Title of Invention	A SYSTEM USEFUL FOR ON-LINE MONITORING OF THE CONDITION OF DYNAMIC MACHINES IN HAZARDOUS ENVIRONMENT
Abstract	The present invention provides a device useful for On-line monitoring of the condition of dynamic machines in hazardous environment, which comprises a plurality of transducers, the output of the said transducers being fed to terminal cards, the output of the terminal cards being connected to multiplexer board, the digital output of the said multiplexer board being connected to central processing unit (CPU), the output of the said CPU being connected to a computerized central console through conventional communication port optical isolators and conventional telephone cable, the said multiplexer board, CPU, communication port and optical isolator all of which are located in hazardous area being connected to an intrinsically safe uninterrupted power supply source capable of providing ±5V DC to ±15V, the said computer central console, optical isolator and communication port, being connected to a conventional uninterrupted power source.

Title of Invention

A SYSTEM USEFUL FOR ON-LINE MONITORING OF THE CONDITION OF DYNAMIC MACHINES IN HAZARDOUS ENVIRONMENT

Abstract

The present invention provides a device useful for On-line monitoring of the condition of dynamic machines in hazardous environment, which comprises a plurality of transducers, the output of the said transducers being fed to terminal cards, the output of the terminal cards being connected to multiplexer board, the digital output of the said multiplexer board being connected to central processing unit (CPU), the output of the said CPU being connected to a computerized central console through conventional communication port optical isolators and conventional telephone cable, the said multiplexer board, CPU, communication port and optical isolator all of which are located in hazardous area being connected to an intrinsically safe uninterrupted power supply source capable of providing ±5V DC to ±15V, the said computer central console, optical isolator and communication port, being connected to a conventional uninterrupted power source.

Full Text	The present invention relates to a. useful for on-line Monitoring of the Condition of dynamic machines in hazardous environment. The device of the present invention is a computerised package for continuous health condition monitoring of machines, which are widely distributed in a complex large integrated industry even in hazardous areas such as underground mines. The device of the present invention is specially designed for highly inflammable areas, like gassy coal mines, oil refinery, fertiliser, oil extraction, hydrogen plants etc. falling in category of group I, IIA, IIB and IIC of BIS-5780 and IS-2148. It contains both flameproof and intrinsically safe constituents. The health condition of machine is assessed on the basis of following measurements: 1. Bearing temperature; 2. RPM of machine; 3. Current consumption of machine; 4. Shock pulse assessment for bearings; 5. Vibration of machines. In the present day of industrialisation both production and safety are given top priority. Each dynamic equipment is required to work at its optimum value. This can only be achieved, if the machine has no down time, except during maintenance. If we like to have healthy machine, we shall have to keep watch on it continuously and not checking on routine basis. If we go through statistics on production loss or safety loss, we find that high down time is the root cause, resulting from improper maintenance and recklessness towards health condition of machine. Presently, throughout the world, great care are being taken on assessing health condition of machine routinely. A number of both hand held as well as continuously operating instruments have been developed to measure temperature, vibration, shock pulse from bearing, rpm, current, etc. of machine. Vibration measurement is predominant method for prediction maintenance of dynamic machines, this measurement is utilised in diagonsing possible machine faults, vibration characteristics of a machine are directly related to its condition. The measured vibration signal on an operating machine is complicated in nature, it contains a large amount of information about machine. In the previous technique it is forced to reduce the amount of information contained in measured vibrational signal to a single number, representing the over all value of signal. However, peak value and rms values are most commonly used for condition assessment. Accelerometers, vibration meters, portable data loggers are generally being employed for vibration measurement and its evaluation. The three basic quantities that are measured by instruments are acceleration, velocity and displacement. But in the present invention continuous measurements round the clock are done and analysis are processed on the basis of past and presents status of vibration signal. In certain cases condition of machine is assessed on the basis of bearing temperature measurement using analog display, with thermocouple sensors like Cr-Al, Fe-constantan Pt-Pt/Rh. This type of temperature measurements for one or two bearing and its subsequent display does not help much in diagnosing machine condition. In order to get total picture of bearings employed in the machine, efforts has been made in the present development to put one no of highly rugged RTD sensor with each bearing of the machine and temperature measurement is logged round the clock, for better assessment of machine condition. Similar method using current trasformer as a sensor is employed for display of current consumption of the machine or some time portable tongstester is also employed for the purpose, but none are available for hazardous industries for continuous measurement. Various types of hand held instruments like Tachometer, Shock Pulse meter have also been employed for machine condition diagnosis. But no attempt has been made to integrate essential parameters of a machine to a central processor based system, to give clear picture on machine condition and its developing problem, which may annunciate alarm in case of any likely machine failure. To the best of our knowledge the hitherto known device are not only stand alone device but are not suitable for use in hazardous areas. Hence, there is a definite need for the development of a complete package which may operate continuously in hazardous area. All the available instruments are of discrete type and are mostly based on one or two parameters. Such portable instrument(a) cannot diagnose all the problems, simultaneously, developing in the machine. Besides this hitherto known instrument(s) also do not give past history or trends of developing problem, rather gives some sort of indication on fault on the basis of spot measurements. In most of the cases it has been found, that fault develops gradually and to diagnose the problem trending is must which is generally not available with the known instruments in most of the cases. These type of instruments do not stand reliably for long due, to extreme bad industrial condition. Besides these, available instruments are of general type and is not intrinsically safe and hence can not be used in hazardous industries, available instruments are also not rugged enough to face industrial environment. The main object of the present invention is to provide a device useful for on-line monitoring of the condition of dynamic machines in hazardous environment. Another object of the present invention is to provide a device which is capable of integrating multiple parameters which enables help dynamic diagnosise of the health condition of machines. Yet another object of the present invention is to provide complete diagnosis of developing problem(s), analysis based on machine parameters like vibration, RPM, current, bearing temperature and shock pulse measurements in the form of complete trendings, past records in engineering values, graph, trends, histograms etc, based on menu driven software. Still another object is to provide a device which is intrinsically safe and rugged enough to stand against shock, dust, humidity and vibration and capable of 24 hrs. surveillance on the working machines and annunciates audio-visual alarm much a head of failure of machines to occur. The details schematic diagram of an emodiment of the device has been shown in fig. no. 1 of the drawings. The different constituents as shown in detailed schematic diagram are as follows: 1. Computerised control panel, in Manager's room at a distant place (i.e. 486-work station) under IP 55/56 Standards. 2. Optical isolator incorporated in computerised control panel. 3. 4 wire data communication line. 4. Optical isolator, incorporated in data acquisition system. 5. RS-422 Communication systems for transmitting data to a longer distance and the design is incorporated in CPU/MUX board itself. 6. CPU/UG is microprocessor data acquisition board. The processing system is based on CMOS technology and consumes very low power in mA. The package is self diagnostic type and number of other innovative ideas have been incorporated in CPU board. 7. It is a power line to CPU/UG Board (5V/500mA) from CMRI-UPP. 8. CMRI-UPP: It is a uninterrupted power pack, to provide necessary intrinsically safe power to CPU, Mux board, display system, audio-visual alarm system, sensors, signal conditioners, transmitters. it complies with Indian Standards 2148. 9. Terminal card I to accomodate 32-channels (32 sensors). 10. Intrinsically safe multiplexer board, capable of multiplexing 64-channels. 11. Terminal card II to accomodate rest of 32- channels . 12. Plurality of sensors located at different parts of machine and also to different machines which are located at different locations. Accordingly, the present invention provides a system useful for on-line monitoring of the condition of dynamic machines in hazardous environment, which comprises a plurality of transducers (12)such as herein discribed the output of the said transducers being fed to terminal card(s) (9,11), the output of the terminal cards being connected to multiplexer board (10), the digital output of the said multiplexer board being connected to central processing unit (CPU) (6), the output of the said CPU being connected to a computerised central console (1) through conventional communication port (5) and optical isolation (4,2) and conventional telephone cable (3), the said multiplexer board (10), CPU (6), communication port (5), optical isolator (4), all of which are located in hazardous area being connected to an intrinsically safe uninterrupted power supply source (8) enable of providing +5V DC to ±15V DC, the said computer control console (1), optical isolator (2) and communication port, being connected to a conventional uninterrupted power source. In an embodiment of the present invention, the plurality of transducers used may be such as capable of sensing, bearing temperature, rpm of machine, shock pulse of bearings, vibration of machine, power consumption having signal output of the order of 4-20mA. In another embodiemnt of the present invention, the terminal cards used may be such as having high input impedence for lossless transfer of signals. In yet another embodiment of the present invention the transducers' outputs may be fed to the terminal cards using means such as 2 wire system. In still another embodiment of the present invention the multiplexer board used may consist of multiplexer, decoders, high gain amplifier, decoders and analog to digital converter. In another embodiment of the present invention, the central processing unit used may be such as microprocessor/microcontroller based unit capable of sequential selection, storage, processing of the plurality of transducers outputs. In yet another embodiement, the computerised control console used may be such as having minimum processing speed of at least 66MHz. The intrinsically safe power supply unit used may be such as, that described and claimed in our co-pending Patent Application No. NF-248/96. Each sensor is associated with its respective card for signal conditioning and 4-20mA transmitter to Mux board. Multiplexer system is compatible to any type of sensors having signal output of 4-20mA. The sensors are RTD (Resistance Temperature Detector) temperature sensor, piezo electric vibration sensor, piezo electric shock pulse sensor, inductive type proximity switch and inductive type Hall effect current sensor. CPU/MUX and optically isolated data communication system connected to a distant computer. This system basically comprises of microprocessor based data acquisition system with RAM/ROM, USART/Real time clock calender and optically isolated RS422 communication system. It runs at +5V DC. It is connected to multiplexer board (64 channel) having single channel ADC. It may be connected to any type of sensor, which needs either +15V DC or ±15V DC supply, having signal output of 4-20mA. There is a switching system in Mux board, where single power source of +15V or ±15V DC can be switched sequentially (one by one) to all 64 channels (or sensors). The power supply switching to a particular sensor is programmable through software. Each measurement is stamped with real time clock calender and the generated data can be kept, within the CPU board (64KB RAM/ROM) or can be transmitted to a distant computer through optically isolated R8422 (both end) data communication line. The uninterrupted intrinsically safe power supply unit has a flameproof enclosure having 110V/550V AC supply in underground coal mining environment through cable sealing unit and terminating to intrinsically safe outputs of +5V DC, ±12V to ±15V DC at low amperage. It is an uninterrupted power pack, having Ni-Cad battery (fast charging type) isolator switch, line isolation transformer (550V/110V) primary and 110V AC secondary side, an intelligent battery charger and power supply unit. The intrinsically safe power outputs, such as +5V to +15V DC are used to run CPU/MUX, sensors with signal conditioners/transmitters and alarm system. Only one sensor of any type is in operation at one time and its DC supply requirement is obtained from Mux board, which gets this power from CMRI-UPP unit. The low output from sensor is processed and converted to 4-20ma signal output. The CPU board has facility to provide LCD display (16 characters x 2 lines) giving detailed information on machine health status locally. It can also provide audio-visual alarm in case there is any likely break down of machine or any parameter exceeding its preset limit. The CPU/MUX board can also be used as off-line system, meaning thereby, that it can measure each parameter and can log the measured values with real time clock calender in memory of CPU board. These measured data can be off loaded to a portable memory bank (intrinsically safe), which can further down load, data to a computer through its serial port. The CPU RS422 can continuously communicate with distant computer through 4-core armoured cable. The cable is optically isolated at both ends. The RS422 card is fully compatible to the expansion slots of the computer. The entire CPU/Mux board is housed in MS sheet enclosure having fibre painted with rubber gasket and has air breathing nose, so that it is protected against over heating of the components, shock, dust, humidity and vibration. The different channels are connected through specially designed connectors, which are dust and humidity proof. The entire package is software dependent. All the informations, like past history of measurements, histograms, graphs, trends, engineering values etc are stamped with real time clock calender are available in surface computer. The package is developed on Windows95 and VC++ environment. Another embodiment of the present invention is depicted in schematic fig.2 of the drawing accompanying this specification. Two such or more data stations as shown in figure 2 can be connected to single computer work station through RS422 Serial ports. The details of fig. no.2 are as follows: 1. Computer console, and computer work stations. It is protected against shock dust, humidity, vibration and temperature and as per Standard IP55/56. 3. 4-wire optically isolated armoured data communication line. 12. Pluraty of sensors located at different parts of machine and also to different machines which are located at different areas. 13 and 14. Flame path of flameproof enclosure/dust proof path for DAS enclosure , 15. Power indicator, which can be viewed through toughen glass fixed as per Indian Standard 2148. 16. Operating knob for switching power and fulfils Indian Standards for flame proof enclosure (IS2148). 17. 16 character x 2 lines LCD display indicate, abnormality in machines, existing individual parameter's value in engineering units, health status of individual machine. 18. Visual alarm for parameter exceeding preset limit. 19. Piezo buzzer annunciating alarm in case any parameter exceeding preset limit or there is any abnormality in the machine. 20. Breathing nose having air filter for heat dessipation. 21. 110V AC power supply to CMRI-UPP from main line through cable sealing box. 22. Separate data acquisition and processing system, connected through serial port (RS422) to main computer at a distant place. The following examples are being given by way of illustrations of the device of the present invention and should not be construed to limit the scope of the present invention. The entire set up was developed and integrated in laboratory and was kept under 24 hours continuous operation. Sensors for temperature, rpm, current, shock pulse and vibration were calibrated using simulated condition. Results as displayed in LCD Panel and computer were quite satisfactory. The system ran for one year without any trouble. However, few of the calibration chart as obtained during lab trial has been citedbelow: Temperature Calibration Chart: (Table Removed) Shock Pulse Calibration Chart: (Table Removed) Vibration Calibration Chart: (Table Removed) RPM Calibration Chart: (Table Removed) The system were also tested by Flameproof and Intrinsic Safety Lab for its flameproofness and intrinsic safety and were found to be as per Indian Standards 2148 and 5780. The entire system has also been put to the field trial with J3 Main Mechanical Ventilation Fan at Jeetpur Colliery of Indian Iron and Steel Company. The system is in continuous operation for last one and half years and found to be very much useful where machine failures were predicted in advance and costly break down could be averted by changing one of bearings of main mechanical ventilation fan of IISCO Colliery, Jeetpur. Novel features and advantages of the device: 1. The device of the present invention are specially designed for hazardous and highly inflammable areas comprising of Gr.I, HA, IIB and IIC. It is highly rugged and comply with Indian Standards 2148, 5780, 13019 and IP 55/56. It keeps 24 hrs. close surveillance on each machine, connected to it. To the best of our knowledge, no one system exists in the world for hazardous area, monitoring health condition continuously with respect to its bearing temperature, bearing film condition, vibration of machine, RPM of machine and current consumption of the machine. 2. The system is software dependent and computer controlled. 3. The system can transmit data upto a distance of 5 km or even more, without using MODEM. The communication line is optically isolated and there is no risk in using, this line in hazardous area. 4. The development and integration is done in small modules to facilitate ease of maintenance and replacement of defective modules, very conveniently in extremely difficult situation. 5. Switching of single power source to different sensor is programmable. 6. Preventive/prediction maintenance is intiated as a result of knowledge of the condition of a machine from its continuous checking. Condition of all important components are analysed for trends, so that warnings of incipient troubles are received before hand for effective and timely action eliminating costly break down. 7. The system is highly cost effective. 8. The system is intrinsically safe. 9. The system has provision to down load measured information to another memory bank and can be used even without communication cable. 10. It is versatile system and can accomodate any kind of sensors, having 4-20mA output. 11. The system is self diagnostic type, to check any fault developed within the device itself. We Claim: 1. A system useful for on-line monitoring of the condition of dynamic machines in hazardous environment, which comprises a plurality of transducers (12) of the kind such as herein described, the output of the said transducers being fed to terminal cards (9,11), the output of the terminal cards being connected to multiplexer board (10), the digital output of the said multiplexer board being connected to central processing unit (CPU) (6), the output of the said CPU being connected to a computerized central console (1) through conventional communication port (5) optical isolators (4,2) and conventional telephone cable (3), the said multiplexer board (10), CPU (6), communication port (5) and optical isolator (4) all of which are located in hazardous area being connected to an intrinsically safe uninterrupted power supply source (8) capable of providing ±5V DC to ±15V, the said computer central console (1), optical isolator (2) and communication port, being connected to a conventional uninterrupted power source. 2. A system as claimed in claim 1, wherein the terminal cards used have high input impedance for lossless transfer of signals. 3. A system as claimed in claim 1, wherein the transducers outputs are fed to the terminal cards using 2 wire system. 4. A system as claimed in claim 1, wherein the multiplexer board used consist of multiplexer, decoders, high gain amplifier, decoders and analog to digital converter. 5. A system as claimed in claim 1, wherein the central processing unit (CPU) used comprises of microprocessor/microcontroller based unit, capable of sequential selection, storage, processing of the plurality of transducer outputs. 6. A system as claimed in claim 1, wherein computer control console used has processing speed of at least 66MHz. 7. A system useful for on-line monitoring of the condition of dynamic machines in hazardous environment, substantially as herein described with reference to the examples and drawings accompanying this specification.

Full Text

The present invention relates to a.
useful for on-line Monitoring of the Condition of dynamic machines in hazardous environment.
The device of the present invention is a computerised package for continuous health condition monitoring of machines, which are widely distributed in a complex large integrated industry even in hazardous areas such as underground mines. The device of the present invention is specially designed for highly inflammable areas, like gassy coal mines, oil refinery, fertiliser, oil extraction, hydrogen plants etc. falling in category of group I, IIA, IIB and IIC of BIS-5780 and IS-2148.
It contains both flameproof and intrinsically safe constituents.
The health condition of machine is assessed on the basis of following measurements:
1. Bearing temperature;
2. RPM of machine;
3. Current consumption of machine;
4. Shock pulse assessment for bearings;
5. Vibration of machines.
In the present day of industrialisation both production and safety are given top priority.

Each dynamic equipment is required to work at its optimum value. This can only be achieved, if the machine has no down time, except during maintenance. If we like to have healthy machine, we shall have to keep watch on it continuously and not checking on routine basis. If we go through statistics on production loss or safety loss, we find that high down time is the root cause, resulting from improper maintenance and recklessness towards health condition of machine.
Presently, throughout the world, great care are being taken on assessing health condition of machine routinely. A number of both hand held as well as continuously operating instruments have been developed to measure temperature, vibration, shock pulse from bearing, rpm, current, etc. of machine.
Vibration measurement is predominant method for prediction maintenance of dynamic machines, this measurement is utilised in diagonsing possible machine faults, vibration characteristics of a machine are directly related to its condition.
The measured vibration signal on an operating machine is complicated in nature, it contains a large amount of information about machine. In the previous technique it is forced to reduce the amount of

information contained in measured vibrational signal to a single number, representing the over all value of signal. However, peak value and rms values are most commonly used for condition assessment.
Accelerometers, vibration meters, portable data loggers are generally being employed for vibration measurement and its evaluation. The three basic quantities that are measured by instruments are acceleration, velocity and displacement.
But in the present invention continuous measurements round the clock are done and analysis are processed on the basis of past and presents status of vibration signal.
In certain cases condition of machine is assessed on the basis of bearing temperature measurement using analog display, with thermocouple sensors like Cr-Al, Fe-constantan Pt-Pt/Rh. This type of temperature measurements for one or two bearing and its subsequent display does not help much in diagnosing machine condition. In order to get total picture of bearings employed in the machine, efforts has been made in the present development to put one no of highly rugged RTD sensor with each bearing of the machine and temperature measurement is logged round the clock, for better

assessment of machine condition.
Similar method using current trasformer as a
sensor is employed for display of current consumption of the machine or some time portable tongstester is also employed for the purpose, but none are available for hazardous industries for continuous measurement.
Various types of hand held instruments like Tachometer, Shock Pulse meter have also been employed for machine condition diagnosis. But no attempt has been made to integrate essential parameters of a machine to a central processor based system, to give clear picture on machine condition and its developing problem, which may annunciate alarm in case of any likely machine failure.
To the best of our knowledge the hitherto known device are not only stand alone device but are not suitable for use in hazardous areas. Hence, there is a definite need for the development of a complete package which may operate continuously in hazardous area.
All the available instruments are of discrete type and are mostly based on one or two parameters. Such portable instrument(a) cannot diagnose all the problems, simultaneously, developing in the machine. Besides this hitherto known instrument(s) also do not give past history or trends of developing

problem, rather gives some sort of indication on fault on the basis of spot measurements.
In most of the cases it has been found, that fault develops gradually and to diagnose the problem trending is must which is generally not available with the known instruments in most of the cases. These type of instruments do not stand reliably for long due, to extreme bad industrial condition. Besides these, available instruments are of general type and is not intrinsically safe and hence can not be used in hazardous industries, available instruments are also not rugged enough to face industrial environment.
The main object of the present invention is to provide a device useful for on-line monitoring of the condition of dynamic machines in hazardous environment.
Another object of the present invention is to provide a device which is capable of integrating multiple parameters which enables help dynamic diagnosise of the health condition of machines.
Yet another object of the present invention is to provide complete diagnosis of developing problem(s), analysis based on machine parameters like vibration, RPM, current, bearing temperature and shock pulse

measurements in the form of complete trendings, past records in engineering values, graph, trends, histograms etc, based on menu driven software.
Still another object is to provide a device which is intrinsically safe and rugged enough to stand against shock, dust, humidity and vibration and capable of 24 hrs. surveillance on the working machines and annunciates audio-visual alarm much a head of failure of machines to occur.
The details schematic diagram of an emodiment of the device has been shown in fig. no. 1 of the drawings. The different constituents as shown in detailed schematic diagram are as follows:
1. Computerised control panel, in Manager's room at a
distant place (i.e. 486-work station) under IP
55/56 Standards.
2. Optical isolator incorporated in computerised
control panel.
3. 4 wire data communication line.
4. Optical isolator, incorporated in data acquisition
system.
5. RS-422 Communication systems for transmitting data
to a longer distance and the design is
incorporated in CPU/MUX board itself.

6. CPU/UG is microprocessor data acquisition board.
The processing system is based on CMOS technology
and consumes very low power in mA. The package is
self diagnostic type and number of other
innovative ideas have been incorporated in CPU
board.
7. It is a power line to CPU/UG Board (5V/500mA) from
CMRI-UPP.
8. CMRI-UPP: It is a uninterrupted power pack, to
provide necessary intrinsically safe power to CPU,
Mux board, display system, audio-visual alarm
system, sensors, signal conditioners,
transmitters. it complies with Indian Standards
2148.
9. Terminal card I to accomodate 32-channels (32
sensors).
10. Intrinsically safe multiplexer board, capable of
multiplexing 64-channels.
11. Terminal card II to accomodate rest of 32-
channels .
12. Plurality of sensors located at different parts
of machine and also to different machines which
are located at different locations.

Accordingly, the present invention provides a
system useful for on-line monitoring of the condition
of dynamic machines in hazardous environment, which
comprises a plurality of transducers (12)such as herein discribed
the output
of the said transducers being fed to terminal card(s) (9,11), the output of the terminal cards being connected to multiplexer board (10), the digital output of the said multiplexer board being connected to central processing unit (CPU) (6), the output of the said CPU being connected to a computerised central console (1) through conventional communication port (5) and optical isolation (4,2) and conventional telephone cable (3), the said multiplexer board (10), CPU (6), communication port (5), optical isolator (4), all of which are located in hazardous area being connected to an intrinsically safe uninterrupted power supply source (8) enable of providing +5V DC to ±15V DC, the said computer control console (1), optical isolator (2) and communication port, being connected to a conventional uninterrupted power source.
In an embodiment of the present invention, the plurality of transducers used may be such as capable of sensing, bearing temperature, rpm of machine, shock pulse of bearings, vibration of machine, power

consumption having signal output of the order of 4-20mA.
In another embodiemnt of the present invention, the terminal cards used may be such as having high input impedence for lossless transfer of signals.
In yet another embodiment of the present invention the transducers' outputs may be fed to the terminal cards using means such as 2 wire system. In still another embodiment of the present invention the multiplexer board used may consist of multiplexer, decoders, high gain amplifier, decoders and analog to digital converter.
In another embodiment of the present invention, the central processing unit used may be such as microprocessor/microcontroller based unit capable of sequential selection, storage, processing of the plurality of transducers outputs.
In yet another embodiement, the computerised control console used may be such as having minimum processing speed of at least 66MHz.
The intrinsically safe power supply unit used may be such as, that described and claimed in our co-pending Patent Application No. NF-248/96.

Each sensor is associated with its respective card for signal conditioning and 4-20mA transmitter to Mux board.
Multiplexer system is compatible to any type of sensors having signal output of 4-20mA.
The sensors are RTD (Resistance Temperature Detector) temperature sensor, piezo electric vibration sensor, piezo electric shock pulse sensor, inductive type proximity switch and inductive type Hall effect current sensor.
CPU/MUX and optically isolated data communication system connected to a distant computer. This system basically comprises of microprocessor based data acquisition system with RAM/ROM, USART/Real time clock calender and optically isolated RS422 communication system. It runs at +5V DC. It is connected to multiplexer board (64 channel) having single channel ADC. It may be connected to any type of sensor, which needs either +15V DC or ±15V DC supply, having signal output of 4-20mA.
There is a switching system in Mux board, where single power source of +15V or ±15V DC can be switched sequentially (one by one) to all 64 channels (or sensors). The power supply switching to a particular

sensor is programmable through software. Each measurement is stamped with real time clock calender and the generated data can be kept, within the CPU board (64KB RAM/ROM) or can be transmitted to a distant computer through optically isolated R8422 (both end) data communication line.
The uninterrupted intrinsically safe power supply unit has a flameproof enclosure having 110V/550V AC supply in underground coal mining environment through cable sealing unit and terminating to intrinsically safe outputs of +5V DC, ±12V to ±15V DC at low amperage. It is an uninterrupted power pack, having Ni-Cad battery (fast charging type) isolator switch, line isolation transformer (550V/110V) primary and 110V AC secondary side, an intelligent battery charger and power supply unit. The intrinsically safe power outputs, such as +5V to +15V DC are used to run CPU/MUX, sensors with signal conditioners/transmitters and alarm system.
Only one sensor of any type is in operation at one time and its DC supply requirement is obtained from Mux board, which gets this power from CMRI-UPP unit. The low output from sensor is processed and converted to 4-20ma signal output.

The CPU board has facility to provide LCD display (16 characters x 2 lines) giving detailed information on machine health status locally. It can also provide audio-visual alarm in case there is any likely break down of machine or any parameter exceeding its preset limit.
The CPU/MUX board can also be used as off-line system, meaning thereby, that it can measure each parameter and can log the measured values with real time clock calender in memory of CPU board. These measured data can be off loaded to a portable memory bank (intrinsically safe), which can further down load, data to a computer through its serial port.
The CPU RS422 can continuously communicate with distant computer through 4-core armoured cable. The cable is optically isolated at both ends. The RS422 card is fully compatible to the expansion slots of the computer.
The entire CPU/Mux board is housed in MS sheet enclosure having fibre painted with rubber gasket and has air breathing nose, so that it is protected against over heating of the components, shock, dust, humidity and vibration.

The different channels are connected through specially designed connectors, which are dust and humidity proof.
The entire package is software dependent. All the informations, like past history of measurements, histograms, graphs, trends, engineering values etc are stamped with real time clock calender are available in surface computer. The package is developed on Windows95 and VC++ environment.
Another embodiment of the present invention is depicted in schematic fig.2 of the drawing accompanying this specification.
Two such or more data stations as shown in figure 2 can be connected to single computer work station through RS422 Serial ports.
The details of fig. no.2 are as follows: 1. Computer console, and computer work stations. It
is protected against shock dust, humidity,
vibration and temperature and as per Standard
IP55/56. 3. 4-wire optically isolated armoured data
communication line. 12. Pluraty of sensors located at different parts of
machine and also to different machines which are
located at different areas.

13 and 14. Flame path of flameproof enclosure/dust proof path for DAS enclosure ,
15. Power indicator, which can be viewed through
toughen glass fixed as per Indian Standard 2148.
16. Operating knob for switching power and fulfils
Indian Standards for flame proof enclosure
(IS2148).
17. 16 character x 2 lines LCD display indicate,
abnormality in machines, existing individual
parameter's value in engineering units, health
status of individual machine.
18. Visual alarm for parameter exceeding preset limit.
19. Piezo buzzer annunciating alarm in case any
parameter exceeding preset limit or there is any
abnormality in the machine.
20. Breathing nose having air filter for heat
dessipation.
21. 110V AC power supply to CMRI-UPP from main line
through cable sealing box.
22. Separate data acquisition and processing system,
connected through serial port (RS422) to main
computer at a distant place.
The following examples are being given by way of illustrations of the device of the present invention

and should not be construed to limit the scope of the present invention.
The entire set up was developed and integrated in laboratory and was kept under 24 hours continuous operation. Sensors for temperature, rpm, current, shock pulse and vibration were calibrated using simulated condition. Results as displayed in LCD Panel and computer were quite satisfactory. The system ran for one year without any trouble. However, few of the calibration chart as obtained during lab trial has been citedbelow:
Temperature Calibration Chart:

(Table Removed)
Shock Pulse Calibration Chart:

(Table Removed)
Vibration Calibration Chart:
(Table Removed)
RPM Calibration Chart:
(Table Removed)

The system were also tested by Flameproof and Intrinsic Safety Lab for its flameproofness and intrinsic safety and were found to be as per Indian Standards 2148 and 5780.
The entire system has also been put to the field trial with J3 Main Mechanical Ventilation Fan at Jeetpur Colliery of Indian Iron and Steel Company. The system is in continuous operation for last one and half years and found to be very much useful where machine failures were predicted in advance and costly break down could be averted by changing one of bearings of main mechanical ventilation fan of IISCO Colliery, Jeetpur.

Novel features and advantages of the device:
1. The device of the present invention are specially
designed for hazardous and highly inflammable
areas comprising of Gr.I, HA, IIB and IIC. It is
highly rugged and comply with Indian Standards
2148, 5780, 13019 and IP 55/56. It keeps 24 hrs.
close surveillance on each machine, connected to
it. To the best of our knowledge, no one system
exists in the world for hazardous area, monitoring
health condition continuously with respect to its
bearing temperature, bearing film condition,
vibration of machine, RPM of machine and current
consumption of the machine.
2. The system is software dependent and computer
controlled.
3. The system can transmit data upto a distance of 5
km or even more, without using MODEM. The
communication line is optically isolated and there
is no risk in using, this line in hazardous area.
4. The development and integration is done in small
modules to facilitate ease of maintenance and
replacement of defective modules, very
conveniently in extremely difficult situation.
5. Switching of single power source to different
sensor is programmable.
6. Preventive/prediction maintenance is intiated as a
result of knowledge of the condition of a machine
from its continuous checking. Condition of all
important components are analysed for trends, so
that warnings of incipient troubles are received
before hand for effective and timely action
eliminating costly break down.
7. The system is highly cost effective.
8. The system is intrinsically safe.
9. The system has provision to down load measured
information to another memory bank and can be used
even without communication cable.
10. It is versatile system and can accomodate any kind
of sensors, having 4-20mA output.
11. The system is self diagnostic type, to check any
fault developed within the device itself.

We Claim:
1. A system useful for on-line monitoring of the condition of dynamic machines in
hazardous environment, which comprises a plurality of transducers (12) of the kind such
as herein described, the output of the said transducers being fed to terminal cards (9,11),
the output of the terminal cards being connected to multiplexer board (10), the digital
output of the said multiplexer board being connected to central processing unit (CPU) (6),
the output of the said CPU being connected to a computerized central console (1) through
conventional communication port (5) optical isolators (4,2) and conventional telephone
cable (3), the said multiplexer board (10), CPU (6), communication port (5) and optical
isolator (4) all of which are located in hazardous area being connected to an intrinsically
safe uninterrupted power supply source (8) capable of providing ±5V DC to ±15V, the
said computer central console (1), optical isolator (2) and communication port, being
connected to a conventional uninterrupted power source.
2. A system as claimed in claim 1, wherein the terminal cards used have high input
impedance for lossless transfer of signals.
3. A system as claimed in claim 1, wherein the transducers outputs are fed to the terminal
cards using 2 wire system.
4. A system as claimed in claim 1, wherein the multiplexer board used consist of
multiplexer, decoders, high gain amplifier, decoders and analog to digital converter.
5. A system as claimed in claim 1, wherein the central processing unit (CPU) used
comprises of microprocessor/microcontroller based unit, capable of sequential selection,
storage, processing of the plurality of transducer outputs.
6. A system as claimed in claim 1, wherein computer control console used has processing
speed of at least 66MHz.
7. A system useful for on-line monitoring of the condition of dynamic machines in
hazardous environment, substantially as herein described with reference to the examples
and drawings accompanying this specification.

Documents:

2148-del-1998-abstract.pdf

2148-del-1998-claims.pdf

2148-del-1998-complete specification (granted).pdf

2148-del-1998-correspondence-others.pdf

2148-del-1998-correspondence-po.pdf

2148-del-1998-description (complete).pdf

2148-del-1998-drawings.pdf

2148-del-1998-form-1.pdf

2148-del-1998-form-19.pdf

2148-del-1998-form-2.pdf

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Patent Number

232492

Indian Patent Application Number

2148/DEL/1998

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

17-Mar-2009

Date of Filing

24-Jul-1998

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	RAM JIWAN JAISWAL	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.
2	EMMANUEL TUDU	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.
3	RAJENDRA PRASAD	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.
4	RADHA NATH DAS	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.
5	BHARAT BHUSHAN DHAR	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.
6	RADHEY SHYAM SRIVASTAVA	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.
7	JAIPATI MONDAL	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD-826 001, INDIA.

PCT International Classification Number

G06F 9/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA