FIELD OF THE INVENTION AND USE OF INVENTION

[0001] The invention generally relates to the field of control systems and more specifically to field devices, and provides a method and system to increase the processing capability of the field devices deployed in an industrial plant.

PRIOR ART AND PROBLEM TO BE SOLVED

[0002] Industrial Control System is typically used in process industries such as refinery, oil and gas, paper and pulp, manufacturing and the like. It is a specially designed control system to control industrial process in industrial plants including complex, large and geographically industrial processes. Typically, in the Control System, field devices such as sensors and actuators measure process parameters like temperature and pressure, and controls the valve by changing its position, are connected to input and output devices, which in turn communicate with controller modules through a communication bus for data monitoring, data logging, alarming and controlling purpose.

[0003] The communication protocols used in the Control System are of different types such as foundation field bus, HART® (highway Addressable Remote Transducer Protocol), PROFIBUS® (Process fieldbus), Modbus (serial communication protocol) and use a native network of the Control System.

[0004] The hardware resources for the field devices broadly include, communication, processing/analysis/control, and sensing/actuating hardware. Communication related hardware handles the protocol specific communication. Processing/analysis/control related hardware handles the raw sensing data processing tasks. And, the sensor related hardware performs the signal sensing task.

[0005] Present day field devices are built with more intelligence for data processing and analysis by addition of hardware resources that perform sensor data processing, analysis and enable the protocol specific communication. However, while the capabilities of the field devices have been enhanced, addition of these hardware resources has also increased manufacturing cost, as well as life-cycle maintenance cost of these field devices. [0006] Further, to handle new complex tasks, the existing field devices need to be upgraded often. Still further, if such a field device is damaged, the replacement of damaged device with new device has to be done... Replacement involves various steps to resume functionality of old field device by new field device. Such shortcomings, in turn lead to additional operational costs of the plants and control and monitoring operations.

OBJECTS OF THE INVENTION

[0007] There is a need to find an alternate technical solution that substitutes the complexity of adding of processing hardware on the field devices.

[0008] It is an object of the invention to address the above need by providing a method and system for increasing the processing capability of the field devices without adding additional hardware resources. This is achieved by using a processing sub-system hosted on a network transparent to the Control System. This allows the processing and analysis part of field data to be performed on a separate entity. For example, the separate entity can reside on a remote service server, cloud, or web server. This not only reduces the hardware burden on the field devices, it further allows for sharing of processing and analysis functionalities among the field devices.

SUMMARY OF THE INVENTION

[0009] In one aspect, an industrial control system for control and monitoring of one or more process conditions in an industrial plant is provided. The industrial control system includes one or more field devices, one or more input-output devices, at least one controller, and at least one server. A processing sub-system is provided for scaling processing capability of a field device in the industrial control system, wherein the processing sub-system includes a functional component library module having a plurality of functional components. A virtual field device object is configured using one or more functional components from the plurality of functional components, and a field device identifier tag of a field device in the industrial control system. The processing sub-system includes a communication module for receiving measurement data from the field device. The functional components are configured for processing the measurement data to generate processed field device data, and the communication module is configured for communicating the processed field device data. The control system includes one or more pre-configured communication interfaces to communicate the processed field device data to the industrial control system.

[0010] In another aspect, a method for scaling processing capability of a field device in an industrial control system using a processing sub-system is disclosed. The industrial control system includes one or more field devices, one or more input-output devices, at least one controller, and at least one server. The method includes a step for configuring a virtual field device object in the processing sub-system using one or more functional components from a plurality of functional components, and a field device identifier tag of a field device in the industrial control system. The method further includes receiving measurement data from the field device in the processing sub-system; and processing the measurement data in the processing sub-system by the virtual field device object corresponding to the field device, to generate processed field device data. The method then includes a step for communicating the processed field device data using one or more pre-configured communication interfaces to the industrial control system.

DRAWINGS

[0011] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like reference numerals represent corresponding parts throughout the drawings, wherein:

[0012] FIG. 1 is a diagrammatic representation of an exemplary control system for control and monitoring of one or more process conditions;

[0013] FIG. 2 is a diagrammatic representation of one embodiment of system of FIG. 1 with a coupler to receive measurement data from the field devices and communicate the measurement data to distinct virtual field device objects in the processing sub-system;

[0014] FIG. 3 is a diagrammatic representation of another embodiment of system of FIG. 1 with a coupler to receive measurement data from the field devices and communicate the measurement data to one virtual field device object in the processing sub-system;

[0015] FIG. 4 is a diagrammatic representation of an exemplary implementation showing the communication interface between the field device and the processing sub-system; [0016] FIG. 5 is a diagrammatic representation of another exemplary implementation showing the communication interface between the field device and the processing subsystem;

[0017] FIG. 6 is a diagrammatic representation of a prior art intelligent field device with the different data layers;

[0018] FIG. 7 is a diagrammatic representation of field device data layer with using the processing sub-system of the invention;

[0019] FIG. 8 is a block for a prior art field device with the hardware modules for advance processing and analytics;

[0020] FIG. 9 is a block diagram for an exemplary field device that is used with the processing sub-system, according to an embodiment of the invention; and

[0021] FIG. 10 is a flowchart showing exemplary steps for the method for scaling processing capability of a field device according to an aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022] As used herein and in the claims, the singular forms "a," "an," and "the" include the plural reference unless the context clearly indicates otherwise.

[0023] FIG. 1 is a diagrammatic representation of an exemplary industrial control system 10 for control and monitoring of a process, according to one aspect of the invention. The industrial control system 10 includes field devices 14, input-output (IO) devices 16, at least one controller 18, and at least one server 20. The control system 10 further includes a server or processing sub-system 22 for scaling processing capability of a field device 14 in the industrial control system 10. The field devices referred herein are physical on- field hardware devices which are located on in the actual process plant. The processing sub - system advantageously allows for creating off-field or virtual field devices that use measurement data from on-field devices and do desired processing separately thus removing the processing burden and also rigid electronic configurations otherwise needed from the on- field devices. The processing sub-system is explained in more detail below. [0024] The processing sub-system 22 includes a functional component library module 24 having different functional components, represented as Functional Component 1, 2...n in FIG. 1. Each functional component represents rules and logic with respect to the functionality of the functional component. The functional component library module may be in-built in the processing sub-system or may be provided externally on a separate device that is accessible by the processing sub- system. For example, one functional component would contain the logic needed for sensor linearization.

[0025] In the processing sub-system, a virtual field device object 26 is configured using required functional components (Functional Component 1 in FIG. 1), and a field device identifier tag of a field device 14 in the industrial control system 10. This ensures process control integrity, as the field device measurement data is always identifiable, and further processing includes the identity of the field device and therefore the identity of the particular process condition being controller and monitored. As mentioned herein above, the functional components in the virtual field device object, process the measurement data as per the functionality, rules, and logic embedded in the functional component, to generate processed field device data. Thus when a deployed field device does not have a particular processing capability in-built through the hardware resources on the field device, the processing can be accomplished using the virtual field device object. This enhances the capability of existing device without having to upgrade the hardware of the existing device.

[0026] The processing sub-system 22 includes a communication module 28for receiving measurement data (shown as MD in FIG. 1) from the field device. The communication module may be integrated with the virtual field device object, or may be provided as a separate module or may be integrated with the processing sub-system. The communication module 28 is also used for communicating the processed field device data after the processing via the virtual field device object.

[0027] In one example, the field device 14 is equipped with a communication interface represented as "CI", it could be for example, a wireless interface, for example a low power wifi, Bluetooth interface etc. In one exemplary implementation "CI" transfers measurement data directly to the virtual field device object 26 with an identity (i.e. a unique identity 'ID') for the field device via the communication module 28. In this case, the measurement data that is initially received as an analog signal by the field device is converted to digital data in the field device itself.

[0028] In one exemplary embodiment, the communication module is provided as a separate module, it may be provided as a coupler 30 as shown in FIG. 2, the coupler 30 is configured as a hardware device or a software module to receive measurement data from one or more field devices (shown as Field Device 1, 2, 3 in FIG. 2) in separate communication channels, and transmit the measurement data (shown as MD1, MD2, MD3) by tagging it with the field device identity. In one exemplary implementation tagging is done using a unique field device identifier tag.

[0029] In an alternate embodiment, as shown in FIG. 3, the coupler 30 can be configured as a data aggregator device, and multiple field devices are connected to the data aggregator (DA) device. The DA device converts the field device analog output to digital data using ADC (analog to digital converter). Then, it tags the data with their field device unique ID. Further, it aggregates all the sensor data and sends it to the processing sub-system (virtual field device object, indicated by reference numeral 26*) via wired or wireless medium.

[0030] It would be appreciated by those skilled in the art that the aggregator device of FIG. 3 can communicate the field device data from different field devices in several ways. For example, the aggregator device can communicate field device data from each of the field device with their respective unique IDs. In another example, the aggregator includes an intermediate processor to perform specific processing and send the resultant of the processing to the processing sub-system. For e.g. one of the field device data may be sending measurements related to "volume" of fluid, and the other field device data may be sending the measurements related to "velocity" of the fluid, and these measurements may be time synchronized so that they relate to same measurement instance. The aggregator may include an intermediate processor to calculate the "flow rate" based on the "volume" and velocity" measurements, and communicate the flow rate measurement data to the processing subsystem along with the unique IDs of both the field devices. There may be other combinations to aggregate the field device data, based on the real world requirement. However, it may be noted here, that even when the aggregator does not have any intermediate processor, a desired functional component can be created in the processing subsystem itself. [0031] It would be understood by those skilled in the art that the control system includes one or more pre-configured communication interfaces to communicate the processed field device data to the industrial control system. These pre-configured communication interfaces link a native network of the industrial control system with a second network of the processing subsystem, wherein the second network is different from the native network. The pre-configured communication interfaces are provided via the communication module and communicate the processed field device data to at least one of the field device, an input-output device coupled to the field device, the at least one controller and the server

[0032] The FIG. 4 shows the one of the deploying option where field device has two interfaces. One interface for communicating with the processing sub- system and another interface for communicating with typical IO (Input-Output) device. Interface 1 as shown in FIG. 4 is used for traditional IO communication for communicating sensing and processing task requests. Task requests would be understood by those skilled in the art as instructions from IO devices to receive specific information or to provide specific information. The IO interface to enable communication can implement known DCS protocols such as HART® protocol, PROFIBUS®, or any other DCS native network communication protocol. Interface 2 is used for enhancing field device capability by enabling the physical field device to connect to the processing sub-system. The connection between Interface 2 and processing sub-system can be wired or wireless. As explained herein above, based on the processing task request, the field device processing power can be enhanced by adding functional components in the virtual field device object. For upper layer entities such as IO device, controller and server, receiving the processed field device data will be seamless via the field device.

[0033] Another scenario of deployment is shown in FIG 5, where the field device has only one interface, interface 3 to communicate the measurement data to processing sub-system. The interface 3 could be wired or wireless. The processing sub-system accesses measurement data from the field device via interface 3 and performs the complex processing required by the application as provided by the customer to generate processed field data. Communication of processed field data from the processing sub-system, is enabled as follows in this exemplary embodiment. A coupler is used to receive the processed field data via interface 4 and converts the processed field device data received from the processing subsystem into protocol specific format like HART®, PROFIBUS® etc., and communicates this processed field device data via interface 5 to 10 device. One coupler can be used to represent multiple field devices using IO channels as mentioned before. Each of the IO channels of the coupler can be configured for HART®/ PROFIB US ©/Foundation Fieldbus® etc. protocols. For any of the upper layer entities such as IO devices, controller and server the communicating with the coupler is same as communicating with the field device.

[0034] FIG. 6 and FIG. 7 illustrate the impact of external processing sub-system on the field device data protocols. FIG. 6 illustrates a prior art intelligent field device with the different data layers 40 for different processing tasks. FIG. 7 shows that through the present invention, the field device data 42 is considerably reduced as the processing layers are shifted to the processing sub-system, and are no longer required to be present on the field device. Similarly, FIG. 8 illustrates a block diagram 44for a prior art field device with all the hardware modules for advance processing and analytics, and FIG. 9 illustrates a block diagram 46for an exemplary field device that is used with the processing sub-system, according to an embodiment of the invention.

[0035] Some exemplary use cases are described herein below that further illustrate the different embodiments of the invention:

[0036] Case-1: Full fledge field device with IO and Virtual field device Object (VF) connectivity:

Full fledge field device refers to a field device which can be operated alone. The prior art field devices can be considered as full fledge device. These have sensing, processing and communication capabilities built into the field device. Adding the processing sub-system of the invention to full fledge device enhances the device capabilities, while ensuring basic processing within the field device itself. Field device can have inbuilt VF interface or it can use external VF adaptor/coupler component to connect with VF. In this scenario, field device process basic requests from IO device by its own and it forwards complex processing requests to VF.

[0037] Case 2: Dumb field device with IO and VF connectivity:

Dumb devices are those field devices which do not have processing capability built into the field device. For example, 4-20mA temperature device, which only measures the temperature and generates the output in the form of 4-20mA current. It does not have capability to say whether measured value in Centigrade or Fahrenheit. The complete processing activity is carried out in the processing sub-system of the invention. All the requests (or commands) which come to dumb field device from 10 devices or any higher entity like controllers, are forwarded to the processing sub-system for processing and response from processing sub- system are received by the dumb field device and sent back to IO devices or controllers.

[0038] Case-3: Dumb field device only VF connectivity:

In this scenario, the dumb field device has only interface with the processing sub-system. Dumb field device sends measurement data to the processing sub-system, and rest of the processing logics are executed in the processing sub-system. IO device, controller or server can access the processed field device data directly from processing sub-system. This scenario is suited for remote monitoring kind of application.

[0039] Case 4: Field device and Processing sub-system communication:

This example shows the traditional communication between Controller/Server via an Application (coded instructions for particular process tasks), IO device, field device and processing sub-system. Assume that the Application want to read minimum temperature value from last six month. For this, the Application sends a request to IO device and IO device sends the request to a field device that is monitoring temperature. This particular field device's memory is not enough to store six months data so it is incapable to process this request, and the field device therefore forwards this request to the processing sub-system.

The field device, in this implementation, is in communication with the processing sub-system through a communication interface. The virtual field device object in the processing subsystem is reading and storing (the functional component in this case is "Read and Store") field device measurement data periodically and it has field device historian data. The processing sub-system receives the field device request to report minimum temperature from last six months the application request and return the response to the field device. After receiving the response from VF, the field device responds back to IO and then to Application at controller or server level. In this scenario, the interaction between physical field device and VF in the processing sub-system is completely isolated from the Application. It would be understood by those skilled in the art that the communication between VF and field device can be asynchronous or synchronous communication.

[0040] Case 5: Controller/Server direct communication with the Processing sub-system:

In another exemplary implement, since the processing sub-system has all field device measurement data, the Application at Controller/Server can directly interact with the processing sub-system to get the processed field device data. There is no need of IO device and associated hierarchical devices to read field device data. The processing sub-system in this case asynchronously reads the field device measurement data and performs the processing in background. When the processing sub-system gets the request from Application, it responds to the Application with the processed field device data that is sent directly to controller/server. A virtual field bus may be used in an exemplary embodiment for connecting and sharing information between field device objects, and external controller/server.

[0041] The processing sub-system as described herein is implemented in an exemplary embodiment as a software application residing to the external device, such as a cloud, remote or web server, and is connected with field device via wireless or wired medium. The processing sub-system continuously accesses the field device measurement data based using the virtual field device object. Based on the demand set by the application, processing subsystem performs complex processing, analysis and control task and returns back the result as processed field device data to the same field device, or elsewhere as per the communication interface and communication protocol as explained in several use case herein above. The execution of processing tasks separately and external to the field device as enabled by the invention, gives flexibility to execute any kind of complex processing since virtually unlimited resources are available.

[0042] The technique mentioned herein allows customized processing of field data by enabling or disabling or selecting functional components on demand, re-use of functional components, thus adding processing capabilities and flexibility. On top of basic libraries set for the functional components, new libraries can be added for providing new functional components in the processing sub-system, for example for dynamic process trend diagnostics and such other analytics demand. [0043] Another aspect the invention described herein, is a method for scaling processing capability of a field device in an industrial control system. The method is illustrated in flowchart 50 of FIG. 10. This is achieved by using the processing sub-system external to the field device hardware, as explained in reference to the FIG. 1-5 above. The method includes a step 52 for configuring a virtual field device object in the processing sub-system using necessary functional components, and a field device identifier tag of a particular field device in the industrial control system. The functional components are provided through a library of pre-configured functional components in the processing sub-system, or may be provided in dynamic manner, on-the-fly based i.e. need based on the requirement received from an operator station. The ability to select functional components external to the field device, allows great flexibility and scaling of processing capability of any given field device.

[0044] For example, functional components of 'pressure linearization', and 'historian', may be selected in one embodiment. In another embodiment a functional component of 'asset management' may be added. In yet another embodiment, a functional component "Alarm and Event" may be added. Other functional components include but are not limited to "Security", "Calibration", "PROFIBUS® Communication", "Foundational Fieldbus Communication" etc. Each functional component has rules and logic to obtain the processed output, which is referred herein as processed field device data relating to that functionality.

[0045] For generating processed field device data, the method includes a step 54 for receiving measurement data from the field device in the processing sub-system, processing the measurement data in the processing sub-system as shown at step 56 by the virtual field device object corresponding to the field device. The method then includes a step 58 for communicating the processed field device data using one or more pre-configured communication interfaces to the industrial control system for use in control and monitoring function.

[0046] It would be appreciated by those skilled in the art, that not only the processing capability of field device is easily scalable using the method described herein, different communication interfaces can be provided to communicate the processed field device data to suit the plant and customer requirement.

[0047] Based on the communication interface, a suitable communication protocol is selected to communicate the processed field device data. The format for processed field device data is flexible as explained earlier. It can be converted into any protocol application layer data format such as, HART®, PROFIBUS® or Profinet packet suited to consumer.

[0048] The different configurations for communication interfaces implemented by the method of the invention, include a communication interface for communicating the processed field device data to the same field device from which the measurement data was received. In another embodiment, the communication interface is provided to communicate the processed field device data to an input-output device coupled to the field device from which the measurement data was received. In another embodiment, the communication interface is provided to communicate the processed field device data to the at least one controller. In another embodiment, the communication interface is provided to communicate the processed field device data to the server. These configurations have been explained in relation to the control system of the invention.

[0049] These pre-configured communication interfaces are configured to receive at least one of request commands, input-output commands, and control commands from at least one the field device, an input-output device coupled to the field device, the at least one controller, the server, and the operator station. The one or more pre-configured communication interfaces use at least one of wired or wireless communication means.

[0050] The consumers of processed field device data include controller, IO device, asset monitoring application and other customer requirement based applications operated at the controller or server level. Since the processed field device data now resides on an external network such as the cloud network (public/private), the processed field device data can be access processed directly from the cloud by providing the necessary communication configuration.

[0051] The proposed solution provides great level of flexibility, to offer customer specific products. With same dump physical device, various customized virtual field device objects can be offered to customer. Based on application demand, customer can avail the enhanced features of device.

[0052] Since the processing/analysis specific hardware resource is now de-coupled from the field device, the manufacturing cost decreases significantly. In addition, for the future product the existing manufacturing line can be reused. [0053] Enabling virtual field device object using the processing sub-system provides unlimited processing capabilities to the physical field device. Now the processing subsystem is capable for performing data analytics, data processing, and complex control activity specific to customer needs, and on demand, device capability can be enhanced. Depending on the need, compute/process and amount of data processing could vary dynamically and transparently. Data can be stored for longer period and made available even if there is any issue with the DCS system. Unlike remote service, this solution provides two way communication with DCS.

[0054] Since the processing power any field device can be increased/decreased dynamically on the fly it gives opportunity to device vendor to offer various kind of service options to the customer. Further, without changing/upgrading of physical device new capabilities to device can be added. The processing sub-system can be customized based on application requirements provided by the customer and offered as service subscription to the customer.

[0055] The described embodiments may be implemented using standard programming and engineering techniques related to software, firmware, hardware, or any combination thereof. The described operations may be implemented as code maintained in a non-transitory "computer readable medium", where a processor may read and execute the code from the computer readable medium. The code implementing the described operations may further be implemented in hardware logic (e.g. an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.). Still further, the code implementing the described operations may be implemented in "transmission signals" transmission signal may be decoded and stored in non transitory hardware or a computer readable medium, where transmission signals may propagate through space or through a transmission media, such as an optical fiber, copper wire, etc. An "article of manufacture" comprises non-transitory computer readable medium, hardware logic, or transmission signals in which code may be implemented. A device or server in which the code implementing the described embodiments of operations is encoded may comprise a non-transitory computer readable medium or hardware logic. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention, and that the article of manufacture may comprise suitable information bearing medium known in the art. [0056] The processing sub-system, modules and devices referred herein may use a non- transitory data storage unit or data storage device. A computer network may be used for allowing interaction between two or more electronic devices or modules, and includes any form of inter/intra enterprise environment such as the world wide web, Local Area Network (LAN), Wide Area Network (WAN), Storage Area Network (SAN) or any form of Intranet or other automation and industrial communication environment relevant to the industrial plant.

[0057] While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.