FIELD OF THE INVENTION
This present subject matter relates to the development of the controller of Gravimetric feeder in
coal-based power plants and process plants. More particularly, the invention relates to a method
of implementation of the complete control system of Gravimetric feeder with a specialized
protocol. The present subject matter also relates to the method of storage and retrieval of control
parameters, time synchronization mechanisms using a microcontroller module, RTOS based tools,
smart HMI and required input/output modules in the control system of the Gravimetric feeder.
BACKGROUND
Coal is a natural resource and is used as fuel in thermal power plants for generation of power. It is
burnt to generate thermal energy in the form of steam in the boiler. The amount of fuel input to
boiler has to be measured and controlled as per the demand. In the power plant coal is fed through
feeders to the boiler at different levels known as coal elevations. The method involves feeding of
the raw coal into the pulverizer, where the coal is broken into smaller chunks followed by
measurement of the quantity of the coal.
The most cost-effective means of controlling the input is by measuring the coal mass through
feeders. The feeder which feeds coal to the boiler must deliver the coal mass at a rate proportional
to the load demand. This has to be done independent of the physical parameters of coal and by
means of it the total weight of the coal fed into the feeder can be computed.
The popular method of feeder control is by Gravimetric method and the total system is known as
Gravimetric feeder control. A gravimetric feeder controller consists of two main parts, viz;
mechanical and the electronics. Normally all gravimetric feeders convey the material on a belt
and measure the weight of the material on belt to determine the material fed in to the pulverizer.
The actual control is by mass flow rate determined by the product of belt speed and mass per unit
length.
IN233680 titled “An Apparatus for Control of Coal Feeding Device” discloses a raw coal feeding
device that can deliver coal in proportion to the fuel demand generated by means of combustion
control envisaged in the boiler. The innovative aspect of this invention is to integrate advanced
microprocessor / microcontroller based modules to execute the different functions, like, logical,
sequencing timing, counting, computation, closed loop control, data archiving and communication

related to control the coal feeding process. The application program is stored in the read-write part
of the memory of the microprocessor / microcontroller and the feeding device is operated in
accordance to it. The man-machine interface provides apt guidance to the operating personnel for
easy operation / calibration in a user-friendly manner. Accordingly, there is provided an improved
apparatus for on-line computation and control of a raw coal feeding device in a coal fired boiler
system, the system comprising a plurality of integrated control means including a combustion
control means; atleast one belt conveyor carrying coal regulated by a drive means having an AC-
induction motor and a clutch; and atleast one calibration probe, the apparatus comprising a remote
control panel; a local control panel mounted on the raw coal feeding device, and connected via
screened cable to the remote control panel; a man-machine interface operably connected being
mounted on the door of the remote control panel; and configured to remotely operate the raw coal
feeding device, wherein the combustion control means transmits a signal representative of the fuel
demand by the boiler system, the local control panel having atleast one signal conditioning module
for receiving the signals and transferring the conditioned signals to the remote control panel, and
wherein the remote control panel comprising a plurality of card racks having atleast one
microcontroller module operable to compute on-line data and control the drive means of the coal
feeding device so as to feed raw coal in registration with the fuel demand communicated by the
boiler system.
CN106276155B titled “A kind of Gravimetric Coal Feeders device and its calibration method”
discloses a kind of a weighing coal feeder device and a calibration method consisting of a pre-
feeding conveyor, a weighing conveyor, a weighing sensor, a speed sensor, a weighing controller,
a check weight, a lifter, and a shell. The pre-coal conveyor is arranged above the weighing
conveyor, and the shell above the pre-coal conveyor is provided with a feed hopper. The invention
further discloses that the weighing sensor supports the weighing conveyor, and the speed sensor.,
The weighing scale is installed on the rotating shaft of the weighing conveyor and is erected on
the pre-feeding conveyor, one end of the lifter is fixedly connected with the shell, and the other
end of the lifter is connected with the test weight, weighing sensor and the speed sensor. The
weighing scale frame is also connected to the weighing controller. The invention can perform
physical calibration of the weighing coal feeder in real time, which can not only improve the
measurement accuracy of the weighing coal feeder, but also does not influence the normal
operation of the weighing coal feeder.

CN202614361U titled “A material calibrating device of a weighing coal feeder” discloses a
material calibrating device of a weighing coal feeder and belongs to technical field of metering
equipment. The material calibrating device comprises a calibrating hopper, a weighing and
transporting machine, and a material taking device. Material is taken from a material feeding
hopper of the weighing coal feeder followed by its passage into the calibrating hopper body. The
calibrating hopper body fully filled with material is weighed and moved to the middle of the
weighing coal feeder by the weighing and transporting machine, and is connected with bottom
interface of the calibrating hopper. When calibration is needed, the turning plate handle of the
calibrating hopper is wrenched so that quantitative material in the calibrating hopper body
uniformly drops to be spread out on a belt with material in order to complete superposed
calibration. The material calibrating device has advantages of simple structure, low cost, fastness
and easiness, high stability, and calibration to multiple weighing coal feeders by one device.
CN204606972U titled “Gravimetric Coal Feeders” discloses the utility model providing a kind of
Gravimetric Coal Feeders relating to metering feeding device field. Gravimetric Coal Feeders
comprises housing, establish by motor-driven cylinder and belt conveyor in housing, be provided
with weighing carrier roller below belt conveyor, surface of shell is provided with the first through
hole and the second through hole, and weighing carrier roller two ends are provided with the first
pressure portion through the first through hole, the second through hole and the second pressure
portion; Gravimetric Coal Feeders also comprises the first support, the second support, the first
LOAD CELLS and the second LOAD CELLS, respectively. The first pressure portion is placed
above the first LOAD CELLS and is connected with the first LOAD CELLS, and similarly the
second pressure portion is placed above the second LOAD CELLS and is connected with the
second LOAD CELLS. The first support is placed on below the first weighing and sensing and is
connected with the first LOAD CELLS, and the second support is placed on below the second
weighing and sensing and is connected with the second LOAD CELLS. The invention also
discloses that the LOAD CELLS are arranged on outside and also accurate measurement of the
LOAD CELLS which is not easily smashed by the material of sideslip.
CN208747039U titled “Totally-enclosed Gravimetric Coal Feeders” discloses totally-enclosed
Gravimetric Coal Feeders that relate generally to feeder field. The invention includes shell, first
conveying device, second conveying device and a weighing operating control device. The first

conveying device, on the other hand, includes main variable-frequency motor, transmission shaft,
drive roll, driven roller, conveyer belt, carrying roller, bearing, and the drive roll. The passive
roller is installed on shell by bearing and the main variable-frequency motor drives drive roll
rotation by transmission shaft. As disclosed in the invention, the second conveying device includes
auxiliary variable-frequency motor, spiral handspike, rolling bearing and auxiliary variable-
frequency motor mounted on shell. Both the ends of the spiral handspike are connected by rolling
bearing with shell, the output end of auxiliary variable-frequency motor and the shaft end of spiral
handspike. The operating control device of weighing includes weighing sensor, velocity sensor,
conducting wire, controller and the frequency converter. The utility model has the beneficial
effects that its timely automated adjustment of coal-supplying amount of energy meets the normal
operation requirement of boiler, while leakage coal can also be cleared up.
It is evident that the measurement of the quantity of the coal fed into the Gravimetric feeder is
extremely important as it impacts the cost of the system. The prior arts discussed mainly
improvises on the structural aspects of the gravimetric coal feeders and discusses about the
presence of various structural components that can quantify the amount of coal being fed into the
feeder. One of the prior art discusses the methodology to customize the controller of the
gravimetric feeder using microprocessor and microcontroller modules. Though the technique
described in the prior art is automated to some extent, but needs further improvement such that the
events can be recorded for precise monitoring and also the parameters can be stored for future use.
The implementation of these features can make the controller much more user friendly and cost
effective in nature.
OBJECTS OF THE INVENTION
It is a principal object of the present invention is to develop a controller and associated
communication framework with the input/output modules.
It is another object of the present invention is to develop a controller and associated communication
framework with the input/output modules where the processor module communicates data with
the input/output modules using a specialized bus.

It is another object of the present invention is to develop a controller and associated communication
framework with the input/output modules where the specialized bus of the processor module
consists of address and data buses and various control signals.
It is yet another object of the present invention is to develop a controller and associated
communication framework with the input/output modules in which an NTP server is used to read
the precise time and record the events of the process for further display and analysis.
It is another object of the present invention is to develop application code of the controller in Real
Time Operating System (RTOS) environment.
It is another object of the present invention that the developed application code of the controller in
RTOS environment can be implemented for storage facility in order to store parameters and
process results in a removable storage (SD Card) for offline analysis and for replication of spare
modules.
It is another object of the present invention is that the stored parameter developed by means of the
application code of the controller in RTOS environment can be shared with operators to their
mobile phone by means of a GSM modem.
It is another object of the present invention that the customized controller with the application code
developed in the RTOS environment will be cost effective in nature.
It is another very important object of the invention is the implementation of a tool for configuration
of system parameters that will be simple and easy to operate and also improve the system
reliability.
These and the other objects and advantages of the present subject matter will be apparent to a
person skilled in the art after consideration of the following detailed description taking into
consideration with accompanied drawings in which preferred embodiments of the present subject
matter are illustrated.
SUMMARY OF THE INVENTION
A gravimetric feeder controller normally consists of two main parts, namely mechanical and the
electronics. Generally the weight of the material on the belt is measured before it is being fed to

the pulverizer. The actual control is by mass flow rate determined by the product of belt speed and
mass per unit length.
The two conventional principles of measurement used in gravimetric feeders are as follows:
1. Keeping the mass per unit length constant and varying the belt speed with the demand signal.
2. Measuring the instantaneous reading of mass per unit length and belt speed, multiplying the two
measured parameters, comparing the product with the demand signal followed by varying the belt
speed to remove errors, if any.
The electronic system uses second method of control presently. In this method, the weighing
components are mounted inside the feeder. As a result, the feeder body is simplified in nature
thereby making the system cost effective.
The gravimetric feeder weighing system consists of two load cells to measure the mass on belt.
Load cells measure the change in resistance in strain gauges to measure the force. It is important
to select the load cell closer to the weight of coal being measured on weigh span. An oversized
load cell will cause less accuracy in measurement. Another factor is that the coal density is not
constant. Hence the system should take care of wide range of densities and provide control
functions accordingly.
The control system of gravimetric feeder consists of two electronic assemblies. One mounted along
with the feeder and in the other a remote power panel located in the control room. The electronic
assembly mounted along the feeder will have signal conditioning modules for load cell and
tachometers, panel mounted rotary and push-button switches, lamp indicators for feeder status.
The remote power panel will also have all the necessary power circuits and controller.
The controller (101) used for Gravimetric feeder controller, is built around a 32-bitcortex m7
microcontroller module. A smart HMI (104) is provided that is connected to the controller using
an Ethernet interface and communicates using the Modbus protocol. The smart HMI (104) located
on the Remote panel door provides the means to communicate and receive information from the
processor, for parameter setting, mode selection etc. The application software in the controller is
developed in ‘C’ language in a Real time Operating System environment. All the control
parameters of the gravimetric feeder are fed in to the controller module (101) from the smart HMI

(104) and are stored in non-volatile memory. Apart from the smart HMI, the operating status of
the gravimetric feeder is also displayed by bright lit LEDs.
The microprocessor feeder electronics control system uses special circuits, software routines and
nonvolatile memories to store data, retrieve and program parameters. The processor / controller is
packaged in a control rack in which EMI / EMC tests have been conducted.
The feeder controller further consists of the following hardware packages:
• Power supply
• Processor module
• Input and output modules
• Keyboard along with display
• Motor speed control module comprise the control system of the gravimetric feeder.
The GFC system contains the 32- bit microcontroller, memory, digital circuits and a keyboard
display etc. All I/Os are optically isolated with respect to processor and its associated circuits.
Analog circuits used to amplify and convert the load cell outputs are located separately in the
feeder local panel.
The closed loop control of the gravimetric feeder is accomplished by reading the input data from
the input modules, processing the data, execution of control loops and sending the outputs via
output modules. The kind of distributed I/O module (102) architecture enables the system to be
scalable and also reduces the downtime of the system as failure of an I/O channel would require
replacement of a single module. However due to the various sources of EMI in an industrial control
setup, there is a need to devise mechanisms to ensure correctness of data while maintain the speed
of operation of the control loops. The present invention deals with the implementation of a
mechanism of hardware connections and software logics to ensure the above said purpose.
Gravimetric feeders are deployed in thermal power plants and process plants where there are many
independent control systems and distributed control systems interdependent with each other. A
fault in one system would lead to change/tripping/ malfunction in a related function. In such
condition, it would be required to precisely record the time at which each event has occurred w.r.t

a known time reference common to all these control systems. To achieve this purpose, an NTP
client has been implemented, which continuously reads data from a NTP server (105) and updates
the RTC of the controller with the latest time for event recording.
With the growing proliferation of smartphones and mobile devices, the present invention also
enables user to be able to monitor the system operation and receive critical alerts regarding the
system functioning while away from the system. The above system implements a GSM based
communication for sharing system parameters and events from the gravimetric feeder control
system and user mobile phone through SMS alerts.
There are multiple gravimetric feeders in a typical power plant. Only a fraction of the feeders are
in operation at any particular instance of time. It is a desirable to be able to replace a malfunctioning
controller with a working one. But normally, changing a processor would require re calibration of
the feeder which is a lengthy process. In order to avert this, the present system implements a
mechanism of incorporating a system by employing a removable storage from which data can be
removed from the existing mal-functioned processor and placed in the new processor. The present
system also implements a PC based configuration tool for storage and retrieval of parameters in a
PC to be flashed in to the controller at a later date.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the
present subject matter and are therefore not to be considered for limiting of its scope, for the
invention may admit to other equally effective embodiments. The detailed description is described
with reference to the accompanying figures. In the figures, a reference number identifies the figure
in which the reference number first appears. The same numbers are used throughout the figures to
reference like features and components. Some embodiments of system or methods or structure in
accordance with embodiments of the present subject matter are now described, by way of example,
and with reference to the accompanying figures, in which
Figure 1 illustrates the block diagram of complete control system (100) in accordance with the
embodiment of the present disclosure.
Figure 2 depicts the general arrangement of the I/O modules (102) with the processor module in
accordance of the embodiment of the present disclosure.

Figure 3 illustrates the connection and communication architecture of the control system (100) of
figure 1.
Figure 4 depicts the screenshot of Configuration tool for Viewing and editing all system
parameters at once of figure 1.
Figure 5 depicts the screenshot of Configuration tool for Viewing and editing individual system
parameter shown in figure 1.
The figures depict embodiments of the present subject matter for the purposes of illustration only.
A person skilled in the art will easily recognize from the following description that alternative
embodiments of the structures and methods illustrated herein may be employed without departing
from the principles of the disclosure described herein.
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT
INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
While the embodiments of the disclosure are subject to various modifications and alternative
forms, specific embodiment thereof have been shown by way of example in the figures and will
be described below. It should be understood, however, that it is not intended to limit the disclosure
to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications,
equivalents, and alternative falling within the scope of the disclosure.
The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are
intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises
a list of components does not include only those components but may include other components
not expressly listed or inherent to such system, or assembly, or device. In other words, one or more
elements in a system or device proceeded by “comprises… a” does not, without more constraints,
preclude the existence of other elements or additional elements in the system or device.
Fig 1 depicts the general block diagram of the system architecture of the gravimetric feeder control,
herein referred to as system (100), in accordance with the subject matter of the present disclosure.
In an embodiment a cortex m7 based controller module (101) forms the heart of the system (100),
to which a plurality of I/O modules (102) are connected for data acquisition and control. In an

embodiment, a smart HMI (104) is present for interaction with user and performing calibration of
the system. In an embodiment a NTP server (105) is present wherein the NTP (105) is used for
updating of time. The embodiment further discloses the presence of a GSM modem (106) for user
alerts and PC with VC# based software for configuration of system parameters
Fig 2 depicts the hardware connection diagram of the controller module (101) with the I/O rack
system. The I/O rack consists of a Bus termination module and a plurality of I/O modules (102)
namely, Analog Input, Analog Output, Digital Input, Digital Output and Pulse Input, respectively.
In an embodiment, the CPU module connects to the bus termination module using a 50-pin flat
ribbon cable (103). In an embodiment, the Bus termination module in-turn connects to the plurality
of I/O modules (102) using an I/O back plane.
Fig 3 illustrates the connection diagram and communication architecture of the control system. In
an embodiment, the communication between microcontroller CPU and the plurality of I/O modules
(102) starts by asserting the RESET and SYNC signals with a pulse duration of t1 msec one
followed by the other pulse with a gap of t2 msec. A heartbeat pulse is asserted by the CPU with
a cyclical duration of t3 msec and read by each I/O module of the plurality of I/O modules (102)
to verify the healthiness of the CPU module. The time duration of t1, t2 and t3 as discussed in an
embodiment is configurable in software. The WD Error line is asserted whenever an I/O module
of the plurality of I/O module detects a missing watchdog pulse.
It may be noted that the actual data communication between CPU and the plurality of I/O modules
(102) takes place using a plurality of 16 address lines, 16 data lines, Handshake out1 signal,
Handshake out2 signal and handshake in signal, respectively. In an embodiment, the data
communication occurs by means of the following steps.
a) CPU writes the command and address of the module on address bus. The information on these
lines will be maintained throughout the transaction between the CPU and IO rack. This information
is read by the plurality of the modules (102) in the IO rack.
b) The plurality of modules (102) in the IO rack read the information on the address bus and
compares the address portion with the locally set address. If the address is not matching, the
module ignores the information. If the address matches with any of the modules of the plurality of
module, then the module responds.

c) The module for which the address is matching (current module) checks its "hand shake out1"
signal where hand shake out 1 is a bi-directional line and is switched accordingly . If this line is
high that means some other module of the plurality of modules (102) with same address is sending
the response. Hence the current module of the plurality of modules (102) need not send the
response but should wait for the "hand shake out1” to become low. Once this line is low current
module of the plurality of modules shall raise "hand shake out1" to high and send the error code
corresponding to more than one module of the plurality of modules (102) with same address in its
response. If address is matching and "hand shake1" is low then the current module of the plurality
of modules (102) reads the data and acknowledge by making "hand shake out1" high.
d) The current module of the plurality of module (102) reads the data and makes "hand shake 2”
high and checks for the "hand shake in" to go low. If it is low makes the "hand shake 2" to low.
e) If the data read is "STX" then it continues to receive the information as explained for "STX" till
it receives "ETX".
f) The total information received will be checked for validation by verifying the check sum. The
current module of the plurality of modules (102) responds with data error code if check sum fails.
g) The current module of the plurality of modules (102) prepares a string with "STX" as first and
"ETX" as last information and starts its response for the received command.
h) The current module of the plurality of modules (102) raises the “hand shake 2” to high.
i) The current module of the plurality of the modules (102) will wait for "hand shake in" to become
high, and makes "hand shake 2" low once "hand shake in" is high.
j) The current module of the plurality of the modules (102) will wait for "hand shake in" to become
low.
k) The current module of the plurality of the modules (102) repeats the steps 8 to 11 till all the
information is transmitted.
l) The "hand shake out1" will be made low by the current module of the plurality of the modules
(102).

The various operations of methods described above may be performed by any suitable means
capable of performing the corresponding functions. The means may include various hardware
component(s) and/or module(s), including, but not limited to a circuit, an application specific
integrated circuit (ASIC), or processor. Generally, where there are operations illustrated in figures,
those operations may have corresponding counterpart means-plus-function components with
similar numbering.
The various illustrative logical blocks, modules, units and circuits described in connection with
the present disclosure may be implemented or performed with a general purpose processor, a
digital signal processor (DSP), an application specific integrated circuit (ASIC), a field
programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or
transistor logic, discrete hardware components, or any combination thereof designed to perform
the functions described herein. A general- purpose processor may be a microprocessor, but in the
alternative, the processor may be any commercially available processor, controller,
microcontroller, or state machine. A hardware processor may also be implemented as a
combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality
of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other
such configuration. If implemented in hardware, an example hardware configuration may comprise
a processing system in a physical or wireless node. Hardware units store technical instructions,
data or any combination thereof that, when executed by an apparatus such as a processor which
alone or in combination with other hardware components, cause the processing system to perform
various technical functions.
The present subject matter relates to the development of a customized controller enabled with
advanced level of communication features that can be used for coal feeders. The method and
system for quantifying the amount of coal being fed into the feeder.
It should be noted that the description and figures merely illustrate the principles of the present
subject matter. It should be appreciated by those skilled in the art that conception and specific
embodiment disclosed may be readily utilized as a basis for modifying or designing other
structures for carrying out the same purposes of the present subject matter. It should also be
appreciated by those skilled in the art that by devising various arrangements that, although not
explicitly described or shown herein, embody the principles of the present subject matter and are

included within its spirit and scope. Furthermore, all examples recited herein are principally
intended expressly to be for pedagogical purposes to aid the reader in understanding the principles
of the present subject matter and the concepts contributed by the inventor(s) to furthering the art
and are to be construed as being without limitation to such specifically recited examples and
conditions. The novel features which are believed to be characteristic of the present subject matter,
both as to its organization and method of operation, together with further objects and advantages
will be better understood from the following description when considered in connection with the
accompanying figures.
Although embodiments for the present subject matter have been described in language specific to
package features, it is to be understood that the present subject matter is not necessarily limited to
the specific features described. Rather, the specific features and methods are disclosed as
embodiments for the present subject matter. Numerous modifications and adaptations of the
system/device of the present invention will be apparent to those skilled in the art, and thus it is
intended by the appended claims to cover all such modifications and adaptations which fall within
the scope of the present subject matter.
It will be understood by those within the art that, in general, terms used herein, and especially in
the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms
(e.g., the term “including” should be interpreted as “including but not limited to,” the term
“having” should be interpreted as “having at least,” the term “includes” should be interpreted as
“includes but is not limited to,” etc.). It will be further understood by those within the art that if a
specific number of an introduced claim recitation is intended, such an intent will be explicitly
recited in the claim, and in the absence of such recitation no such intent is present. For example,
as an aid to understanding, the following appended claims may contain usage of the introductory
phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such
phrases should not be construed to imply that the introduction of a claim recitation by the indefinite
articles “a” or “an” limits any particular claim containing such introduced claim recitation to
inventions containing only one such recitation, even when the same claim includes the introductory
phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or
“an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true
for the use of definite articles used to introduce claim recitations. In addition, even if a specific

number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize
that such recitation should typically be interpreted to mean at least the recited number (e.g., the
bare recitation of “two recitations,” without other modifiers, typically means at least two
recitations, or two or more recitations). Furthermore, in those instances where a convention
analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended
in the sense one having skill in the art would understand the convention (e.g., “a system having at
least one of A, B, and C” would include but not be limited to systems that have A alone, B alone,
C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.).
In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in
general such a construction is intended in the sense one having skill in the art would understand
the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited
to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C
together, and/or A, B, and C together, etc.). It will be further understood by those within the art
that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether
in the description, claims, or drawings, should be understood to contemplate the possibilities of
including one of the terms, either of the terms, or both terms. For example, the phrase “A or B”
will be understood to include the possibilities of “A” or “B” or “A and B.”
It will be further appreciated that functions or structures of a plurality of components or steps may
be combined into a single component or step, or the functions or structures of one-step or
component may be split among plural steps or components. The present invention contemplates
all of these combinations. Unless stated otherwise, dimensions and geometries of the various
structures depicted herein are not intended to be restrictive of the invention, and other dimensions
or geometries are possible. In addition, while a feature of the present invention may have been
described in the context of only one of the illustrated embodiments, such feature may be combined
with one or more other features of other embodiments, for any given application. It will also be
appreciated from the above that the fabrication of the unique structures herein and the operation
thereof also constitute methods in accordance with the present invention. The present invention
also encompasses intermediate and end products resulting from the practice of the methods herein.
The use of “comprising” or “including” also contemplates embodiments that “consist essentially
of” or “consist of” the recited feature.

Although embodiments for the present subject matter have been described in language specific to
structural features, it is to be understood that the present subject matter is not necessarily limited
to the specific features described. Rather, the specific features and methods are disclosed as
embodiments for the present subject matter. Numerous modifications and adaptations of the
system/component of the present invention will be apparent to those skilled in the art, and thus it
is intended by the appended claims to cover all such modifications and adaptations which fall
within the scope of the present subject matter.

We Claim:
1. A system (100) for controlling coal feeders (108) in thermal power plants comprising:
a controller module (101) configured to receive a plurality of data and the control signals
by a plurality of input-output (I/O) modules (102), wherein communication between the
controller module (101) and the plurality of I/O modules (102) is established via a Flat
Ribbon Cable (FRC) (103);
a smart Human Machine Interface (HMI) (104) connected to the controller module (101)
in order to facilitate the interaction with a user and perform calibration of the system;
a Network Time Protocol (NTP) server (105) connected to the controller module (101) in
order to record the time of feeding of the coal into a coal feeder (108);
a modem for Global System for Mobile Communications (GSM) (106) connected to the
controller module (101) in order to alert the user about the various activities performed in
the coal feeder (108); and
a removable storage connected to the controller module (101) of the feeder in order to store
and retrieve the data exchanged while operating the feeder.
2. The system (100) as claimed in Claim 1 wherein the communication framework between
the controller module (101) and I/O modules (102) is via 50-pin FRC (Flat ribbon cable)
(103) in order to ensure no data losses and increased accuracy.
3. The system (100) as claimed in Claim 1 wherein the NTP server (105) connected to the
controller (101) records the events related to the process of coal feeding into the feeder
(108) for further display and analysis.
4. The system (100) as claimed in Claim 1 wherein the GSM modem (106) is used for sharing
the system parameters and events from the coal feeder control system to mobile phones
(109) of users by means of message notifications.
5. A method of communication framework between the controller (101) of a plurality of I/O
modules (102), the method comprising the steps of:
a) fetching the command and address of the module (102) on address bus wherein the
information on these lines will be maintained throughout the interaction between a
controller module (101) and a input output (IO) rack and read by the plurality of the
modules in the IO rack;

b) comparing the address on the address bus with the locally set address wherein if the
address do not matches, the module (102) ignores the information and wherein if the
address matches with any of the modules of the plurality of module (102), consequently
the module responds;
c) enabling or disabling a "hand shake out1” signal to high or low mode respectively,
depending on the matching of the address with the locally set address;
d) enabling a signal “hand shake 2” and checking for the status of a “hand shake in”
signal depending on whether the current module of the plurality of module (102) reads the
data;

e) validating the total information received and verifying the check sum wherein the current
module of the plurality of modules (102) responds with data error code if check sum fails;
f) repeating the steps until all the information is transmitted; and
g) disabling a "hand shake out1" signal after all the information has been transmitted.
6. The method of controlling coal feeders in the system (100) as claimed in Claim 5, wherein the
application code has been developed in a Real time Operating System (RTOS).