
network is designed on an image basis to match the resistance part of the load.
Wave Guides:
Up to 1 GHz, the attenuation in polyethelene cables is mainly due to the
conductor material (i.e. copper losses). The attenuation varies as the square root of
the frequency. Beyond 1 Ghz, the dielectric losses also become appreciable and
vary as the frequency of operation at 10 Ghz. At still higher frequencies the
current tends to travel at the outer surface and loss is due to the core material.
Removing the core material can increase the efficiency of transmission. This gives
rise to the hallow pipe or the wave-guide.
Antennas:
An antenna is a structure – generally metallic and sometimes very complex –
designed to provide an efficient coupling between space and the output of a
transmitter or the input to a receiver. Like a transmission line, an antenna is a
device with distributed constants, so that current, voltage and impedance all vary
from point to the next one along it.
The antenna offered with the fixed station Transceiver is of ground plane type
having omni directional radiation pattern.
Antenna Gain and Effective Radiated Power:
Certain types antennas focus their radiation pattern in a specific direction, as
compared to an omni directional antenna.
Directive Gain:
Directive gain is defined as the ratio of the power density in a particular
direction of one antenna to the power density that would be radiated by an omni
directional antenna (isotropic antenna). The power density of both types of
antenna is measured at the same distance, and a comparative ratio is established.
1. The longer the antenna, the higher the directive gain.
2. Non-resonant antennas have higher directive gains than resonant antennas of
equal lengths.
Directivity and power gain:
The maximum directive gain is defined as the gain in the direction of one of
the major lobes of the radiation pattern. The maximum directive gain is also
referred as Directivity.
Another form of gain used in connection with antenna is power gain. Power
gain is a comparison of the output power of an antenna in a certain direction to that
of an isotropic antenna. The gain of an antenna is a power ratio comparison
between an omni directional & unidirectional radiator.
This ratio can be expressed as
A (dB) = 10log10 (p2/p1)
A (dB) = antenna gain in decibels
P1 = Power of unidirectional antenna
P2 = Power of reference antenna.
Field Intensity:
The field strength (field intensity) of an antenna’s radiation, at a given point
in space, is equal to the amount of voltage induced in a wire antenna 1m long,
located at that given point.
The field strength, or the induced voltage, is affected by a number of
conditions such as the time of day, atmospheric condition & distance.
The voltages induced in a receiving antenna are very small, generally in the
microvolt range. Field strength measurements are thus given in microvolt per
meter.
Antenna Resistance:
Radiation resistance is a hypothetical value, which, it replaced by an
equivalent resistor, would dissipate exactly the same amount of power that the
antenna would radiate.
Radiation Resistance:
Radiation resistance is the ratio of the power radiated by antenna to the
square of the current at the feed point.( P= I*I*R)ISQUARER
Bandwidth, Beam width, & Polarization:
Bandwidth, beam width & polarization are three important terms dealing
respectively with the operating frequency range of an antenna, the degree of
concentration of its radiation, and the space orientation of the radiated waves.
Bandwidth:
The term bandwidth refers to the range of frequencies over which the
antenna radiates effectively i.e. the antenna will perform satisfactorily through out
this range of frequencies.
Beam width:
The beam width of an antenna is the angular separation between the two half
-power points on the power density radiation pattern.
Polarization:
Polarization of an antenna refers to the direction in space of the E field
(electric vector) pattern of the electromagnetic wave radiated from an antenna.
Grounded Antennas:
If an antenna is close to the ground, the earth acts as a mirror and it becomes
a part of the radiating system. The ungrounded antenna with its image forms a
dipole array, but the bottom of the grounded antenna is joined to the top of the
image. The system acts as the antenna of double size.
The Marconi antenna has one important advantage over the ungrounded, or
Hertz, antenna. To produce any given radiation pattern it need be only half as
high. On the other hand since the ground here plays such an important role in
producing the required characteristics, the ground conductivity must be good.
Where it is too low, an artificial ground is used. The radiation pattern of Marconi
antenna depends on its height.
Ungrounded Antenna:
An image antenna is visualized to exist below the earth surface and is a true
mirror image of the actual antenna. Once the image has been established, the
resulting radiation may be considered as having come from the antenna and its
image, rather than from an antenna situated above a reflecting surface.
Horn Antenna:
There are two types of horn antennas present. They are basic horn and
special horn. When a wave-guide is terminated by a horn, the abrupt discontinuity
that existed is replaced by a gradual transformation.
UHF and Microwave Antennas:
Transmitting and receiving antenna designed for the UHF (0.3 – 3GHz) and
microwave (1-100GHz) regions tend to be directive.
Antennas with Parabolic Reflectors:
A practical reflector employing the properties of the parabola will be a three
dimensional surface, obtained by revolving the parabola about the axis. The
resulting geometric surface is the paraboloid, often called a parabolic reflector or
microwave dish.
2) ROLE OF COMMUNICATION (at VSP)
The communication plays an important role in the following things:
To transfer information (voice, video, data) from one place to another
place efficiently.
To avoid the delay in production.
To avoid time delay in communication.
For instantaneous transfer of information.
To get proper feedback.
For the effective coordination among various departments or sections.
3) TYPES OF COMMUNICATION :
Different types of communication systems are being used to meet the
internal and external communication needs. These are broadly classified as follow:
General-purpose communication systems.
Process communication systems.
Monitoring and signaling systems
It is obvious from the classification that every type of communication
system cannot be used in every type of environment. Communication systems are
chosen in each shop floor depending on the ambient noise, communication needs
etc.
A. 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 town ship.
2500 lines electronic exchange of BSNL.
B. Process communication systems.
To facilitate coordination among operation & management activities of
production, maintenance and service departments, the following process
communication systems are provided:
Despatcher communication systems.
Loudspeaker intercom systems.
Loudspeaker broadcasting systems.
Loudspeaker conference communication systems.
Industrial public address system.
Hot line communication systems.
VHF communication systems.
C. Monitoring and signaling systems.
To facilitate and operate production activities remotely the following
Monitoring and signaling systems are provided:
Closed Circuit Television Systems (CCTV).
Central fire alarm signaling system.
Supervisory Control and Data Acquisition Systems (SCADA).
Shift change Announcement Siren system.
Briefly,
1. For the purpose of Intra shop communication needs ELECTRONIC
“Despatcher Communication Systems” are used.
2. In order to communicate in noisy environment and also to communicate
between any two stations having interconnectivity on selection basis, we use
“Loud Speaker Intercom Systems”.
3. For communicating general information to personnel on the shop floor
“Loud speaker broadcasting systems”. Are being used
4. For locating individuals and then communicating personally in noisy
environment, we prefer “Loud speaker conference communication systems”.
5. For the purpose of Communication by means of announcement and also
through hand sets in private mode in extremely noisy environments like that of
power plants, “Industrial public address and conference communication
system” are used.
6.Specified locations are connected permanently so that whenever one
subscriber lifts his telephone the other will immediately get a ring and
communication can be had with out any loss of time using “Hotline
communication systems”.
7. In order to supervise critical operating areas of major production units from
their concerned control pulpits, we prefer “ Closed Circuit Television Systems”.
8. For the simultaneous actuation of sirens to alert personnel of the affected
plant zones, we prefer “Central fire alarm signaling system”.
9.For closely monitoring the generation and distribution of energy
rationalization of the distribution based on the available energy, we prefer “
Supervisory Control and Data Acquisition System”.
10. For ensuring uniform and accurate shift timings throughout the plant, we
prefer “Shift change Announcement Siren System”.
11. For the purpose of talking to individuals while working at site or on move “
VHF Communication Systems” are used
1. Hand held VHF Walkie Talkies:
This system comprises of hand-held VHF mobiles (including a battery pack)
working on the respective battery frequency. Usually these walkie-talkies are in
the hands of the shift in-charges and some key operators, who have to be moving
regularly.
2. Mobile phones :
A VHF Base Station means a VHF Transceiver fixed on mobile equipment
like jeeps of CISF and fire fighting fleet etc working on the vehicles of the battery.
3. Base stations:
A VHF Base Station means a VHF Transceiver fixed in a metallic / wooden
enclosure along with an ‘AC’ to ‘DC’ power supply equipment and external
sockets for fist microphone and antenna connections.
The Base Station is to be fed with 230V 1-, AC power supply. This AC
will be converted into a DC voltage of 13.2v by the power supply cabinet inside
the base station of PRM 8020
1d.OBJECTIVE
To Study VHF Communication systems employed in Coke Ovens Batteries
of C&CCD department in VSP. The study starts with comparison of various types
of communication systems that can be used in battery applications. After this the
superior system i.e. VHF Communication is explained in detail. Of the various
models employed, the VHF Base Station with PRM 8020 Transceiver of Simoco
Telecommunications make, is taken up in this project. This involves the study of
circuit diagrams, the hardware aspects, programming screens and trouble shooting
techniques.
2
2. Coke ovens and VHF system:
There are a total of 3 battery complexes presently operational in VSP. Each
complex consists of a battery of 67 ovens and one CDCP (Coke Dry Cooling
Plant). For each battery approximately 80 to 85 Coke pushing’s are done every
day. These operations are carried out by Ovens’ machines in each battery. The
following persons are involved in operation for each pushing and they are
provided with VHF system.
a. Operations Shift In-charge
b. Pusher Car Operator
c. DE (Door Extractor) Car Operator.
d. Charging Car Operator
e. Loco Operator
f. CDCP Lifter Operator
g. CDCP Control Room Operator.
Since four of the above locations are moving machines, a wired
communication is not practically viable. The best option for a maintainable
communication system is to go for a fixed type VHF system in all the seven (7)
locations. The single phase AC power required for the VHF system operation is
drawn from the machine supply.
A VHF System consisting of a seven VHF base Stations is required for
working in each battery. For this purpose, all the stations are to be tuned onto a
common frequency. In the case of battery I and II, some of the Ovens’ machines
are common for operations. It means that these common Ovens’ machines can be
utilized either in Battery I or in Battery II ovens. Therefore, dual frequency VHF
base stations are provided for Battery I and II machines.
For non-conflicting operations, the three Batteries (including the respective
CDCP) will work on three independent frequencies.
The three frequencies allotted to the Batteries are:
1. 149.450 MHz – Battery – I Frequency
2. 149.550 MHz – Battery – II Frequency
3. 149.650 MHz – Battery – III Frequency
S. No. LocationBattery
Number
Fixed /
Moving
Frequency
Value Type
1. Shift In-
charge Room
I Fixed 149.450Mh
z
Single
2. Pusher Car 1 I Moving 149.450Mh Single
z
3. Pusher Car 2 I or II Moving 149.450Mh
z
149.550Mh
z
Dual
4. Pusher Car 3 II Moving 149.550Mh
z
Single
5. Charging Car
1
I Moving 149.450Mh
z
Single
6. Charging Car
2
I or II Moving 149.450Mh
z
149.550Mh
z
Dual
7. Charging Car
3
I or II Moving 149.450Mh
z
149.550Mh
z
Dual
8. Charging Car
4
II Moving 149.550Mh
z
Single
9. DE Car 1 I Moving 149.450Mh
z
Single
10. DE Car 2 I or II Moving 149.450Mh
z
149.550Mh
z
Dual
11. DE Car 3 II Moving 149.550Mh Single
z
12. Loco 1 I Moving 149.450Mh
z
Single
13. Loco 2 I or II Moving 149.450Mh
z
149.550Mh
z
Dual
14. Loco 3 II Moving 149.550Mh
z
Single
15. CDCP-I
Control Room
I Fixed 149.450Mh
z
Single
16. CDCP-II
Control Room
II Fixed 149.550Mh
z
Single
17. Lifter Cabin –
1 (CDCP-1)
I Fixed 149.450Mh
z
Single
18. Lifter Cabin –
2 (CDCP-1)
I Fixed 149.450Mh
z
Single
19. Lifter Cabin –
3 (CDCP-1)
I Fixed 149.450Mh
z
Single
20. Lifter Cabin –
4 (CDCP-1)
I Fixed 149.550Mh
z
Single
21. Lifter Cabin –
5 (CDCP-2)
II Fixed 149.550Mh
z
Single
22. Lifter Cabin –
6 (CDCP-2)
II Fixed 149.550Mh
z
Single
23. Lifter Cabin – II Fixed 149.550Mh Single
7 (CDCP-2) z
24. Lifter Cabin –
8 (CDCP-2)
II Fixed 149.550Mh
z
Single
25. Telecom Lab I, II and
III
Fixed 149.450Mh
z
149.550Mh
z
149.650Mh
z
Multi
26. Shift In-
charge Room
(Battery- 3)
III Fixed 149.650Mh
z
Single
27. Pusher Car 4 III Moving 149.650Mh
z
Single
28. Pusher Car 5 III Moving 149.650Mh
z
Single
29. Charging Car
5
III Moving 149.650Mh
z
Single
30. Changing Car
6
III Moving 149.650Mh
z
Single
31. DE Car 4 III Moving 149.650Mh
z
Single
32. DE Car 5 III Moving 149.650Mh
z
Single
33. Loco 4 III Moving 149.650Mh
z
Single
34. Loco 5 III Moving 149.650Mh
z
Single
35. CDCP III
Control Room
III Fixed 149.650Mh
z
Single
36. Lift Cabin 9
(CDCP III)
III Fixed 149.650Mh
z
Single
37. Lift Cabin 10
(CDCP III)
III Fixed 149.650Mh
z
Single
38. Lift Cabin 11
(CDCP III)
III Fixed 149.650Mh
z
Single
39. Lift Cabin 12
(CDCP III)
III Fixed 149.650Mh
z
Single
PRM 8020 General Information:
The PRM 8020 series is a mobile radio transceiver unit manufactured by
M/s Simoco Telecommunications Limited. These are under-dash mounted local
controlled simplex radios for vehicular applications. The transceiver utilizes
microcomputer to control a frequency synthesizer and also to perform the analog
signaling. To suit the site requirements i.e. changing the frequency, band, power
and other features is called customization. Customization of the microcomputer
control is done via an EEPROM. This programming of the EEPROM is done
through a field-programming unit (FPU). The FPU consists of the system software
required for operation of PRM 8020, which in turn is loaded on a personal
computer. For customization, the transceiver is connected through its microphone
socket to the external PC.
TYPICAL CONNECTION FOR PROGRAMMING A TRANSCEIVER:
PRM 8020 provides up to 64 channels & 8 additional buttons are provided
which can be programmed to accept the additional features. The front panel of the