Abstract:
A system for monitoring machine data which avoids the need for the cumbersome placement of junction boxes adjacent machines that heretofore had required installing the junction boxes on walls, studs, or stanchions. Instead, a rigid conduit having conductors therein communicate with an integrated sealed instrument package that allows the conductors&#39; communication between an asset such as a machine to be monitored via transducers to a signal processor at a remote location. A multiplicity of assets can be monitored through this arrangement by providing signal differentiation for the various machines.

Description:
FIELD OF THE INVENTION 
     The following invention relates generally to routing communication systems which link instrumentalities together. More specifically, the instant invention is directed to a conduit network having conductors running therethrough and an instrument package which accesses the conductors and routes information to the conductors from measuring transducers strategically deployed on assets including machinery to be monitored. 
     BACKGROUND OF THE INVENTION 
     Industrial plants, such as chemical processing facilities and power generation plants utilize pumps, compressors, generators, turbines and the like which need to be maintained. The best form of maintenance is preventative maintenance, and to achieve that goal, accurate diagnostic procedures should be in place which signal the onset of machine anomalies while they can still be repaired economically. One efficient method to provide accurate diagnostic procedures is to have at least one central processing system operatively coupled to a permanently installed data collection system interacting with assets including machinery and throughout the plant or facility. Thus, the ability to conveniently identify and diagnose possible asset problems from any location at any time is realized. That means finding potential malfunctions as soon as possible for efficient planning of maintenance. 
     However, retrofitting existing assets with a permanently installed data collection system to provide a link between the machinery being monitored and the processing system has traditionally been quite costly and time consuming as a result of the cost due to enclosures, conduit fittings, conduit runs near the monitored machines and the cost due to the labor required for this installation. 
     For example, FIG. 1 reflects a prior art junction box which must be wall mounted, located on a stud, or other type of support. Other techniques first require securing by means of first installing an upstanding stanchion adjacent the machine so that hardwiring can communicate from the transducer to the signal processor through the junction box and associated conduit. The routing and wiring of the communications link through these junction boxes has been historically a labor intensive and costly endeavor. 
     A need therefore exists for an improved means for allowing communication between a diagnostic transducer and the signal processor located at a remote location from the transducer. 
     The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant&#39;s acknowledged duty to disclose relevant, prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed. 
     Other Prior Art (Including Author, Title, Date, Pertinent Pages, Etc.)  Orbit  magazine, Marco Alcalde, “New Trendmaster® 2000 flexiTIM: Simplified Design Significantly Reduces Costs”, June, 1997, Page 33. 
     SUMMARY OF THE INVENTION 
     The instant invention is directed to a means and method for quickly and economically providing a communication link between an asset such as machinery being monitored and a processor means which receives signals from a transducer strategically located at the machine or other asset so that signals can be transmitted to the processor means to determine machine status. 
     A rigid conduit protects communication links, for example, conductors disposed therewithin. In one embodiment, the conduit includes an opening allowing access to the conductors. The opening is contoured to receive a sealing gasket about its outer periphery. The gasket in turn receives an electronic instrument package which attaches to the opening on the conduit in sealing engagement by sandwiching the gasket between the instrument package and the periphery circumscribing the opening on the conduit. The instrument package includes circuitry which communicates with cabling that leads to sensors such as transducers used to monitor machinery or other assets. The interior of the instrument package includes a well within which potting compound can be deployed. Thus, the instrument package circuitry is tightly sealed prohibiting the throughpassage of contamination within the instrument package. Sealing the exterior environment from the interior of the instrument package and conduit provides a durable, rugged and reliable communication system. The electronic instrument package is substantially easier to install than the prior art systems and appreciably more economical initially and subsequently for maintenance. 
     OBJECTS OF THE INVENTION 
     Accordingly, it is an object of the instant invention to provide a new and novel system for monitoring machine data. 
     A further object of the instant invention is to provide an integrated instrument package and conduit system. 
     A further object of the instant invention is to provide that which has been characterized above that is durable in construction, comparatively easy to install and appreciably less expensive than prior art systems. 
     A further object of the instant invention is to provide that which has been characterized above which obviates the need for junction boxes and the attendant requirements that junction boxes be mounted on walls, studs, stanchions or the like. 
     Viewed from a first vantage point a system for monitoring machine data, comprising, in combination: a plurality of machines to be monitored, sensor means operatively coupled to each of said plural machines, each said sensor means delivering an output signal correlative of the machine data, and conduit means extending proximate to said sensor means and leading to a signal processor, said conduit means including a sealed instrument package allowing communication between said sensors and said signal processor via signal conductors passing from said sensor means, through said instrument package and to said signal processor. 
     Viewed from a second vantage point an integrated instrument package and conduit, comprising, in combination: conductors running through said conduit, an opening in said conduit exposing terminals of said conductors, and sealing means between said conduit opening and said instrument package, said instrument package including connectors removably attachable to said terminals and leading through said instrument package to a sensing transducer. 
     These and other objects will be made manifest when considering the following detailed specification when taken in conjunction with the appended drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the prior art junction box. 
     FIG. 2 is a schematic of the system according to the instant invention. 
     FIG. 3 is a block diagram according to the instant invention providing greater detail from FIG.  2 . 
     FIG. 4 is a further block diagram showing a distributed control system according to the instant invention. 
     FIG. 5 is a branching diagram showing how a multiplicity of the integrated instrument packages and the conduits can be linked both serially and in parallel. 
     FIG. 6 is a sectional view showing the conduit and instrument package deployed. 
     FIG. 7 is a perspective view of the integrated package inverted showing a bottom face thereof. 
     FIG. 8 is an exploded parts perspective view of the integrated instrument package according to the instant invention. 
     FIG. 9 is an alternative exploded parts perspective view of the integrated instrument package according to the instant invention. 
     FIG. 10 is a general block diagram in respect of the operating elements shown in FIG.  8 . 
     FIG. 11 is a block diagram which provides greater detail than that which is shown in FIG.  10 . 
     FIGS. 12 through 15 are block diagrams which provide greater detail than that which is shown in FIG.  11 . 
     FIGS. 16 and 17 are schematics of one circuit which can be used to implement that which is shown in FIGS. 10 through 15. 
     FIG. 18 is a sectional view showing the conduit and an alternative instrument package deployed. 
     FIGS. 19 and 20 are exploded parts perspective views of the integrated instrument package shown in FIG.  18 . 
     FIG. 21 is a block diagram of the instrument package electronic means for thermocouple and RTD embodiments according to the instant invention. 
     FIG. 22 is a block diagram of the instrument package electronic means for a dual pressure embodiment according to the instant invention. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Considering the drawings, wherein like reference numerals refer to like parts throughout the various drawing figures, reference numeral  10  is directed to the system for monitoring machine data according to the instant invention. 
     In its essence, and referring to FIGS. 2 and 3, status of the machinery  12  is being monitored by a signal processor  100  via signals engendered from a plurality of transducers  16  strategically placed in areas of the machinery which have been correlated with zones of know proclivities toward ware. The transducers  16  communicate to the signal processor  100  via transducer cables  18  which lead to the signal processor  100  via a conduit  22  having conductors  24  disposed therein. The conductors  24  communicate with the transducer cables  18  through electronic means  160  disposed in an interior of an instrument packaged  20  shown in greater detail in FIGS. 10 through 17. Note that the instrument package can be coupled to the conduit in a vertical angel, a horizontal angle or at any angle therebetween. 
     More specifically, and referring to FIG. 3, status of machinery  12  and plant asset  32  is being monitored by a signal processor or data acquisition system  100  via signals generated from transducers  16  strategically located in areas to be monitored. The transducers  16  communicate to the signal processor or data acquisition system  100  via transducer cables  18  being operatively coupled to the instrument packages  20  which in turn are coupled to the data acquisition system via conductors  24  which stream through the conduit  22 . The protocol employed for the system communication cables  24  located in the conduit  22  can be a fieldbus protocol, a modbus protocol, a canbus protocol or proprietary. The data acquisition system can be coupled to a host computer system  110  via a computer link such as a ISA bus, PCI bus, ethernet, IEEE-1392, USB or an RS-232 link. 
     Alternatively, and referring to FIG. 4, the transducers  16  can communicate to a distributed control system (DCS)  112  via the transducer cables  18  which lead to the distributed control system  112  via instrument packages  20  and conductors  24  housed in conduit  22 . The conductors  24  communicate with the transducer cables  18  through the electronic means  120  housed within the instrument packages  20 . Thus, the status of the machinery  12  and plant assets  32  maybe monitored by the distributed control system  112 . The distributed control system provides a computerized/integrated manufacturing/process system. 
     FIG. 5 outlines one possible branching diagram allowing a multiplicity of transducers and a multiplicity of machines and assets to be monitored simultaneously by a single signal processor  100 . As show in FIG. 5, one row of instrument packages are aligned in series while a second row can be linked in parallel. This is possible because there is a third connector cluster according to the instant invention and as shown in FIG.  6 . 
     Referring to FIG. 6, each instrument package  20  communicates with the conductors  24  contained within the ridged conduit  22  via a conduit body  40  formed in the conduit  22 . The conduit body  40  includes first and seconds ferules  42  at opposite sides of the body  40  and transition in overlying engagement with the rigid conduit  22  at both ends thereof. The body  40  itself is substantially tub shaped having an opening  44  allowing access to connectors  26  terminating at extremities of the conductors  24 . The opening  44  of the conduit body has a peripheral ledge  46  which receives a substantially rectangular gasket  150  thereover (please see FIG.  7 ). The gasket  150  includes enlarged end portions  50  having holes  52  therein to receive screws  54  which pass through a flange  60  integrally formed on a casing or housing  62  which defines a portion of the instrument package  20 . Transducer cables  18  extend from a top wall  64  of the housing  62  via fittings  140 . A rounded peripheral edge or boundary  66  provides the transitional area between the top wall  64  lying in a first plane and the housing  62  having four connected walls lying in a second plane substantially perpendicular to the first plane. FIG. 6 shows three clusters of connectors  26  associated with conductors  24 . Preferably, each cluster includes five connectors  26  associated with five conductors  24 . 
     More particularly, the reference numerals will not be belabored herein. The connectors  26  shown in FIGS. 5 and 6 are one, two and three in number. Each connector  26  includes a cluster of five wires and each has a coupling  28  complemental to the receiving areas of terminal blocks  122  shown in FIGS. 7 through 9. The terminal block  122  in turn communicates with a circuit board to be described and allows both serial and parallel connection between adjacent integrated instrument packages  20 . The terminal blocks  122  pass through a stainless steal label and support plate  124  having a plurality of portals including three portals  126  providing clearance for the terminal blocks  122 . Another portal  128  provides clearance for a switch  130  having a protective membrane thereover to pass therethrough. 
     Referring to FIG. 8, the terminal blocks are placed in mating engagement with headers  123  mounted on a circuit board  134 . The circuit board  134  is preferably divided up into a plurality of boards which are hinged to fold in an accordion manner. One or more threaded connectors  140  pass through the top wall  64  of the housing  62  and are connected to a lower most section of the circuit board  134 . The threaded connectors  140  are fixed in place by means of nuts  144  which engage an exterior top surface of the top wall  64 . 
     Alternatively, and referring to FIG. 10, the threaded cable connectors  140  which lead to the transducers could be placed on the exterior of the housing  62  with the retaining nuts  144  placed on the inside if desired. Cable conductors  142  would then pass through the top wall  64  of the housing  62  to interconnect the lower most section of the circuit board  134  to the threaded cable connector. Note that gasket  150  is substantially oval in shape and includes three transfers gasket membranes  152  connecting long sides of the oval gasket and extending between adjacent strip terminal blocks  122 . An opening is provided to allow access to the switch  130 . 
     Referring to FIG. 7, a potting material  158  envelopes all of the hardware within the interior of the housing  62 . Thus, the potting material provides support, insulation and protection for the interior hardware. Furthermore, the potting material provides ruggedness to the instrument package and precludes fluid ingression to the electronics contained within the housing  62 . Preferably, the potting is an epoxy which is poured in as a liquid and heat cured to reach a state of solidification. Alternatively, the internal hardware may be sealed with O rings or the internal hardware maybe affixed together and then to plate  124 . 
     Referring to FIG. 10, a general block diagram of the instrument package electronic means  160  is shown operatively coupled between the transducers  16  and a data collection system  100 , 110  or  120 . The instrument package electronic means  160  includes signal conditioning circuitry means  170  interfacing between transducers  16  and a communication interface  270 . The communication interface  270  couples the signal conditioning circuitry means  170  to the data collection system. 
     In one embodiment, and referring to FIG. 11, each signal conditioning circuit means  170  includes a transducer interface module  180 , a transducer power and current limiting module, an integrator module  210  and a channel check module  220 . The transducer interface module  180  operatively couples the integrator and check modules to a bus structure  272  of the communication interface  270 . 
     Referring to FIGS. 12 and 16, the transducer interface module  180  includes a voltage regulator  182 , a transducer interface module power means  184 , an oscillator  186 , control logic  188 , a differential receiver  190 , a multiplexer  192 , a window comparator  194 , line drivers  196  and a undedicated op-amp  198 . The transducer interface module power means provides the necessary power for the components on the module by receiving a regulated voltage from the voltage regulator being driven by a diode bridge connected to power lines of the conductors  24 . The control logic  188  is powered by the transducer interface module power means  184  and receives a timing or clock signal from the oscillator module  186  operatively coupled to an external crystal. The DIP switch  130  is connected to the control logic for providing a unique address for the transducer interface module  180 . The differential receiver  190  is coupled to the control logic and serves to interface the signal from the processor  100 ,  120  to the control logic. The multiplexer  192  is connected to the control logic  188 , the transducer signal conditioner  170  and the line drivers  196 . The multiplexer, under the orchestration of the control logic sends a high calibration signal, a low calibration signal or a conditioned transducer signal to the line drivers  196  which drive the appropriate conductors  24  to transmit these respective signals to the processor  100 , 120 . A widow comparator  194  is coupled between the control logic  188  and the line drivers  196  to enable or disable the line drivers under predetermined conditions. The control logic orchestrates the operations of the transducer interface module  180 . 
     Referring to FIGS. 11 and 13, one transducer power and current limiting module  200  is operatively coupled to each transducer  16 . Specifically, the transducer power and current limiting module  200  includes a current sensor  202 , a control amplifier  204 , a current limiter  206  and a common short protection module  208 . The current sensor  202  is operatively coupled to the transducer interface module power supply  178 , the control amplifier  204  and the current limiter  206 . The control amplifier  204  is in turn operatively coupled the current limiter  206 . The current sensor  202  senses the current being received from the power supply  178  and delivers the current to the current limiter  206  and control amplifier  204 . The current limiter  206  delivers current to the transducer  16  under the control of the control amplifier  204 . The common short protection module  208  is operatively coupled to the common of the transducer for providing short circuit protection. 
     Referring to FIGS. 11 and 14, the integrator module  210  includes a differential integrator and a high pass filter module  212  operatively coupled to transducer  16  in the form of a differential accelerometer. A gain stage  214  is operatively coupled to integrator and high pass filter module  212 . Thus, the integrator and high pass filter module  212  integrates and filters the transducer signal which is amplified by gain stage  214  before being sent to the transducer interface module  180  as a scaled velocity output. 
     Referring to FIGS. 11 and 15, the OK check modules  220  includes a signal averager and a window comparator. The signal averager  222  is operatively coupled to the transducer  16  and takes the average of the differential signals provided by the transducer  16  when it takes the form of a differential accelerometer. The signal averager  222  is in turn coupled to the window comparator  224  which compares the averaged signal to a high and low reference. Based on this comparison the widow comparator  224  outputs an OK/NOT OK signal to the transducer interface module  180 . 
     More specifically, FIGS. 16 and 17 shows a detailed schematic of one embodiment of the instrument package electronic means  160 . Note that FIG. 17 only shows the electronics for channel A as a result of the electronics for channel B being identical to that shown for channel A. 
     Referring to FIGS. 10 and 16, the main goal of the communication interface is to operatively couple the signal conditioning circuitry  170  to the data collection system  100 ,  120 . The communication interface includes an bus  272  which is operatively coupled to the signal conditioning circuitry  170 . In this embodiment, the signal conditioning circuitry includes two channels operatively coupled to a pair of differential accelerometer transducers labeled transducer A and transducer B. 
     FIG. 17, shows a detailed schematic the transducer power and current limiting module  200 , the integrator module  210  and the channel check module  220 . The transducer power and current liming module  200  provides power to transducer A and limits the current to transducer A should a fault occur. The integrator module  210  integrates the signals received from the transducer and provides gain thereto for providing an output signal to the transducer interface module  180  which intern outputs a conditioned signal to the bus system  272 . The okay channel check module  220  assures proper operation of transducer A and communicates this proper operation to the transducer interface module  180  which in turn can communicate the condition of transducer A to the data collection via the bus system  272 . The circuitry operatively coupled between transducer B and the bus system works in a similar manner as described hereinabove for transducer A. FIG. 16 shows a detailed schematic of channel A and channel B transducer interface modules  180 , the transducer and interface power supply and the bus system  272 . 
     Each transducer interface module  180  has a unique address associated therewith by setting the binary DIP switch  130 . Preferably, the switch is an eight position binary switch. Address 1 through 255 are valid for transducer interface modules  180  connected to the processor  100 , 120 . During data collection the signal processor searches a line for the specific transducer interface module address and powers it. A reading of current data is taken from that measurement point and transferred to the processor  100  or  120  for processing. After all necessary processing has occurred, the transducer interface module  180  is then powered down and then the processor  100  or  120  searches for the next sequential transducer interface module address. More specifically, the processor sends an address and command from the adapter to a specific transducer interface module  180 . The transducer interface module will then send back a calibration value for the transducer type which is connected to the module through the transducer signal conditioning circuitry. This signal is sent back to the data collection computer. The processor communicates with the transducer interface module  180  by sending a 16 bit digital address produced by flipping the polarity of the power and com lines. A diode bridge is used to create a constant dc power source for the transducer interface module even through the positive and negative lines are being flipped in their voltage polarity. External transistors Q 1  and Q 2  work in conjunction with the voltage regulator  182  internal to the transducer interface module for voltage regulation needs of the internal circuitry of the transducer interface module. The regulator will provide a 5 volt regulated voltage to the rest of the transducer interface module integrated circuitry. When the transducer interface module has been sent its address it will compare the first 8 bits of the command string to the settings on the transducer module address switch  130 . If a match occurs, it will turn on and provide power to the signal transducer circuitry and transducer coupled thereto. 
     Resistors R 3  and R 4  work as current limitors to an address receiving section of the transducer interface module to receive the command signal including the differential address being sent down the line from the processor. A crystal y 1  is connected to the oscillator within the transducer interface module which provides a clock signal for the logic in the chip. The transducer interface module takes a signal from the transducer which comes in on the xducer A and xducer B lines. When the module senses the command which is identifying a transducer signal it converts the signal which is nominally between 0.5 to 4.5 volts to a differential voltage outputted to a signal plus and a signal minus line coupled to pin  4  and pin  5  of the junctions J 1  through J 3  of the terminal block. Thus, the transducer signal is translated from a single ended signal to a differential signal. The module regulator  182 ,  184  is set by a potentiometer such that the regulator voltage is within 10 milivolts of 5 volts. The potentiometer is used as a reference for the signal conditioning circuitry. 
     Two other commands are sent to the transducer interface module  180  in the form of a low calibration signal and a high calibration signal. In this mode the transducer line that is coupled to the module is replaced with a ground line connected to ground of the module for providing the low calibration signal and then switched over to a high line for sending a 5 volt or high calibration signal. These calibration signals are stored in an output buffer which allows the buffer to have a known zero volt and a known 5 volt reference at an input to an output driver or buffer. The processor also uses these calibration voltages as references. 
     Thus, these calibration voltages allow the processor to keep track of voltages so that it can compensate for any differences in the gain of the transducer interface module drivers or any difference in the cabling caused by resistance or capacitance. Therefore, when ever a transducer interface module has data collected from it, it will receive a calibration reading signal before it receives a reading from the transducer. 
     The OK checking circuit module  220  is used to detect various things in different transducer interface modules. In the case of the accelerometer, the checking circuit means make sure the transducer&#39;s bias is at an appropriate level (for example, 2.5 volts). Thus, if any cables are cut or shorted to the transducer or if there is failure of the transducer circuitry it will detect same. 
     This detection is provided by the circuitry  220  outlined in the schematic shown if FIG. 17. A high, 5 volts, signal is outputted from the circuitry if the transducer is operating properly and a low, 0 volts, is outputted from the circuitry if the transducer is not working in the OK range. The low signal will turn off the output drivers  196  of the transducer interface module when it is in transducer mode. The processor will then determine that there is anomalies associated with the transducer or wiring interposed therebetween. 
     FIGS. 18 through 20 reflect a variation compared to that which was shown in FIGS. 9 and 10, for example. The similar part numbers will not be belabored, only the differentiating structure. As shown, the instrument package  320  replaces the transducer couplings  140  with upwardly extending posts  340  having an inner threaded bore to receive screws  342  which fix a protective cover  302  to a top surface of the previously discussed structure. The protective cover  302  houses therewithin either a thermal couple wiring harness  304  or conductors for a resistor temperature detector (RTD). The conductors  304  communicate with strip connectors  306  which allow connection to the thermal couple or RTD and an access portal  308  includes a complemental fastener  310  extending into the previously described instrument package to allow operative coupling to the circuitry mentioned earlier. A gasket  312  underlies the protective cover  302  to prevent contamination by sealing the outer periphery of the protective cover  302  which has a substantially rectangular footprint. The gasket  312  has a corresponding fenestration  314  to allow the connector  306  to mate with its complemental connector  310 . Clearance is also provided for the screws  342  to engage the posts  340 . FIG. 19 shows the underside of the protective cover  302  and depicts a further sealing gasket  318  adapted to provide a final barrier preventing contamination where the connectors  306  are located as the wires  304  pass therethrough. The gasket  318  has a generally rectangular shape complemental to the fenestration  314  and seats upon a ridge  322  complementally formed to provide good pressure between the cover  302  and its underlying support through the gaskets. A retaining chain  324  extends between the protective cover  302  and its underlying instrument package housing. In hazardous environments, the retaining chain is required as a safety measure. FIG. 18 shows the operative coupling of the connector  310  to the underlying circuit board discussed above. 
     FIG. 21 reflects a block diagram depiction of how the thermal couple (and for example RTD) device is operatively coupled. As mentioned earlier, each integrated instrument package allows two channels to communicate with transducers on the asset being monitored. Channel A and channel B are shown in FIG. 21 as receiving a signal from transducer A and transducer B in parallel whereupon a cold junction compensation instrumentality conditions the signal. Power is applied through an appropriate source as shown in FIG.  21 . Power is also supplied to the transducer interface module integrated circuits whereupon the bi-directional transfer of data extends with a bus for the discrete extraction and assessment of transducer information upon demand. FIG. 22 shows a similar setup for a dual pressure transducer hookup in which a power supply feeds a bipolar junction transistor switch which in turn drives the transducers supply signal conditioning supply and current limiting. The return signal from the transducer includes signal conditioning and verification whereupon the signal is outputted through the integrated circuit and thence to the bus as described earlier. 
     Moreover, having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.