This disclosure is generally directed to field devices in a plant. More specifically, this disclosure is directed to a local HART proxy server for modular smart transmitter devices.
Industrial control and automation systems are often used to automate large and complex industrial processes. These types of systems routinely include networks that facilitate communications with a wide range of industrial field devices. The field devices can include wireless sensors, wireless actuators, and wireless controllers. The Highway Addressable Remote Transducer (HART) communications protocol is a digital industrial automation protocol. HART can communicate over legacy 4-20 mA analog instrumentation wiring, sharing the pair of wires used by an older system.
HART commands are time sensitive. For the HART commands from the HART server, the response is expected within 240 ms. If delayed, there may need to be retries or other timing issues can exist on the field devices. Monitoring and control action is not optimal in time sensitive process applications involving heterogeneous mode, multi-drop mode, or in modular transmitter designs. The heterogeneous mode can include pressure, temperature, level, flow, and the like at different update rates. Also, in different instances, a device firmware upgrade takes a long time and is not optimal.
This disclosure provides a local HART proxy server for modular smart transmitter devices.
In a first example, a method is provided for managing an access request from a server. The method includes receiving, from the server, a request for accessing a field device of a plurality of field devices in an industrial process control and automation system. The method also includes sending, to the server, a response acknowledging that the request is received. The method also includes determining whether the field device is sleeping. The method also includes, responsive to the field device being asleep, holding the request in a queue.
In a second example, an apparatus includes a memory comprising a queue. The apparatus also includes a processing device coupled to the memory. The processing device is configured to receive, from a server, a request for accessing a field device of a plurality of field devices in an industrial process control and automation system. The processing device is also configured to send, to the server, a response acknowledging that the request is received. The processing device is also configured to determine whether the field device is sleeping. The processing device is also configured to, responsive to the field device being asleep, hold the request in the queue.
In a third example, a non-transitory computer readable medium includes a computer program. The computer program comprises computer readable program code for receiving, from the server, a request for accessing a field device of a plurality of field devices in an industrial process control and automation system. The computer readable program code is also for sending, to the server, a response acknowledging that the request is received. The computer readable program code is also for determining whether the field device is sleeping. The computer readable program code is also for, responsive to the field device being asleep, holding the request in a queue.
For a more complete understanding of this disclosure and its features, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
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At least one network 104 is coupled to the sensors 102a and actuators 102b. The network 104 facilitates interaction with the sensors 102a and actuators 102b. For example, the network 104 could transport measurement data from the sensors 102a and provide control signals to the actuators 102b. The network 104 could represent any suitable network or combination of networks. As particular examples, the network 104 could represent an Ethernet network, an electrical signal network (such as a HART or FOUNDATION FIELDBUS network), a pneumatic control signal network, or any other or additional type(s) of network(s).
In the Purdue model, “Level 1” may include one or more controllers 106, which are coupled to the network 104. Among other things, each controller 106 may use the measurements from one or more sensors 102a to control the operation of one or more actuators 102b. For example, a controller 106 could receive measurement data from one or more sensors 102a and use the measurement data to generate control signals for one or more actuators 102b. Each controller 106 includes any suitable structure for interacting with one or more sensors 102a and controlling one or more actuators 102b. Each controller 106 could, for example, represent a multivariable controller, such as a Robust Multivariable Predictive Control Technology (RMPCT) controller, or other type of controller implementing model predictive control (MPC) or other advanced predictive control (APC). As a particular example, each controller 106 could represent a computing device running a real-time operating system.
Two networks 108 are coupled to the controllers 106. The networks 108 facilitate interaction with the controllers 106, such as by transporting data to and from the controllers 106. The networks 108 could represent any suitable networks or combination of networks. As particular examples, the networks 108 could represent a pair of Ethernet networks or a redundant pair of Ethernet networks, such as a FAULT TOLERANT ETHERNET (FTE) network from HONEYWELL INTERNATIONAL INC.
At least one switch/firewall 110 couples the networks 108 to two networks 112. The switch/firewall 110 may transport traffic from one network to another. The switch/firewall 110 may also block traffic on one network from reaching another network. The switch/firewall 110 includes any suitable structure for providing communication between networks, such as a HONEYWELL CONTROL FIREWALL (CF9) device. The networks 112 could represent any suitable networks, such as a pair of Ethernet networks or an FTE network.
In the Purdue model, “Level 2” may include one or more machine-level controllers 114 coupled to the networks 112. The machine-level controllers 114 perform various functions to support the operation and control of the controllers 106, sensors 102a, and actuators 102b, which could be associated with a particular piece of industrial equipment (such as a boiler or other machine). For example, the machine-level controllers 114 could log information collected or generated by the controllers 106, such as measurement data from the sensors 102a or control signals for the actuators 102b. The machine-level controllers 114 could also execute applications that control the operation of the controllers 106, thereby controlling the operation of the actuators 102b. In addition, the machine-level controllers 114 could provide secure access to the controllers 106. Each of the machine-level controllers 114 includes any suitable structure for providing access to, control of, or operations related to a machine or other individual piece of equipment. Each of the machine-level controllers 114 could, for example, represent a server computing device running any operating system. Although not shown, different machine-level controllers 114 could be used to control different pieces of equipment in a process system (where each piece of equipment is associated with one or more controllers 106, sensors 102a, and actuators 102b).
One or more operator stations 116 are coupled to the networks 112. The operator stations 116 represent computing or communication devices providing user access to the machine-level controllers 114, which could then provide user access to the controllers 106 (and possibly the sensors 102a and actuators 102b). As particular examples, the operator stations 116 could allow users to review the operational history of the sensors 102a and actuators 102b using information collected by the controllers 106 and/or the machine-level controllers 114. The operator stations 116 could also allow the users to adjust the operation of the sensors 102a, actuators 102b, controllers 106, or machine-level controllers 114. In addition, the operator stations 116 could receive and display warnings, alerts, or other messages or displays generated by the controllers 106 or the machine-level controllers 114. Each of the operator stations 116 includes any suitable structure for supporting user access and control of one or more components in the system 100. Each of the operator stations 116 could, for example, represent a computing device running any operating system.
At least one router/firewall 118 couples the networks 112 to two networks 120. The router/firewall 118 includes any suitable structure for providing communication between networks, such as a secure router or combination router/firewall. The networks 120 could represent any suitable networks, such as a pair of Ethernet networks or an FTE network.
In the Purdue model, “Level 3” may include one or more unit-level controllers 122 coupled to the networks 120. Each unit-level controller 122 is typically associated with a unit in a process system, which represents a collection of different machines operating together to implement at least part of a process. The unit-level controllers 122 perform various functions to support the operation and control of components in the lower levels. For example, the unit-level controllers 122 could log information collected or generated by the components in the lower levels, execute applications that control the components in the lower levels, and provide secure access to the components in the lower levels. Each of the unit-level controllers 122 includes any suitable structure for providing access to, control of, or operations related to one or more machines or other pieces of equipment in a process unit. Each of the unit-level controllers 122 could, for example, represent a server computing device running any operating system. Although not shown, different unit-level controllers 122 could be used to control different units in a process system (where each unit is associated with one or more machine-level controllers 114, controllers 106, sensors 102a, and actuators 102b).
Access to the unit-level controllers 122 may be provided by one or more operator stations 124. Each of the operator stations 124 includes any suitable structure for supporting user access and control of one or more components in the system 100. Each of the operator stations 124 could, for example, represent a computing device running any operating system.
At least one router/firewall 126 couples the networks 120 to two networks 128. The router/firewall 126 includes any suitable structure for providing communication between networks, such as a secure router or combination router/firewall. The networks 128 could represent any suitable networks, such as a pair of Ethernet networks or an FTE network.
In the Purdue model, “Level 4” may include one or more plant-level controllers 130 coupled to the networks 128. Each plant-level controller 130 is typically associated with one of the plants 101a-101n, which may include one or more process units that implement the same, similar, or different processes. The plant-level controllers 130 perform various functions to support the operation and control of components in the lower levels. As particular examples, the plant-level controller 130 could execute one or more manufacturing execution system (MES) applications, scheduling applications, or other or additional plant or process control applications. Each of the plant-level controllers 130 includes any suitable structure for providing access to, control of, or operations related to one or more process units in a process plant. Each of the plant-level controllers 130 could, for example, represent a server computing device running any operating system.
Access to the plant-level controllers 130 may be provided by one or more operator stations 132. Each of the operator stations 132 includes any suitable structure for supporting user access and control of one or more components in the system 100. Each of the operator stations 132 could, for example, represent a computing device running any operating system.
At least one router/firewall 134 couples the networks 128 to one or more networks 136. The router/firewall 134 includes any suitable structure for providing communication between networks, such as a secure router or combination router/firewall. The network 136 could represent any suitable network, such as an enterprise-wide Ethernet or other network or all or a portion of a larger network (such as the Internet).
In the Purdue model, “Level 5” may include one or more enterprise-level controllers 138 coupled to the network 136. Each enterprise-level controller 138 is typically able to perform planning operations for multiple plants 101a-101n and to control various aspects of the plants 101a-101n. The enterprise-level controllers 138 can also perform various functions to support the operation and control of components in the plants 101a-101n. As particular examples, the enterprise-level controller 138 could execute one or more order processing applications, enterprise resource planning (ERP) applications, advanced planning and scheduling (APS) applications, or any other or additional enterprise control applications. Each of the enterprise-level controllers 138 includes any suitable structure for providing access to, control of, or operations related to the control of one or more plants. Each of the enterprise-level controllers 138 could, for example, represent a server computing device running a any operating system. In this document, the term “enterprise” refers to an organization having one or more plants or other processing facilities to be managed. Note that if a single plant 101a is to be managed, the functionality of the enterprise-level controller 138 could be incorporated into the plant-level controller 130.
Access to the enterprise-level controllers 138 may be provided by one or more operator stations 140. Each of the operator stations 140 includes any suitable structure for supporting user access and control of one or more components in the system 100. Each of the operator stations 140 could, for example, represent a computing device running any operating system.
Various levels of the Purdue model can include other components, such as one or more databases. The database(s) associated with each level could store any suitable information associated with that level or one or more other levels of the system 100. For example, a historian 141 can be coupled to the network 136. The historian 141 could represent a component that stores various information about the system 100. The historian 141 could, for instance, store information used during production scheduling and optimization. The historian 141 represents any suitable structure for storing and facilitating retrieval of information. Although shown as a single centralized component coupled to the network 136, the historian 141 could be located elsewhere in the system 100, or multiple historians could be distributed in different locations in the system 100.
In particular embodiments, the various controllers and operator stations in
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The memory 212 and a persistent storage 214 are examples of storage devices 206, which represent any structure(s) capable of storing and facilitating retrieval of information (such as data, program code, and/or other suitable information on a temporary or permanent basis). The memory 212 may represent a random access memory or any other suitable volatile or non-volatile storage device(s). The persistent storage 214 may contain one or more components or devices supporting longer-term storage of data, such as a ready only memory, hard drive, Flash memory, or optical disc.
The communications unit 208 supports communications with other systems or devices. For example, the communications unit 208 could include a network interface that facilitates communications over at least one Ethernet, HART, FOUNDATION FIELDBUS, cellular, Wi-Fi, universal asynchronous receiver/transmitter (UART), serial peripheral interface (SPI) or other network. The communications unit 208 could also include a wireless transceiver facilitating communications over at least one wireless network. The communications unit 208 may support communications through any suitable physical or wireless communication link(s). The communications unit 208 may support communications through multiple different interfaces, or may be representative of multiple communication units with the ability to communication through multiple interfaces.
The I/O unit 210 allows for input and output of data. For example, the I/O unit 210 may provide a connection for user input through a keyboard, mouse, keypad, touchscreen, or other suitable input device. The I/O unit 210 may also send output to a display, printer, or other suitable output device.
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One or more embodiments of this disclosure provide a proxy server based field transmitter device. Using a proxy server improves HART server client response (no delays) for time-sensitive HART commands. The proxy server can also provide an improved monitoring and control system. When using a proxy server, the system can enable sleeping of other modules, such as display, sensor, and the like. As used herein, when a device is sleeping, the device may be powered off or in a standby mode. When the device is awake, the device is in a powered on mode or not in standby. Using the proxy server can also enable packet aggregation and decompression. The local proxy server also enables an optimized firmware upgrade.
The proxy server reduces request-response time, thereby enabling better and faster control action on a multi-drop loop line. The proxy server enhances device components' lifetime by enabling optimal sleep for the components. Proxy server can be used to upgrade firmware of other modules (sensor firmware, display firmware) in an optimal procedure.
The proxy server can also be used to increase the speed of the firmware upgrade process on multi-drop devices. The proxy server also reduces an overall current consumption of the field device. For example, a display module need not be active all the time, and the proxy server wakes up the display module based on user red-button operation. The additional firewall in the proxy server increases the safety of the device and bad configurations or firmware binary upgrades can be avoided at no additional cost.
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In one or more embodiments herein, a field transmitter device 306 can be a field device used in a process control system supporting protocols such as HART, Wireless HART, Foundation Fieldbus, ISA100, Profibus DP, PA, Profinet, etc. In different embodiments of this disclosure, the field transmitter device 306 can represent, or be represented by sensor 102a or actuator 102b as shown in
In an embodiment of this disclosure, the field transmitter device 306 further includes a sensor board 308, communication board 310, and remote local display 312. The sensor board 308 can control a sensor for taking measurements of different environment changes. The sensor board 308 can include memory such as, but not limited to, EEPROM 314, a microcontroller 316, and a signal conditioning module and sensor 318.
The communication board 310 can communicate with different components of the field transmitter device 306 as well as the modem 304. The communication board can include a co-processor 322 that can operate as a proxy server, a microcontroller 324, and a HART converter 326 configured to communicate over a 4-20 mA loop.
The remote local display 312 can include a microcontroller 328. The remote local display 312 can provide readouts for current and/or past measurements, configuration settings, and the like.
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One or more embodiments of this disclosure recognize and take into account that a 4-20 mA loop field transmitter is limited by availability of current. Whenever HART host 302 sends request 410, such as a read/write command, where the response requirement is a maximum up to 250 ms, if a response 412 is not received from the HART enabled field device, the request times out. To achieve this timing requirement, a field device may need to be awake at all times.
One or more of the components (like sensor 308, display 312, etc.) on the field device do not need to be active at all times other than to meet the timing requirement for request responses. Enabling sleep in these components can result in a reduction of overall current consumption. A server and firewall 404 running on a microcontroller, in the field device, can put components on the field transmitter to sleep, thus reducing overall current consumption.
Whenever a read/write command, such as request 410, is received, such as for display module 312 from HART host 302, the response 412 is generated (within the required time, such as, for example 250 ms, to meet HART host requirements) upfront by the proxy server 402. Until the display 312 comes out of sleep, the data packets are buffered in an adaptive queue 408.
In one embodiment, the queue sizes can be constant. In other embodiments, queue sizes for different components (sensor 308, display 312, etc.) are different based on their respective sleep times. The sleep times for different modules (e.g., display 312) can be user configurable. The sleep time for the sensor may be defined based on accuracy and sensing parameter requirements. The proxy server 402 can act as a sleep scheduler for different devices based on user red-button operations and/or HART host 302 activity. The proxy server 402 can wake up the display 312 based on user red-button operations. The proxy server 402 can perform dynamic prioritization of sleep/wake of different modules.
In one or more embodiments of this disclosure, proxy server 402 maintains adaptive queues for communication between different modules (between HART host 302 and sensor 308, HART host 302 and display 312, and display 312 and sensor 308) to enable optimal sleep durations for different modules.
The proxy server 402 reduces current consumption and the firewall 404 enables safety by avoiding unauthorized and out of bound configurations.
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Without a local proxy server, a response time per HART transaction could be nearly 140 ms in a temperature transmitter and nearly 60 ms in pressure sensor. The delay in response can be eliminated with a local proxy server. Firmware upgrade time can be reduced from hours to minutes.
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At operation 905, a processor is configured to receive, from a server, a request for accessing a field device of a plurality of field devices in an industrial process control and automation system. In one embodiment, the server can be a HART host. In different embodiments, the accessing can be for monitoring the field device, reading from the field device, or writing to the field device.
At operation 910, a processor is configured to send, to the server, a response acknowledging that the request is received. At operation 915, the processor is configured to determine whether the field device module (like sensor or display) is sleeping. To determine whether the field device module is sleeping, the processor can check a schedule of when the module should be sleeping and/or ping the field device module to verify a status.
If the field device module is sleeping, at operation 920, the processor is configured to hold the request in a queue. If the field device module is not sleeping, at operation 925, the processor is configured to send the request to the field device modules.
As discussed herein, one or more steps can be performed by a processor or different components controlled by the processor. However, the processor can directly perform the steps performed by components controlled by the processor.
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In some embodiments, various functions described above are implemented or supported by a computer program that is formed from computer readable program code and that is embodied in a computer readable medium. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.
It may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer code (including source code, object code, or executable code). The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.
While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.