Abstract:
Field devices, including sensors and final elements, are provided with a speech synthesizer and optionally a speech control chip, to sound audible voice maintenance and fault alarms to alert field personnel and, optionally, a voice message upon manual activation of a pushbutton or other switch directing them how to perform the maintenance task or clear the fault.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to the integration of audible status reports into field instrumentation and control devices, including sensors and final elements, such as smart emergency shut-off valves and control valves. 
         [0003]    2. Description of Related Art 
         [0004]    Large industrial facilities such as oil collection plants and refineries, water and wastewater treatment plants, electric utilities and manufacturing plants can include hundreds or thousands of field devices. Field devices include sensors and final elements. Sensors can include pressure, temperature, level and flow measuring sensors and their associated transmitters, position and limit switches, vibration monitors, and other process instruments. Final elements can include electric solenoids, pneumatic actuators and positioners for controlling the starting, stopping and the speed of motors, the opening and closing of valves either fully or to a predetermined position, and heaters and heat exchangers. Field devices are typically connected to a plant-wide central monitoring computer-based system, so that remote field processes can be monitored and controlled from a centralized control location. 
         [0005]    In the late 1980s, instrument manufacturers began to embed microprocessors in their field devices which allowed the user to receive diagnostic alarms. However, these diagnostic alarms were only available to operators at the centralized control location. Recent advances in microcomputers and networking have led to advancements in field devices so that they not only permit instrumentation and control to be monitored and directed from a central control location, but they also permit monitoring and control in the field. These advancements providing for control in the field have led to enhanced field monitoring of the health of the field devices themselves. That is, the diagnostic alarms are not only available to operators at the central control location, but also the personnel in the vicinity of the device. 
         [0006]    It is known to provide field devices with lights and/or audible alarms that are actuated when a problem with the device has been detected during routine operation or a self-diagnostic check, such as a partial stroke test of valves and valve actuators. See, for example, U.S. Pat. No. 7,504,961, “Emergency Isolation Valve Controller with Integral Fault Indicator” (Flanders, assigned to Saudi Arabian Oil Co.), and U.S. Pat. No. 8,072,343, “Local Emergency Isolation Valve Controller with Diagnostic Testing and Trouble Indicator,” both of which are incorporated by reference. Of course, the purpose of such visible and audible alarms is to attract the attention of personnel in their vicinity. Personnel cannot determine the nature of the problem that caused the alarm to be actuated until they proceed to the local control panel on the device and manually engage the device, e.g., by connecting a portable computer, pad or other smart device to download information, or by pressing a pushbutton type switch to view a display on the device. 
         [0007]    As was noted above, a petrochemical or refining facility can contain many thousands of devices that are equipped with these alarm features. It has been found that personnel engaged in other activities in the field who become aware of visible and/or sounding alarms emitted by devices for which they have not then been dispatched to repair or check will not consistently undertake to approach the device to investigate and determine the nature of the problem. If the personnel in the vicinity of the device has not been assigned the task of checking for alarms, there can be a general tendency for such individuals to go about their assigned tasks, based on the assumption that the problem is not significant and/or that others will eventually come to check the device. This lack of knowledge of the reason for the alarm and the associated human response, is a problem that has not been addressed by the prior art. 
         [0008]    This is problematic, because a field technician might pass by a field device that is reporting a significant fault without recognizing it, only to learn later from a control room operator of the problem. Likewise, a significant benefit of having control in the field capabilities is to provide for redundancies in the event of a loss in communication between the field and the control room. If this communication is lost, the control room will be unaware of a fault in a field device. 
         [0009]    For example, referring to  FIG. 1 , a prior art embodiment of a warning system  100  for field devices is illustrated. Field devices  110  are located in Tier  3 , a CMMS server  120  is located within a control network in Tier  2 , and a CMMS client  130  is located within the plant-wide network in Tier  1 . Field devices  110  incorporate a microprocessor  112  that provides an instrumentation and control function. For example, if the field device is a sensor, the microprocessor  112  monitors the parameters being monitored by the sensor, for example temperature, pressure, or limit switch status. These monitored parameters are fed to a network  115  which transmits the parameters from field device  110  in Tier  3  to CMMS server  120  in Tier  2 , which in turn communicates via network  125  to CMMS client  130  in Tier  1 . If the field device is a final element such as a valve controller, the microprocessor  112  provides a control function, such as receiving a signal to close the associated valve. This signal is typically initiated at CMMS client  130  in Tier  1 , is transmitted to CMMS server  120  in Tier  2 , and then is transmitted to the microprocessor  112  in field device  110  in Tier  3 . 
         [0010]    In addition to microprocessor  112  performing these instrumentation and control functions, microprocessor  112  monitors the health of the field device. If field device  110  requires maintenance or repair, microprocessor  112  communicates this information upstream to CMMS client  130 , via network  115 , CMMS server  120 , and network  125 . An operator  140  assigned to monitor CMMS client  130  receives the message that field device  110  requires maintenance or repair. The maintenance or repair function is conducted by field personnel  150 . Operator  140  communicates the maintenance or repair message to field personnel  150  via communications path  145 . Depending upon the distance between operator  140  and field personnel  150 , and the availability of cellular telephone coverage or radio coverage, this message could be delayed. Similarly, in the event of a malfunction of CMMS server  120 , CMMS client  130 , or networks  115  or  125 , the maintenance or repair message from microprocessor  112  of field device  110  might be delayed or even prevented from reaching operator  140 , and thus would not be relayed to field personnel  150 . These shortcomings are representative of a problem with the prior art systems. 
         [0011]    It is therefore an object of the present invention to provide a solution whereby field devices can provide audible status reports so that field personnel working in the vicinity can recognize that a field device requires maintenance or repair. Another object of the present invention is that the status reports can guide the field personnel in maintaining or repairing the field device. 
       SUMMARY OF THE INVENTION 
       [0012]    The above objects and further advantages are provided by the invention that integrates audible aural or spoken messages in the form of status warnings device alerts (i.e., status reports) into field devices. 
         [0013]    In accordance with one aspect of the present invention, a field device includes a system that integrates a microprocessor with indicating lights, a speaker, one or more pushbuttons, and associated control circuitry in order to provide field personnel in the vicinity of the device with both an audio and visual indication of the health of such devices. A voice synthesizer and/or memory device with pre-recorded messages corresponding to predetermined faults or defects for which the device is tested is provided. 
         [0014]    For example, in one embodiment, an operator field service or maintenance personnel sees an illuminated indicator light on the field device, signaling that the device has a message for personnel. The field device could have a number of indicator lights of different colors, for example traditional low-voltage incandescent bulbs with colored caps, a single indicator light with illumination provided by one of a number of LEDs. For example, a green light would indicate that an advisory-type of message is available, a yellow light would indicate that a maintenance alarm is present, and a red light would indicate that there is a serious problem requiring immediate attention. Upon approaching the device, the operator presses a pushbutton to receive an aural message. For example, the operator presses a first pushbutton and the device announces, “Air supply low.” In an alternative embodiment, there is a second pushbutton to provide additional guidance, for example, “Check air supply and increase to 40 PSI.” 
         [0015]    In a further embodiment, the field device repeatedly announces aural maintenance alarms or serious problems at regular intervals, without requiring an operator to first press a pushbutton. This embodiment functions to draw the attention of a passing field employee who had not noticed that the indicator light is illuminated. 
         [0016]    In one embodiment, the audible announcements can be a human voice that is recorded, for example, as a WAV file stored in the memory of the final device&#39;s microprocessor. In another embodiment, the audible announcements can be generated by a digital text-to-speech synthesizer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The invention will be described in further detail below and with reference to the attached drawings in which the same or similar elements are referred to by the same numerals, and where: 
           [0018]      FIG. 1  is a block diagram of a prior art warning system for field devices; 
           [0019]      FIG. 2  is a block diagram of a warning system for field devices in accordance with an embodiment of the present invention; and 
           [0020]      FIG. 3  is a block diagram of several components of a field device incorporating an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The present invention broadly comprehends an enhanced warning system for field devices that incorporates means for issuing aural status reports to enable field devices, empowering field personnel to respond more quickly to maintenance and repair messages. 
         [0022]    Referring to  FIG. 2 , an embodiment of the present invention, a warning system  200  for field devices that produces audible aural status reports is illustrated. Field devices  210  are located in Tier  3 , a CMMS server  220  is located within a control network in Tier  2 , and a CMMS client  230  is located within the plant-wide network in Tier  1 . Field devices  210  incorporate a microprocessor  212  that provides an instrumentation and control function. Monitored parameters are fed to a network  215  which transmit the parameters from field device  210  in Tier  3  to CMMS server  220  in Tier  2 , which in turn communicates via network  225  to CMMS client  230  in Tier  1 . If the field device is a final element, such as a valve controller, the microprocessor  212  provides a control function, such as receiving a signal to close the associated valve. This signal is typically initiated at CMMS client  230  in Tier  1 , is transmitted to CMMS server  220  in Tier  2 , and then transmitted to microprocessor  212  in field device  210  in Tier  3 . 
         [0023]    In addition to microprocessor  212  performing these instrumentation and control functions, microprocessor  212  monitors the health of the field device. If field device  210  requires maintenance or repair, microprocessor  212  communicates this information in two ways. Firstly, as with the prior art, microprocessor  212  communicates the maintenance or repair message upstream to CMMS client  230 , via network  215 , CMMS server  220 , and network  225 , where it must come first to the attention of operator  240  before any action is taken. Secondly, field devices  210  are provided with a speaker and control circuitry  213  through which microprocessor  212  outputs a signal, which in turn produces an audible signal  214  intended to draw the attention of any field personnel  250  in the area. Ordinarily, the prior art practice of operator  240  communicating the maintenance or repair method to field personnel  250  via communications path  245  will also be available. Thus, the invention allows field personnel  250  to learn of a maintenance or repair message directly and immediately from field device  210 , if the field personnel  250  are in the vicinity. The invention also allows them to check the status of field device  210  in the field in the event of a malfunction of CMMS server  220 , CMMS client  230 , or networks  215  or  225 . If field personnel  250  are not in the vicinity of field device  210  and there is no malfunction of CMMS server  220 , CMMS client  230 , or networks  215  or  225 , then operator  240  can communicate the maintenance or repair message to field personnel  250 , as in the prior art. 
         [0024]    As can be seen, the addition of audible signal capabilities to the field devices provides a redundant path for alerting field personnel of maintenance or repair actions that are required. 
         [0025]      FIG. 3  illustrates a block diagram of several components of a typical field device incorporating an embodiment of the present invention. Field device  300  includes an enclosure  305 , processor  310 , sensors (not shown), a memory  340 , an analog-to-digital (A/D) converter  315  and a digital-to-analog (D/A) converter  320 . Memory  340  and diagnostic data buffer  345  are utilized to store a variety of information. A/D converter  315  converts the inputs from one or more sensors from analog to digital format and transfers the corresponding digital signals to processor  310 . D/A converter  320  can convert a plurality of outputs from the control network to the field device and is especially useful for final elements. For example, if field device  300  is a digital valve controller, D/A converter  320  can convert a digital command received from the control network to an analog signal that drives a valve actuator to close predetermined percentages, e.g., 50%, or until a predetermined desired flow rate or pressure is achieved. 
         [0026]    Field device  300  further includes clock  380  and communication unit  325 . Data can be transferred over the control network, or alternatively can be transferred with a portable communications device through communication unit  325 . 
         [0027]    Speech synthesizer  330  is a voice and sound synthesizer. Inexpensive speech synthesizers are commercially available and their use in the present invention is within the skill in the art. The Magnevation SpeakJet is preprogrammed with 72 speech elements (allophones). Software to program a speech synthesizer in plain-text as opposed to allophones can be incorporated into processor  310 , or alternatively the function can be provided as a separate speech control chip  335 . Speech control chips are also commercially available. The Magnevation TTS256, which has a built-in  600  rule database to convert English text to allophones can be incorporated in the field devices and actuated by the microprocessor. 
         [0028]    Speaker  370  and amplifier  365  provide speech and/or sound to draw the attention of field personnel, and to provide directions to field personnel to identify the problem and its resolution. Power supply  375  provides power to amplifier  365 . 
         [0029]    In an alternate embodiment, speaker  370  and amplifier  365  only provide speech and/or sound to draw the attention of field personnel if a motion sensor (not shown) detects field personnel and/or vehicles in a predetermined range of proximity to the device. 
         [0030]    In addition to the audible alarm, the field device can also be provided with visible alarms, such as indicator lights of different colors (not shown). For example, a green light can indicate that an advisory-type of message is available, a yellow light that a maintenance alarm is present, and a red light that there is a serious problem requiring immediate attention. 
         [0031]    Display  350  is typically an LCD screen that can, for example, in the case of a field device that is a sensor, provide a digital readout of pressure, temperature, or other parameter. Display  350  can also be used to provide control instructions, and to provide maintenance and repair messages to field personnel. 
         [0032]    In one embodiment of the invention, there are two pushbuttons,  355  and  360 . In the event of a malfunction, an alarm routine  385  stored in memory  340  adapted to be executed in processor  310  calls for an audible signal to be sounded by speech synthesizer  330 , amplifier  365  and speaker  370 . This can be a continuous or variable tone, or a recorded sound or voice such as from a WAV file. In an alternative embodiment, alarm routine  385  calls for text to be sent to speech control chip  335 , which converts the text into allophones to be processed by speech synthesizer  330  and passed through amplifier  365  and speaker  370 . In yet another alternative embodiment, alarm routine  385  calls for text to be sounded, with alarm routine  385  including a subroutine (or by activating a separate routine) that converts the text into allophones, the allophones being sent directly to speech synthesizer  330 , thereby obviating the need for speech control chip  335 . 
         [0033]    Field personnel hearing a sounded alarm approach field device  300  and press the first pushbutton  355 , upon which a status routine  390  stored in memory  340  adapted to be executed in processor  310  calls for a spoken status (e.g., “air supply low”) to be sounded by speech synthesizer  330 , amplifier  365  and speaker  370 . Status routine  390  can include a subroutine (or activate a separate routine) that converts the desired text into allophones to be sent to speech synthesizer  330 , or alternatively status routine  390  can send text to a separate speech control chip  335 , which then sends allophones to speech synthesizer  330 . 
         [0034]    The field personnel then presses the second pushbutton  360 , upon which an instructional routine  395  stored in memory  340  adapted to be executed in processor  310  calls for a spoken instruction, e.g. “check air supply and increase to 40 PSI”, to be sounded by speech synthesizer  330 , amplifier  365  and speaker  370 . Instructional routine  395  can include a subroutine (or activate a separate routine) that converts the desired text into allophones that are sent to speech synthesizer  330 , or alternatively instructional routine  395  sends a text to a separate speech control chip  335 , which then sends allophones to speech synthesizer  330 . Thus, the invention not only serves the purpose of informing field personnel of maintenance or failures, but also serves to educate them in performing the maintenance or clearing the fault. One of ordinary skill in the art would recognize that in lieu of two pushbuttons, a single pushbutton would suffice, for example by being pressed twice in succession. 
         [0035]    The present invention has been described above and with reference to the attached drawings; however, modifications will be apparent to those of ordinary skill in the art and the scope of protection for the invention is to be defined by the claims that follow.