Patent Description:
Usually field devices have field-hardened enclosures so that they can be installed outdoors in relatively rugged environments and be able to withstand climatological extremes of temperature, humidity, vibration, mechanical shock, et cetera. These devices can also typically operate on relatively low power. For example, field devices are currently available that receive all of their operating power from a known <NUM>-<NUM> mA loop.

Field devices such as process variable transmitters are used to monitor process variables associated with fluids such as slurries, liquids, vapors and gases in chemical, pulp, petroleum, gas, pharmaceutical, food, and other fluid processing plants. Process variables include, without limitation, vibration, viscosity, velocity, volume, mass, energy, pressure, temperature, flow, level, pH, conductivity, turbidity, density, concentration, chemical composition and other fluid properties. Field devices such as process actuators include control valves, pumps, heaters, agitators, coolers, solenoids, vents and other fluid controlling devices.

Some field devices communicate in accordance with a wired process communication protocol. For example, some field devices employ digital circuitry which communicates with a controller using a digital signal which is superimposed onto an analog current signal flowing through a process control current loop. One example of such a technique is the Highway Addressable Remote Transducer (HART®) communication protocol. The HART® protocol and other such protocols typically include a set of commands or instructions which can be sent to the field device to elicit a desired response, such as device control or interrogation.

Another process communication protocol is known as the FOUNDATION™ Fieldbus protocol. This protocol is directed to defining a communication layer or protocol for transmitting information on a process control loop. The Fieldbus protocol specification is ISA-S50. <NUM>-<NUM> promulgated by the Instruments Society of America in <NUM>. Another known wired process communication protocol is known as Profibus. Yet another known wired process communication protocol is known as Modbus. Additional wired process communication protocols are also known.

More recently, wireless technologies are being used to communicate with field devices. Wireless operation simplifies field device wiring and setup. One particular form of wireless process communication is set forth in IEC62591 (WirelessHART). However, it is also becoming desirable to provide field devices with additional wireless communication capabilities, such as communication in accordance with known WiFi, Bluetooth, and/or infrared (IrDA) protocols.

The environment in which a field device operates can include highly volatile or even explosive gases. Accordingly, significant requirements are demanded of such field devices to ensure that they cannot inadvertently generate a source of ignition for such environments. One way in which this safety is assured is by placing the circuitry of the field device with an explosion-proof housing. One example of an explosion-proof specification is set forth in, "<NPL>. " Compliance with an explosion-proof specification, such as that set forth above, helps ensure that even if circuitry within the field device becomes too hot or generates a spark, that ignition occurring within the field device's housing cannot escape into the larger volatile process environment. Another way in which safety of the process environment is assured is by compliance of the electronic circuitry itself with intrinsic safety requirements. One example of an intrinsic safety specification is set forth in "<NPL>. " Providing a field device that operates in accordance with an explosion-proof specification and/or an intrinsic safety specification helps ensure the safety of the process environment as well as the safety for those who interact with such field devices.

Patent publication <CIT> aims to disclose a servicing system for a field device in an automation engineering installation. The servicing system is equipped with a sensor for converting a physical variable into an electrical variable and with an actuator for converting an electrical variable into a physical variable and with a display for presenting graphical characters. A sub-region of the display outputs a two-dimensional code, the content of which is dynamic based on an operating state of the field device.

Patent publication <CIT> aims to disclose a device having an electronic circuit generating a machine-readable code and matrix code, from digital measurement data.

Patent publication <CIT> aims to disclose a display unit for a level measuring device, pressure measuring device, flow measuring device or limit level sensor with a coding unit and a display. The coding unit converts measurement data and status data of the measuring device into a two-dimensional graphic code. The graphic code can be detected by a camera of an external terminal, for example a smartphone. The coding unit recalculates the graphic code cyclically, for example at regular time intervals or when measurement data and/or status data changes.

Safety is such a concern in the process environment that in the event that technician needs to interact with components within a field device (such as to attach test leads to configure the field device or diagnose it), the act of opening the enclosure (i.e., removing the cover) may require a specific authorization (such as a hot work permit) to be obtained before such work can occur. In some instances, process control operations in the process control environment may need to be shut down prior to performing work on the field device to prevent potential electric sparks from causing an explosion in a hazardous gas atmosphere.

A field device includes a process communication module, a graphical display and a controller. The process communication module is configured to communicate in accordance with a process industry standard communication protocol. The controller is operably coupled to the process communication module and the graphical display and is configured to responsively cause the graphical display to generate a machine-readable display output.

Embodiments of the present invention generally simplify and expedite a user or technician's interaction with a field device operating in the field. When a technician is required to open the field device's housing, the process itself is relatively cumbersome and slow. In some instances, the technician may need to obtain a hot work permit. Then, the technician must open the field device's housing, attach leads, download information via a digital protocol, and then replace the cover. Even excluding the time required to obtain the hot work permit, this entire process may require many minutes. More recently it has become useful to interact with field devices that have wireless communication abilities in order to avoid the necessity for removing the cover and potential acquisition of a hot work permit. For example, <CIT> contemplates utilization of Bluetooth Low Energy (BLE) communication with a field device (shown as a valve controller). While wireless communication with field devices generally avoids the necessity of removing the cover, wireless communication itself can present other challenges. For example, some users may be sensitive to security concerns with such wireless communication.

Another difficulty with current field device interaction is that the field devices are generally relatively low-power devices and employ relatively small digital displays. For example, some current field devices employ liquid crystal displays that have a relatively low resolution and are of such size that they can only display a dozen or so human-readable words and numbers on the screen at any one time. This makes it difficult to provide a user or technician with all the information they may be looking for in a concise manner. Accordingly, current devices are somewhat limited in their ability to provide significant amounts of digital data to a user or technician at a field device in the field while still ensuring process safety and security.

Embodiments described herein generally leverage a machine-readable display output on a field device in combination with a technician or user's camera such as on a mobile device in order to quickly and securely transfer significant amounts of digital data from an operating field device to the technician's mobile device. Thus, instead of providing a dozen or so human-readable words or numbers, the device may show a machine-readable image (e.g., QR code, barcode, or another suitable image) that is acquired by the user or technician's device.

The prevalence of smart devices in process installations is increasing. These smart devices are typically equipped with a high-resolution camera capable of capturing machine-readable encoded images. Processing of these encoded images allows for faster data transfer than when using a wired connection. It is believed that time savings can be achieved due to the fact that the transfer can occur without needing to remove any of the field device's covers. This data transfer is also one-way, point-to-point. This alleviates some of the security concerns associated with current wireless options. Display of the encoded image, in one embodiment, on the field device is initiated by a local button press or other suitable techniques.

<FIG> is a diagrammatic perspective view of a field device with which embodiments of the present invention are particularly applicable. Field device <NUM> is illustrated as a process fluid pressure transmitter having a process fluid inlet <NUM> that is configured to couple to a process <NUM>. A process fluid pressure sensor is disposed within sensor body <NUM> and provides an electrical signal related to the process fluid pressure. This electrical signal is operated upon by a controller, such as a microprocessor, and converted to a process fluid pressure that may be displayed by display <NUM> and/or communicated to a remote device, such as a control room. Display <NUM> is typically a graphical display in that it has a number of elements (dots or pixels) that can be engaged to generate a display output, generally in the form of letters, numbers, or icons. Process fluid pressure transmitter has a robust enclosure <NUM> with at least one cover <NUM> that is removable in order to access the interior of field device <NUM>. Additionally, field device <NUM> may include one or more local user interface elements, such as buttons <NUM>, <NUM> that allow a user to interact with the field device. Note, field device <NUM> is simply one example of myriad different field devices with which embodiments described herein can be practiced.

<FIG> is a block diagram of a field device with which embodiments of the present invention can be practiced. Circuitry <NUM> is disposed within enclosure <NUM> and includes loop communication module <NUM>, power module <NUM>, controller <NUM>, local operator interface <NUM>, transducer interface circuitry <NUM>, and transducer <NUM>.

Process communication circuitry <NUM> is configured to communicate in accordance with a process industry communication protocol, such as the HART® protocol, FOUNDATION™ Fieldbus, or Wireless HART (IEC62591) protocol. Process communication allows field device <NUM> to report a process variable or receive a process command over a process communication loop. Process communication circuitry <NUM> is coupled to controller <NUM> to allow controller <NUM> to interact with a process controller and/or other field devices over a process communication loop or segment.

Controller <NUM> is any suitable device that is able to execute programmatic steps in order to provide its field device functions. In one example, controller <NUM> includes a microprocessor and associated memory and timing circuitry that executes programmatic steps to provide a field device output or to receive a field device command and generate a process actuator output. Controller <NUM> is coupled to local operator interface circuitry <NUM>.

Examples of local operator interface circuitry <NUM> include display <NUM>, and inputs <NUM>, <NUM>. Display <NUM> can include any suitable display technology including, without limitation, a light emitting diode display (such as an OLED display or an AMOLED display), an electro luminescent display (ELD), a liquid crystal display (LCD), a plasma display, a quantum dot (QLED display), a vacuum fluorescent display, an e-ink display, or any suitable technology capable of rendering a machine-readable image. While inputs <NUM>, <NUM> are shown as buttons, any suitable input element can be used in accordance with embodiments described herein. For example, such elements may include magnetic switches, hall switches, reed switches, capacitive touch screens, resistive touch screens, rotary encoders, photosensitive sensors, such as a photosensitive diode, acoustic sensors, or any other suitable elements capable of sensing user interaction and providing a signal indicative of such interaction to controller <NUM>.

Transducer interface circuitry <NUM> allows controller <NUM> to interact with transducer <NUM>. In an embodiment where the field device is a process variable transmitter, transducer interface circuitry <NUM> includes an analog-to-digital converter that is coupled to a transducer <NUM> in the form of a process variable sensor, such as a temperature or pressure sensor. In embodiments where the field device is a process actuator, transducer interface circuitry <NUM> may include suitable current driving circuitry to engage a transducer, such as a transducer such as a motor or valve positioner to generate valve movement.

<FIG> is a diagrammatic view of unidirectional data transfer from a field device in accordance with an embodiment of the present invention. In the illustrated example, field device <NUM> is a process variable transmitter having a display <NUM> and buttons <NUM>, <NUM>. In one embodiment, display <NUM> is disposed within housing/enclosure <NUM>, which can be explosionproof. Display <NUM> is viewable through a window in housing <NUM> such that display <NUM> can be viewed without opening housing <NUM>.

As can be seen in <FIG>, a user or technician's smartphone <NUM> is brought into proximity of field device <NUM> such that camera <NUM> of smartphone <NUM> can acquire an image of a machine-readable display output <NUM> that is presented on display <NUM>. In the illustrated example, machine-readable display output <NUM> is a two-dimensional barcode, such as a QR code. However, any suitable machine-readable image can be used. In one embodiment, process variable transmitter <NUM> is caused to generate machine-readable image <NUM> by the technician interacting with one or both of buttons <NUM>, <NUM>. However, in another example, the process variable transmitter may be caused to generate machine-readable display output <NUM> upon receipt of a suitable command via process communication.

In a claimed embodiment, where field device <NUM> includes a photosensitive diode, the field device can detect a flash of light emanating from the user's smartphone to essentially detect a flash signal as a trigger for displaying machine-readable image <NUM>. Many smart devices that have a camera are also equipped with a light source capable of providing a flash for taking pictures. This flash can be used to cause the field device to display machine-readable image <NUM>. Further, a flash signal is used to signal to the field device that the user's smart device is finished reading machine-readable image <NUM> and that field device <NUM> may display a next machine-readable image in a sequence of machine-readable images. In this way, many images could be processed by the user's smart device with no user action required to advance or otherwise control image display.

In yet another example, process variable transmitter <NUM> may be caused to generate machine-readable image <NUM> upon occurrence of an event, such as a high limit violation or a measured limit going outside of bounds, or a failure of a component within process variable transmitter <NUM>. For example, in embodiments that use e-ink displays (which generally do not need electrical power to maintain their display state) upon occurrence of a failure of process variable transmitter <NUM>, a diagnostic or troubleshooting image can be generated on display <NUM> and the display can be maintained thereon even in the event of complete power loss within the process variable transmitter.

When the user or technician's device acquires one or more images of machine-readable display output <NUM>, the smart device may automatically, or at the command of the user, process the machine-readable image(s) in order to extract data therefrom. As shown in <FIG>, an application executing on the technician's device <NUM> may provide an indication of such processing. Upon completion of the processing, the extracted data may be then shown to the technician, such as shown in the various graphs presented to the user in <FIG>. Note, a single machine-readable image may be processed to provide information on the user's device or a plurality of machine-readable images may be obtained from the field device in a sequence and processed to provide the information on the user's device.

It is believed that embodiments of the present invention will generally improve interaction with field devices in a number of different scenarios.

In a first scenario, a machine-readable display may be used to provide detailed information about the individual field device. For example, this information could include, without limitation, the field device's order code or options, thereby allowing the user to easily reorder the exact same field device or spare parts. This information could also include the state of all configuration parameters in the field device. Using machine-readable codes like this could be an alternative to existing RFID tagging technology.

In another scenario, the machine-readable information may be useful to provide an indication about the type of device. This could be helpful URLs or links to product documentation for the specific model of the field device, saving the user or technician time in looking up the information on their own.

In yet another example, the machine-readable image could provide process data history, diagnostic logs, or other large chunks of data relatively quickly. The local display is not an ideal way to show very long strings or graphs, such as can be shown in large format displays. Instead, an encoded image can be displayed that contains a history of the field device's process values and/or diagnostic/calibration logs in a specific format, which could be captured and processed by a user or technician's smart device. Finally, such data could be provided in a user-friendly manner such as a graph or table shown in <FIG>.

The above examples are merely illustrative of the improved information transfer between a field device and a user or technician's smart device via relatively limited display real estate on the field device. The encoded images described herein can take many forms. Common examples include two-dimensional barcodes or standard barcodes. These images could be shown as the only item on the screen or could be shown in addition to some human-readable text.

Additionally, embodiments described herein can be leveraged to facilitate improved security for bidirectional wireless communication between a user's device and a field device. For example, the data extracted from the machine-readable image could be required by the field device as part of a wireless communicate handshake protocol or authentication. In one example, the data encoded in the image could be a password or key that a user needs to capture with their smart device to authenticate their smart device to connect via another wireless protocol, such as WiFi or Bluetooth. Accordingly, if there is a situation where a user is concerned about security and being proximate to the field device provides sufficient security to confirm authenticity, then using an encoded image as a form of two-factor authentication would allay security concerns.

<FIG> is a flow diagram of a method of transferring data from a field device in accordance with an embodiment of the present invention. Method <NUM> begins at block <NUM> where a user or technician places a smart device having a camera into proximity of a field device display. Examples of such smart devices include a handheld field maintenance tool <NUM>. However, the technician's device may be a personal digital assistant, such as that indicated at block <NUM>, a smartphone <NUM>, or any other suitable smart device having a camera that is able to acquire an image of the display, such as indicated at block <NUM>. Once the camera is in proximity of the display of the field device, the field device caused to generate a machine-readable image on its display and the user's smart device acquires an image of the field device's display, as indicated at block <NUM>.

Once the image has been acquired, it is processed, at block <NUM>, in accordance with suitable known image processing techniques in order to extract the encoded data from the machine-readable image. Next, at optional block <NUM>, the extracted information may be supplemented using the extract information itself. For example, such supplementation can include the user or technician's device using an extracted URL to obtain information from the internet, <NUM>. In another example, extracted information about the field device can be used to reference a device description (DD) of the field device, as indicated at block <NUM>.

Additionally, any other suitable source of information can be used to supplement the information based on the extracted information as indicated at block <NUM>. Finally, at block <NUM> the extracted data as well as any suitable supplementation data is displayed to the user on the user's smart device. An example of such display is shown above with respect to <FIG>.

<FIG> is a flow diagram of a method of establishing bidirectional wireless communication with a wireless field device in accordance with an embodiment of the present invention. Method <NUM> begins at block <NUM> where a field device provides a machine-readable image on its display and a user or technician's smart device acquires an image thereof. The machine-readable image can be that in accordance with any of the examples set forth above. Next, at block <NUM>, the user or technician's smart device extracts data from the machine-readable image in accordance with a suitable data extraction technique for the particular machine-readable image technology used. Next, at block <NUM>, the extracted data is used to initiate bidirectional wireless communication with the field device. Any suitable bidirectional wireless communication protocol can be used. Examples include wireless fidelity (WiFi) <NUM>, Bluetooth, such as Bluetooth Low Energy <NUM>, WirelessHART <NUM>, or any other suitable wireless communication technology now known or later developed, as indicated at block <NUM>.

Claim 1:
A field device (<NUM>, <NUM>) comprising:
a process communication module (<NUM>) configured to communicate in accordance with a process industry standard communication protocol;
a graphical display (<NUM>, <NUM>); and
a controller (<NUM>) operably coupled to process communication module (<NUM>) and the graphical display (<NUM>, <NUM>), the controller being configured to responsively cause the graphical display (<NUM>, <NUM>) to generate a machine-readable display output (<NUM>);
wherein the controller (<NUM>) is configured to cause the graphical display (<NUM>, <NUM>) to generate a series of machine-readable display outputs (<NUM>);
characterized in that the field device is configured to display a next machine-readable image in a sequence of machine-readable images based on a photosensitive diode detecting a flash of light.