Parallel Operation of Input / Output (IO) Modules in a Duplex Configuration

Abstract

Related to parallel operation of input / output (IO) modules in a duplex configuration. Implementations of the present disclosure may include a system that may include a first input / output (IO) module that may output a first current output. The first IO module may be coupled to a first terminal and a second terminal. The system may include a second IO module that may output a second current output. The second IO module may be coupled to the first terminal and the second terminal. The system may include a load device coupled to the first terminal and the second terminal. The load device may operate based on the first current output and the second current output. The system may include one or more control systems that receive instructions for performing a coordinated switch to the first IO module.

Description

Technical Field

[0001] The present disclosure relates generally to industrial automation systems, and more particularly to control systems and methods based on concurrent operation of redundantly connected distributed modular input / output (IO) devices (eg, IO modules) that jointly supply a load. Background Art

[0002] This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the present technology described and / or claimed below. It is believed that this discussion will help provide the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Therefore, it should be understood that these statements are to be understood in this light and not as admissions of prior art.

[0003] Industrial automation systems may include automation control and monitoring systems. The automation control and monitoring systems may monitor and / or receive status information and / or sensory data from various devices, such as valves, motors, various types of sensors, other suitable monitoring devices, and the like. In addition, one or more components of the automation control and monitoring system, such as programming terminals, automation controllers, input / output (IO) modules, communication networks, human-machine interface (HMI) terminals, and the like, may use conditions and / or collected information to provide alerts to operators to change or adjust the operation of one or more components of the industrial automation system (e.g., such as adjusting the operation of one or more actuators) to manage the industrial automation system, and the like.

[0004] The availability of an industrial automation system can be stated in terms of the availability of the services it provides to the operator or owner. It may be unacceptable to take a portion of an industrial automation system offline when maintenance occurs. It may also be unacceptable to shut down a portion of an industrial automation system when performing planned maintenance or upgrades. An example minimum availability level for petrochemical applications may be "five nines" or a service availability of 99.999% of the time. This means that the industrial automation system is down for a maximum of about 5 minutes a year. Five nines can be found in customer specifications that define target operations for industrial automation systems (such as the target high availability to be achieved by process control systems and / or safety instrumented systems). An industrial automation system may include multiple critical subsystems that may be expected to achieve higher levels of availability to meet the target availability. However, availability should be balanced with reliability. For example, an industrial automation system may be highly available (e.g., because the system is repairable) and not very reliable due to undetected operations that cause the industrial automation system to be completely or partially offline. Therefore, it may be desirable to promote industrial automation systems and methods that promote high availability and improve system reliability. Summary of the Invention

[0005] Below is an overview of some embodiments disclosed herein. It should be understood that these aspects are presented merely to provide the reader with a brief overview of these certain embodiments, and these aspects are not intended to limit the scope of this disclosure. In fact, this disclosure may encompass various aspects that may not be stated below.

[0006] In one embodiment, a system may include a first input / output (IO) module that can output a first current output. The first IO module can be coupled to a first terminal and a second terminal. The system may include a second IO module that can output a second current output. The second IO module can be coupled to the first terminal and the second terminal. The system may include a load device coupled to the first terminal and the second terminal. The load device can operate based on the first current output and the second current output. The system may include one or more control systems that receive an instruction to perform a coordinated handoff to the first IO module. In response to receiving the instruction, the one or more control systems may send a first command to the first IO module to increase the first current output and send a second command to the second IO module to reduce the second current output.

[0007] In another embodiment, the system may include a first input / output (IO) module that can receive a first current input. The first IO module can be coupled to a first terminal and a second terminal. The system may include a second IO module configured to receive a second current input, and the second IO module can be coupled to the first terminal and the second terminal. The system may include a load device coupled to the first terminal and the second terminal. The load device can output the first current input and the second current input. In addition, the system may include one or more control systems. The one or more control systems can receive an instruction for performing a coordinated switch to the second IO module; in response to receiving the instruction, send a first command to the first IO module to adjust the first resistance of the first IO module; and send a second command to the second IO module to adjust the second resistance of the second IO module.

[0008] In another embodiment, a method may include receiving, via processing circuitry, an instruction to perform coordinated switching of a digital load device to a first input / output (IO) module. The digital load device may be coupled to the first IO module and the second IO module via at least two terminals. The method may also include: in response to receiving the instruction, detecting, via the processing circuitry, a first digital state of the first IO module; and detecting, via the processing circuitry, a second digital state of the second IO module. The method may include: in response to determining that the first digital state and the second digital state are the same, sending, via the processing circuitry, a command to close at least one switch of the second IO module, thereby disconnecting the second IO module from the digital load device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like reference numerals represent like parts throughout:

[0010] Figure 1 is a diagrammatic representation of an example petrochemical-related process according to an embodiment;

[0011] Figure 2 is a diagram of an industrial automation system including a distributed control system (DCS) according to an embodiment;

[0012] Figure 3 is a diagram of a distributed modular input / output (IO) system according to an embodiment;

[0013] Figure 4 According to an embodiment, the present invention includes at least a first IO module and a second IO module. Figure 3 A block diagram of a distributed modular IO system, wherein at least one IO module includes Figure 5 General IO circuit;

[0014] Figure 5 According to the implementation method Figure 4 a circuit diagram of a general IO circuit of a first IO module;

[0015] Figure 6 is a circuit diagram of a first IO module and a second IO module coupled in parallel and redundantly to a load via analog outputs according to an embodiment;

[0016] Figure 7 is a circuit diagram of a first IO module and a second IO module coupled in parallel and redundantly to a load via analog inputs according to an embodiment;

[0017] Figure 8is a circuit diagram of a first IO module and a second IO module coupled to a load in parallel and redundantly via digital outputs according to an embodiment;

[0018] Figure 9 is a circuit diagram of a first IO module and a second IO module coupled in parallel and redundantly to a load via digital inputs according to an embodiment; and

[0019] Figure 10 is a flow chart of a process for operating a first IO module to perform a coordinated switch to a second IO module, according to an embodiment. DETAILED DESCRIPTION

[0020] One or more specific embodiments are described below. In order to provide a concise description of these embodiments, not all features of actual implementations are described in this specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may vary from implementation to implementation. Furthermore, it should be understood that such development efforts may be complex and time-consuming, but for those of ordinary skill having the benefit of this disclosure, this remains a routine task of design, manufacturing, and production.

[0021] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," and "the" are intended to indicate that there are one or more elements. The terms "comprising," "including," and "having" are intended to be open-ended and indicate that there may be additional elements other than the listed elements. Furthermore, it should be understood that reference to "one embodiment" or "an embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0022] The present disclosure is generally directed to systems and methods related to industrial automation that use redundant, parallel-operating IO modules to send or receive analog inputs, analog outputs, digital inputs, and / or digital outputs to a shared load. The use of parallel and redundant IO modules can provide industrial automation systems with enhanced capabilities to respond to component-level operational changes and electrical faults, and can result in improved reliability and higher system availability. For example, high availability can be manifested as a combination of a high mean time to failure (MTTF) and a low mean time to repair (MTTR).

[0023] To elaborate, a redundant power supply can provide power to two or more power conditioners, which can redundantly and in parallel supply power to one or more IO modules. Two or more IO modules can be paired in a duplex configuration to redundantly and in parallel interface with a shared load. For example, a secondary power conditioner can back up a primary power conditioner so that the secondary power conditioner and the primary power conditioner can supply power in parallel to two or more IO modules that are redundantly and in parallel coupled to a shared load. Since these IO modules are simultaneously interfaced with the shared load, if the primary IO module and / or the primary power conditioner are offline, the load can be switched to communicate with the secondary IO module without causing an interruption in the operation of the load. In fact, if the primary IO module, the primary power supply and / or the primary power conditioner become unavailable, the secondary power supply and the secondary power conditioner become the power source for the load and / or the secondary IO module becomes the communication interface for the load.

[0024] When coupled to the two or more IO modules, the load may lose the ability to communicate with the distributed control system when both IO modules are unavailable, but the load may still be able to communicate if the primary IO module is lost. Therefore, since there is less chance that a single failure will make both IO modules unavailable to the load, common causes of operational downtime may occur less frequently. In other words, unless there is a power outage affecting both power supplies to both IO modules, the load will still have access to power. In addition, since the secondary IO module provides power to the load in parallel with the primary IO module, the load does not have to switch to the secondary IO module to receive power even if the primary IO module becomes unavailable. Since there is no "dead time" during the engagement and disengagement between the load and the IO module, the load may experience less signal transient noise than is typically introduced during the switching process. Additional redundant systems are also described herein to further improve the reliability and availability of industrial automation, which may also reduce the likelihood of a load going offline.

[0025] This parallel and redundant operation may also make it difficult or undesirable to take an IO module offline (such as for verification testing or replacement). In fact, taking one IO module offline may interfere with the signal provided from another IO module. To remedy this, two or more IO modules can perform coordinated handoff operations. To transfer the load from being supplied by the primary and secondary IO modules, the control system can perform coordinated handoff operations to transfer the shared load to only one of the IO modules.

[0026] During a coordinated switching operation, the control system can reduce the output from or input to the primary IO module (e.g., power, current, voltage) at a rate that matches the rate at which the output from or input to the secondary IO module (e.g., power, current, voltage) is increased. This can be done incrementally or by moving individual outputs to setpoint values. After the control system has determined that the load has switched from being supplied jointly by the IO modules to being supplied solely by the secondary IO module, the load can continue its normal operation without causing disruption to any connected devices. In some cases, such as when maintenance operations are to be performed, the control system can decouple the primary IO module from the load after the load has been switched to the secondary IO module. In some embodiments, the control system can use the coordinated switching operation to perform diagnostic operations. One example diagnostic operation can involve the control system confirming that the secondary IO module can supply the full load in the event that the primary IO module becomes unavailable in the future, for periodic diagnostic testing operations. Another example diagnostic operation can involve the control system performing a full load test on the channel power supply (e.g., terminal T1) when in a duplex configuration and / or performing a full load test on terminal T2 when in duplex analog output mode.

[0027] The independent operation of different parts of the industrial automation system can enhance the diagnostic capabilities of the industrial automation system. In fact, making both IO modules active and participating in the supply load can make it possible to perform advanced module diagnostics that are transparent to the load, thereby not affecting the load operation. System-wide diagnostic operations can be performed based on the operation of different individual IO modules (e.g., loads) of the monitored industrial automation system. The IO module may also include a sensing circuit system to obtain the measurement results of the current, voltage, temperature or any metric of a part of the power conditioner or the load for diagnostic operations. These measurement results can enhance field control determination. For example, the local control system of a device can adjust its operation based on the measurement performed in another device without the intervention of the system-wide control system. The health monitoring provided by the diagnostic capability can make it possible to detect that the backplane, power conditioner and / or power supply cannot support the full load when one of the power supplies is unavailable. Health monitoring at the IO module level (e.g., load module level) can also make it possible to detect a load module that cannot support its own load when one of the power rails fails.

[0028] Using consistent or similar (e.g., universal) IO circuitry within IO modules can further improve industrial automation system operation. Because IO modules with specific IO circuitry can be modular and identical relative to each other, using these IO modules can help conserve resources when maintaining a large number of IO modules to maintain operation of the industrial automation system and can reduce the likelihood of operator error when repairing and / or installing IO modules.

[0029] Note that sometimes those IO modules operating in parallel operation provide equal amounts of power to the load. However, it may be desirable for these IO modules to generate or receive unequal amounts of power and / or outputs (such as voltage outputs). In practice, the secondary IO module can have an output voltage (e.g., the output voltage from terminal T1) that is lower than the output voltage setting of the primary IO module so that the primary IO module sources power to the load under normal operating conditions. If the primary IO module becomes unavailable, switching the load from being sourced by the primary IO module to being sourced by the secondary IO module does not introduce switching transients because the secondary IO module remains coupled to the load during normal operation and throughout the regulation of the output voltage from the secondary IO module.

[0030] Although the following example environment in which the present embodiments may be implemented is described with respect to petrochemical applications, it should be understood that parallel and redundant power supply and distribution systems may also improve operations in other applications. For example, burner management applications, gas production applications, mining applications, and / or other heavy industrial applications, as well as any system where improved reliability and efficiency (e.g., less downtime) are desired, may benefit from the embodiments described herein.

[0031] By way of introduction, Figure 1 is a diagrammatic representation of a petrochemical related process in which the embodiments described below may be implemented. Specifically, an example reactor system 10 is shown, such as a polymerization reactor capable of processing olefin monomers (e.g., ethylene or hexene) to produce homopolymers or copolymers as products 12. Any suitable reactor may be used, including batch reactors, slurry reactors, gas phase reactors, solution reactors, high pressure reactors, tubular reactors, or autoclave reactors, or any combination thereof. For ease of discussion, Figure 1 It is referred to as a loop reactor 14 for polymerization. However, it should be noted that the discussion set forth below is intended to be appropriately applicable to any petrochemical process, industrial process, manufacturing process, etc., as a reference to Figures 2 to 9 The following discussion provides context.

[0032] Production process, such as Figure 1The polymerization reactor process shown in FIG can occur on an ongoing basis as part of a continuous operation to produce a product (e.g., product 12). Sometimes, various continuous and batch systems can be used throughout the production process. Various suppliers can provide reactor feed 16 to reactor system 10 via pipelines, trucks, drums, vats, etc. Suppliers can include off-site facilities and / or on-site facilities, including olefin plants, refineries, catalyst plants, on-site laboratories or off-site laboratories, etc. Examples of possible feed 16 include olefin monomer 18, diluent or diluent 20, catalyst 22, and / or other additives. Other feed components—additional raw materials 24—can also be provided to reactor 14. Feed 16 can vary when using different manufacturing processes and / or when producing different end products. Feed 16 can be stored or handled in any suitable container or process before or after being received at reactor system 10, such as in monomer storage and feed tanks, diluent containers, catalyst tanks, co-catalyst drums and tanks, processing beds such as molecular sieve beds and / or aluminum packing, etc. The reactor system 10 may include one type of reactor or multiple reactors of the same or different types in the system, and the desired processing conditions in one of the reactors may differ from the operating conditions of the other reactors.

[0033] The product 12 may be removed from the reactor system 10 for additional processing, such as forming polymer pellets from the product 12. Typically, the product 12 or processed product (e.g., pellets) may be transported to a product loading area for storage, mixing with other products or processed products, and / or loading into railcars, trucks, bags, ships, etc. for distribution to customers.

[0034] A process, such as the reactor system 10, may receive or process the feed 16 at a relatively high pressure and / or relatively high temperature. For example, a hydrogen feed may be processed by the reactor system 10 via a pipeline at approximately 900 to 1000 pounds per square inch gauge (psig) at 90°F to 110°F. In addition, highly reactive, unstable, corrosive, or other toxic materials may be used as feed 16 or as intermediates (such as hydrogen sulfide, pure oxygen, etc.) to generate some products. Heat, pressure, and other operating parameters may be appropriately employed to obtain appropriate reaction conditions, which may increase the reactivity, instability, or corrosiveness of the feed 16. It may be desirable to use reliable and highly available systems to handle and transport these materials, for example, to reduce the likelihood of a release event.

[0035] Each of the feed 16, sub-reactor 26 and / or feed system 32 can use different operating parameters to produce a suitable output intermediate product for subsequent reaction or output as a product. The operating parameters of the reactor system 10 may include temperature, pressure, flow rate, mechanical stirring, product output, component concentration, polymer productivity, etc., and one or more may be selected to achieve the desired polymer properties. Controlling the temperature may include using a gas burner, an electric heating conduit, a heat exchange device 28, etc. to increase or decrease the temperature of the intermediate product of the reactor system 10. As an example, during operation, a cooling fluid may be circulated in the cooling jacket of the heat exchange device 68 as needed to remove the generated heat and maintain the temperature within the desired range, for example, between about 150°F and 250°F (65°C to 121°C) for polyethylene.

[0036] This can be done by controlling the system (e.g. Figure 2 A control system (shown) manages the flow rate of feedstock 16, control of operating parameters, and the like. The control system can generate control signals, such as control signals transmitted to one or more actuators 30 to cause the actuators to open or close (or partially open or partially close), as a means of controlling operating parameters of feedstock 16, controlling other operating parameters, and the like. Care should be taken when adjusting operating parameters, as petrochemical production processes can be very sensitive to operational errors. For example, the percentage of reliability change in the control system of reactor system 10 can make the difference between a process that is offline and a process that is operating as expected.

[0037] With the foregoing in mind, the components of the reactor system 10 can be connected to power supplies, power conditions, and other systems that make the components highly available. Additionally, it should be noted that the embodiments described herein can be implemented in a variety of industrial environments and should not be limited to the reactor system 10 described above.

[0038] Now refer to Figure 2 , Figure 2 is a diagram of an example industrial automation system 46 that includes a distributed control system 48 (e.g., a "DCS"). The industrial automation system 46 may include Figure 1 The reactor system 10 and / or any number of industrial automation components.

[0039] Industrial automation components can include user interfaces, distributed control systems 48, motor drives, motors, conveyors, specialized original equipment manufacturer machines, fire extinguishing systems, and any other devices that can produce or manufacture products or process certain materials. In addition to the types of industrial automation components mentioned above, industrial automation components can also include controllers, input / output (IO) modules, motor control centers, motors, human-machine interfaces (HMIs), user interfaces, contactors, starters, sensors, drives, relays, protection devices, switching devices, compressors, network switches (e.g., Ethernet switches, modular managed switches, fixed managed switches, service router switches, industrial switches, unmanaged switches), etc. Industrial automation components can also be associated with various industrial equipment (such as mixers, machine conveyors, tanks, pallets, specialized original equipment manufacturer machines, etc.). Industrial automation components can also be associated with devices used in conjunction with equipment (such as scanners, measuring instruments, valves, etc.). In one embodiment, each aspect of the industrial automation component can be controlled or operated by a single controller (e.g., a control system). In another embodiment, the control and operation of each aspect of the industrial automation component can be distributed via multiple controllers (e.g., control systems).

[0040] The industrial automation system 46 may be logically and physically divided into different units 50 corresponding to units, areas, plants, subsystems, etc. of the industrial automation system 46. Industrial automation components (e.g., load components, processing components) may be used within the units 50 to perform various operations for the units 50. Industrial automation components may also be logically and / or physically divided into the units 50 to control the performance of various operations for the units 50.

[0041] The distributed control system 48 may include a computing device having communication capabilities, processing capabilities, etc. For example, the distributed control system 48 may include a processing module, a control system, a programmable logic controller (PLC), a programmable automation controller (PAC), or any other controller that can monitor, control, and operate an industrial automation device or component. The distributed control system 48 may be incorporated into any physical device (e.g., an industrial automation component) or may be implemented as a standalone computing device (e.g., a general-purpose computer), such as a desktop computer, a laptop computer, a tablet computer, a mobile computing device, etc. For example, the distributed control system 48 may include a number of processing devices logically arranged in a hierarchy to implement control operations by propagating control signals, monitoring the operation of the industrial automation system 46, recording data as part of historical tracking operations, etc.

[0042] In the example distributed control system 48, devices at different hierarchical levels may correspond to different operations. The first level 52 may include input / output communication modules (IO modules) to interface with industrial automation components in the unit 50. The second level 54 may include a control system that controls components of the first level and / or enables intercommunication between components of the first level 52, even when the components of the first level 52 are not communicatively coupled within the first level 52. The third level 56 may include network components, such as network switches, that support the availability of electronic communication modes between industrial automation components. The fourth level 58 may include server components, such as application servers, data servers, human-machine interface servers, etc. The server components may store data as part of these servers, enabling industrial automation operations to be monitored and adjusted over time. The fifth level 60 may include computing devices, such as virtual computing devices operated from servers, to enable human-machine interaction through an HMI presented via the computing devices. It should be understood that the levels of the hierarchy are not exhaustive and non-exclusive, and thus, devices described in any level may be included in any other level. For example, any level may include some variation of an HMI.

[0043] One or more of the levels or components of the distributed control system 48 may use and / or include one or more processing components, including microprocessors (e.g., field programmable gate arrays, digital signal processors, application specific instruction set processors, programmable logic devices, programmable logic controllers), tangible, non-transitory machine-readable media (e.g., memory such as non-volatile memory, random access memory (RAM), read-only memory (ROM)), etc. The machine-readable media may collectively store one or more instruction sets (e.g., algorithms) in the form of computer-readable code and may be grouped into applications according to the type of control performed by the distributed control system 48. In this manner, the distributed control system 48 may be application-specific or general purpose.

[0044] Furthermore, a portion of the distributed control system 48 may be a closed-loop control system (e.g., without feedback for control), an open-loop control system (e.g., with feedback for control), or may be a portion of a closed-loop control system, an open-loop control system, or may include a combination of open-loop and closed-loop system components and / or algorithms. Furthermore, in some embodiments, the distributed control system 48 may utilize feedforward inputs. For example, depending on information related to the feedstock 16 (e.g., composition information related to the catalyst 22 and / or additional raw materials 24), the distributed control system 48 may control the flow of any one or combination of the feedstocks 16 to the sub-reactors 26, the reactor 14, etc.

[0045] Each of the levels 52, 54, 56, 58, 60 may include component redundancy, which may help provide a high availability control system. For example, within the first level, redundantly and in parallel operating backplanes may provide power to each of the IO modules.

[0046] To elaborate, Figure 3 is with Figure 2 FIG2 is a diagram of an example distributed modular IO system 72 associated with a distributed control system 48. The distributed modular IO system 72 may include IO devices 74, IO modules 76, and a backplane 78 (78A, 78B). The distributed modular IO system 72 may include a network adapter 80 having two or more adapter modules 86 (86A, 86B).

[0047] The network adapter 80 can be coupled to at least one industrial automation network N1, N2. The first redundant industrial automation network N1 and the second redundant industrial automation network N2 can be a Parallel Redundancy Protocol (PRP) LAN network, an Ethernet / IP network, or other industrial automation network, so that the network adapter 80 can receive data from, send data to, or otherwise communicate with one or more industrial control modules, control systems, processing circuit systems, etc., such as one or more programmable logic controllers (PLCs), microprocessors, and / or other electronic processors for machine and / or process control.

[0048] The network adapter 80 may include a base 82 mounted to a support rail 84 or other support structure. The network adapter 80 may include first and second identical or additional redundant adapter modules 86 (86A, 86B) that operate in parallel with each other. The redundant adapter modules 86 may each be releasably connected to an adapter base 88. Each of the adapter modules 86 may be operably connected to both the first network N1 and the second network N2 via connections in the adapter base 88. The adapter modules 86 may also include electronic circuitry to communicate data with circuitry coupled to the networks N1, N2, with the IO devices 74, or with other interconnect components.

[0049] The network adapter 80 may include first and second media landing modules 90 (90A, 90B) removably coupled to the first and second adapter modules 86 via the adapter base 88. The media landing boards 90 may each include at least two network connectors NC, such as RJ45 connectors, small form-factor pluggable (SFP) connectors, fiber optic connectors, etc. The industrial networks N1, N2 may be coupled to the media landing boards 90 via the network connectors NC and, thus, connected to the adapter module 86 through the media landing boards 90.

[0050] The IO device 74 redundantly regulates and supplies power to an IO module (power conditioner) 92 (92A, 92B), which can be coupled to the adapter base 88 and can include a power input terminal PT. The power input terminal PT can be used when connected to at least one power source so that the power conditioner 92 can supply system power to the network adapter 80 and other components coupled to the backplane 78 via the adapter base 88. As shown herein, the power input terminal PT is removably connected to the adapter base 88 and is operatively connected to the power conditioner 92 through the adapter base 88.

[0051] The IO device 74 may include a base 94 that is also mounted to the support rail 84 or another support structure. The base 94 may be located adjacent to the base 82. The base 94 may be operatively, physically, and / or electrically connected to the base 82 via a multi-contact electrical connector 96 so that the backplane 78 can provide power and communication between the network adapter 80, the IO device 74, the industrial network N, and the like. Figure 3 The backplane 78 is shown external to the IO device 74, but one of ordinary skill in the art will recognize that the backplane 78 circuitry or network is physically and electrically constructed within and extends through other circuitry and printed circuit boards located in the adapter base 88 and base 94 via the electrical connector 96.

[0052] The IO device 74 may include IO processing modules (IO modules) 98 (98A, 98B, 98C, 98D). The IO modules 98 may be removably connected to the base 94 in corresponding mounting slots via electrical connections, such that each of the IO modules 98 may be operably coupled to the backplane 78. The IO modules 98 may communicate with the network adapter 80, other IO (sub) modules 98, 100, and the like using the backplane 78. In one embodiment, at least two of the IO modules 98 are identical to each other and operate in parallel with each other to provide redundancy relative to each other.

[0053] The base 94 may include at least one terminal block 102 that may include cage clamps, spring clamps, screw terminals, or other wiring connectors 104 suitable for connecting to field cables or field wiring 110 each associated with a field device 106. The field devices 106 may be analog or digital devices, such as sensors, flow meters, switches, probes, thermocouples, RTDs, encoders, etc., and the field devices 106 may receive input data or transmit output data via the terminal block 102.

[0054] The network adapter 80 may include a standalone "adapter" Ethernet switch 112 (112A, 112B) that is operatively connected to, forms part of, and establishes the backplane 78. Similarly, the IO device 74 may include a standalone IO module Ethernet switch 114 (114A, 114B) that is operatively connected to, forms part of, and establishes the backplane 78. The switches 112 and 114 may be identical but are numbered differently to facilitate description of their operation. The switches 112, 114 may perform packet switching operations to direct data communications for any suitable backplane network / protocol.

[0055] The IO module 76 can be a single-channel IO device that includes one or more removable and replaceable single-channel IO submodules 100. The IO module 76 can include a base 118 suitable for mounting on the support rail 84 or another support structure. The base 118 can include a multi-contact electrical connector 96 to form a portion of the backplane 78. The IO module 76 can include a terminal block 120 connected to the base 116. The terminal block 120 can include wiring connectors 122 that couple the terminal block 120 to other industrial automation components. The IO module 76 can include an Ethernet switch 124 (124A, 124B), each of which is operably coupled to the backplane 78, forms a portion of the backplane 78, and establishes the backplane 78.

[0056] The IO modules 76 may include at least two configurable IO modules 126 (126A, 126B). The configurable IO modules 126 may each be defined by and include separate IO segments or IO sub-modules 100, each of which may be selectively mounted on and removed from the base 116. The configurable IO modules 126 may define a group of IO sub-modules 100. In this example, the configurable IO modules 126 each include eight single-channel IO sub-modules 100 and, therefore, eight separate IO data channels.

[0057] The IO submodules 100 and / or IO modules 108 may include electronic circuitry to perform specific types of data input / output (IO) operations, such as direct current (DC) input, DC output, alternating current (AC) input, AC output, safety input / output, Highway Addressable Remote Transducer (HART) input / output, real-time data (RTD) and / or thermocouple input and / or output, or other analog or digital input / output for data and signals. Each IO submodule 100 and / or IO module 108 may be configured for different types of data communications. Furthermore, each IO submodule 100 and / or IO module 108 may be associated with a single dedicated IO data channel that is operably coupled to a group (e.g., a column) of one or more wiring connectors 122 of a terminal block 120. In this manner, a field device coupled to one or more wiring connectors 122 may be associated with a specific IO data channel and may be operably connected to a corresponding IO submodule 100 associated with the same IO data channel. As mentioned above, the IO submodule 100 and / or IO module 108 are selected as the appropriate IO type (e.g., analog, digital, AC input, AC output, DC input, DC output) as required by the specific field devices connected to their associated IO data channels.

[0058] As described above, industrial automation system 46 may transport and process materials that may be classified as hazardous by chemical regulatory agencies and that may be used to produce products with a cumulative value of millions of dollars. Therefore, it may be desirable for industrial automation system 46 to be not only highly reliable but also highly available, for example, to meet minimum availability levels for petrochemical applications, which may be 99.999% service availability. To this end, short-term and long-term monitoring operations of industrial automation system 46 can be used to perform predictive maintenance operations, as well as reactive or other maintenance activities. For example, by monitoring the operation of individual components of industrial automation system 46, either individually or in conjunction with system-wide or unit-wide monitoring operations, maintenance issues can be predicted before components, units, and / or systems are taken offline. Predictive monitoring can improve availability by, for example, being able to schedule power outages of components, units, and / or systems when monitoring operations have flagged repair or replacement of a portion of industrial automation system 46. Short-term and long-term monitoring operations of industrial automation system 46 can be managed by components of distributed control system 48, for example, by propagating commands (and resulting data) to perform specific operations throughout various levels of distributed control system 48. Figure 4 The example component group in can be represented by Figure 3Part of a distributed modular IO system 72 that is associated with the distributed control system 48 but is used to control loads at a more local level (such as in or near the unit 50).

[0059] To elaborate, Figure 4 yes Figure 3 7. The power conditioners 92 may be coupled to power supplies 138 (138A, 138B), respectively, and may include power conversion circuitry to transform the electrical properties of signals received from the power supplies 138 before outputting the electrical signals to the backplane 78. Sometimes the field devices 106 may include IO modules 140 (140A, 140B, 140C) and sensing devices 142 (142A, 142B, 142C) associated with downstream loads. The IO modules 140 may additionally or alternatively be coupled to the backplane 78 via the backplane 78. Figure 3 IO sub-module 100 and / or IO module 108.

[0060] Additional communication paths may be included between the IO modules 140 and the power conditioner 92. The IO modules 140 may each receive analog or digital signals from the backplane 78A, the backplane 78B, or both. Signals sent via the backplane 78 may alter the operation of the individual IO modules 140. For example, the IO module 140 may serve as a system interface for downstream IO modules coupled to the IO module 140 and, therefore, may supply power from the power conditioner 92 to the system side of downstream components coupled to the IO module 140. The IO circuitry 146 of the power conditioner 92 may be used to provide feedback, such as via a DC signal transmitted between the IO module 98 (control) and the power conditioners 92A, 92B. This feedback may relate to the status of the IO module 140 and / or components coupled to the IO module 140, such as whether one or both connections to the backplane 78 are lost, or other suitable status or data related to control operations. The IO module 98 (control) or the IO module 98 (system) may be programmed and operated as a distributed modular IO system 72 control system and / or may include other control circuitry. For ease of description, the IO module 98 (control) is described herein as the primary control system for at least that portion of the distributed modular IO system 72. In some cases, the IO module 98 (system) may coordinate received signals and / or operation of the IO module 98 (control) with larger system operations by communicating with other portions of the distributed modular IO system 72.

[0061] The sensing device 142 can sense environmental conditions 150 and / or operating parameters of the IO module 140 (e.g., speed, current, output voltage), which may affect the operation of the industrial automation system 46. The sensing device 142 can acquire sensed data and can output the sensed data to other control circuit systems via input / output (IO) circuit system 146, such as Figure 3 The sensed data may be in any suitable format and thus may include one or more analog electrical signals, digital data signals, pulse width modulated data signals, or the like.

[0062] After the IO module 98 (system) receives the sensed data from the sensing device 142, the IO module 98 (system) may transmit the sensed data to the IO module 98 (control). The IO module 98 (control) may analyze the sensed data to determine one or more outputs to send to the IO module 140. In some cases, this includes providing commands to one or more power conditioners 92 to change how current is output from the power conditioners 92 coupled to the IO module 140 as a redundant pair. The power conditioners 92 may provide current to the IO module 140 in parallel. Thus, to test the output current from one of the power conditioners 92, one of the power conditioners 92 may provide power to the IO module 140 while the other power conditioner 92 does not provide power. As a result, the IO module 140 may be connected to the power conditioners 92 and avoid an increased risk of failure if one of the connected power conditioners 92 fails to provide adequate power.

[0063] The communication path with one or more IO modules 140 can also enable upstream control circuitry to diagnose or monitor the IO modules 140. In the event that one of the backplanes 78 goes offline, the control circuitry of the power conditioner 92 and / or the control circuitry of the IO modules 140 can continue to receive power from the other of the backplanes 78, thereby avoiding operational interruption due to loss of power and the need to connect the other backplane 78 to the component. Components including the control circuitry of the power conditioner 92 and / or the control circuitry of the IO modules 140 can be coupled to two or more backplanes 78.

[0064] Each of the IO modules 140 can dynamically provide different resistances in each of its channels, such as can be used to provide different operating modes for the channel. In different operating modes, the IO module 140 can send and / or receive digital signals, analog signals, or both types of signals. When the IO module 140 includes one channel, the single channel can operate in any of the different operating modes (e.g., analog input, analog output, digital input, digital output), but at different times.

[0065] When in these different operating modes, IO module 140 can support different IO signal types. IO module 140 can also support Highway Addressable Remote Transducer (HART) communication; digital industrial automation protocols that can communicate over traditional 4 milliamp to 20 milliamp (mA) analog instrument wiring; the Association of Process Automation Technology Users (NAMUR); and others. In practice, the general-purpose IO circuitry of IO module 140 (which may include channels with configurable resistance) can provide resistance established in input or output channels for proper operation in each of these IO types. The general-purpose IO circuitry can dynamically change channel resistance by adjusting channel voltage and channel current to maintain a desired channel resistance. These adjustments can be based in part on the current and / or voltage contribution of the load from IO module 140, such that the net current and voltage set the desired channel resistance. In some examples, the general-purpose IO circuitry can adjust resistance by changing resistor values, configuring digital potentiometers, adjusting a resistance ladder, and the like. In practice, each of these resistance adjustment methods can benefit from being able to provide a variety of resistances without requiring the use of separate physical resistor components for each resistor provided.

[0066] With this in mind, the present embodiment described below includes output control operations for IO modules 140 commonly coupled to a shared downstream load, which can help maintain balanced outputs from redundant IO modules 140, trigger intentional unbalance to diagnose whether both IO modules 140 can independently supply downstream loads if one IO module 140 goes offline, and detect when one of the IO modules 140 goes offline. One or more of the IO modules 140 may include general-purpose IO circuitry to process analog output signals, analog input signals, digital output signals, digital input signals, etc. Figure 5 Provides examples of analog IO circuits that can be included in general-purpose IO circuits, while Figure 6 and Figure 7 It shows how this circuit can be used to pair two or more IO modules 140 to share the load. Figures 8 and 9 shows the same circuit, but for digital input and output circuits, and Figure 10 An example method is provided for operating one of the IO modules 140 to control the output from that IO module to perform a coordinated switchover of a load to another IO module 140. For ease of discussion, IO module 140A is referred to herein as the primary IO module 140A, while IO module 140B is referred to herein as the secondary IO module 140B. However, it should be understood that any IO module 140 can operate as either a primary or secondary IO module as long as they are coupled to a shared load as a pair. It should also be understood that operations performed by the primary IO module 140A and / or the secondary IO module 140B can be similarly performed by another of the IO modules 140.

[0067] Now let's move on to the general IO circuit. Figure 5 is an example circuit diagram of a circuit portion 160 of an IO module 140A for interfacing with a load 162. The earlier system described a single universal IO module 140. Commonly assigned U.S. Patent No. 10,684,644 generally describes universal IO modules, which is incorporated herein by reference in its entirety. However, it may be desirable to couple two or more universal IO modules 140 together in a duplex configuration. By doing so, as described above, diagnostic operations can improve the availability of the entire system. In addition, while Figure 5 140B. In the circuit section 160, the primary IO module 140A can share a plurality of terminals 166 (e.g., T1, T2, T3) with the secondary IO module 140B. Each terminal 166 can receive a corresponding electrical conductor (e.g., conductors 164A, 164B, 164C) in a channel that interfaces with a load 162 (e.g., an industrial automation device, a sensor, another IO module 140, etc.). Figures 6 to 9 As shown, load 162 can be shared with one or more IO modules including secondary IO module 140B. Conductor 164 is shown as a dashed line to indicate various possibilities for connecting to load 162 according to various devices and / or modes. Thus, conductor 164 can be a wire (or other suitable conductor, such as a trace, contact, etc.) electrically coupled to load 162, which can include a sensor, actuator, etc. Load 162 can be an analog, digital, or HART device, as desired at various points in the industrial automation system 46 and / or process.

[0068] Conductors 164 may be releasably connected to primary IO module 140A and secondary IO module 140B at terminals 166, as shown. Figures 6 to 9 Terminals 166 may be screw terminals where a screwdriver may be used to releasably connect conductors 164 to primary and secondary IO modules 140A, 140B, or any suitable type of terminal.

[0069] Referring now to devices that are not shared between IO modules 140, a variable resistance device, such as switch device 168A, can be coupled to terminals 166 (e.g., T2 and T3) and provide a resistance (labeled "B") for a path in line with conductor 164B. The variable resistance device can be a transistor, such as a field effect transistor (FET), and in other embodiments can include a resistor or other impedance component.

[0070] Control system 170A may include a processor and a memory device. The memory device may be a tangible, non-transistor computer-readable medium that stores instructions for execution by the processor to perform operations. Control system 170A may control the transmission of a signal from voltage source 186A to conductor 164A via switch 188. This may control the channel resistance "A" disposed in line with conductor 164A.

[0071] A voltage source 186A, adjustable via the control system 170A, can enable duplex operation of the IO module 140. The control system 170A can set the voltage output from the voltage source 186A to be higher than the output of the corresponding voltage source 186B from the secondary IO module 140B, which can provide a "safety net" or operational buffer in the event that the primary IO module 140A goes offline. When the primary IO module 140A goes offline, the connected sensors or loads 162 do not lose power because the secondary IO module 140B takes over from a non-zero output state, resulting in fewer transients than switching in from a zero output state. The ability to adjust the voltage of the voltage source 186 also enables support for different types of field devices and IO communication standards and protocols.

[0072] Furthermore, when the load 162 supports HART communication, the control system 170A can optionally utilize a HART communication modem 190A. The HART communication modem 190A can be bidirectional, receiving and transmitting signals via capacitors c1 and c2. The HART communication modem 190A can be coupled to the voltage feedback line 174 (V_IN) via two or more lines (e.g., HART TX, HART RX), each line having capacitors c1 and c2 connected in series with the HART communication modem 190A. When receiving communications in a HART format, the HART communication modem 190A can convert the received signal into a format that can be processed by the control system 170A.

[0073] Additionally, control system 170A may be coupled to the variable resistance device, switch device 168A, and amplifier 172A. Control system 170A may control the variable resistance device to adjust resistance "B" in the path in line with conductor 164B for a given operating mode and / or load type.

[0074] The operating mode may be selected from a variety of operating modes. The operating mode may be determined by the control system 170A based on user input received at a screen of a remote device communicatively coupled to the control system 170A, a computing device of one of the levels 52 to 60 of the distributed control system 48, directly at the control system 170A and / or the master IO module 140A, or the like. The user input may indicate specifications for the load 162, which the control system 170A may use to derive various set points, including resistance "B," or may indicate the set points directly, or the like. Such user input may indicate the power, voltage, current, and / or signal frequency requirements of the load 162, whether the load 162 is a predetermined device type, such as a digital sensor, including an International Electrotechnical Commission (IEC) Type 1, 2, 3, or NAMUR sensor, a digital actuator, an analog sensor, an analog sensor operating as a HART device, or an analog actuator, or a user-defined device type. Determined operating modes can then be set, such as digital output, digital input for IEC Type 1, 2, 3 or NAMUR, analog output, analog input without HART communication, analog input with HART communication (which can be implemented in a 4mA to 20mA current loop), user-defined operating modes, etc.

[0075] Each operating mode can use a different resistance in the channel for the type of load 162. In some cases, the variable resistance device can include a transistor or switch device 168 that changes resistance when a signal received at a gate terminal selectively biases the transistor to achieve a resistance in the channel appropriate for the selected mode. The variable resistance device can include any suitable device capable of changing resistance, such as a resistance ladder. Control system 170A can adjust the value of one or more variable resistance devices in response to the type of load 162 and / or in response to additional information associated with load 162 and / or IO module 140, and the values of the variable resistance devices can thus be programmed to the same or different values. The type of load can indicate whether load 162 is a motor, a sensor, a control device, etc. and / or what type of input or output is being sent or received at terminal 166. Additional information can include metering data collected about IO module 140 and / or load 162, ambient temperature, individual path impedances that can change over time, and the like. For example, an analog load 162 at a first temperature may use a different channel resistance than the same analog load 162 at a higher temperature, a different channel resistance than a digital load 162 at the same first temperature, and so on.

[0076] Control system 170A can control switching device 168 to provide resistance in the channel corresponding to conductor 164B. To this end, control system 170A can receive feedback from the channel for amplifier 172A, which in turn can provide adjustments for switching device 168A. Feedback can be transmitted to control system 170A on voltage feedback line 174A (V_IN) and / or current feedback line 176A (I_IN). Sometimes, voltage feedback line 174A (V_IN) forms a node between switching device 168 and screw terminal 164T2, and current feedback line 176A (I_IN) forms a node between switching device 168A and current sense resistor 178A. Current sense resistor 178A can be a nominal resistor connected to system ground (e.g., system ground voltage, ground), such as 10 ohms (Ω), 15Ω, 20Ω, etc. Control system 170A can calculate the resistance of the channel based on Ohm's law (e.g., resistance equals voltage divided by current). Thus, the control system 170A can divide the voltage from the voltage feedback line 174A by the current from the current feedback line 176A to find the resistance of the variable resistance device. Based on the desired mode, the control system 170A can then adjust the resistance in the channel by adjusting the digital-to-analog converter (DAC) output 180A (ADJ) to the input of the amplifier 172A, such as the non-inverting input ("+"), so that the amplifier 172A provides the adjustment to the variable resistance device through the bias line 182A. The current feedback line 176A can also be provided to another input of the amplifier 172A that provides a reference signal (e.g., the inverting input "-"). The amplifier 172A can be any suitable type of amplifier and can receive a positive reference signal and a ground reference signal from a power supply 184A and a terminal to the system ground.

[0077] Each of the IO modules 140 may include Figure 5 , and as will be appreciated, the description above should similarly apply to IO modules having general purpose IO circuits. The secondary IO module 140B can supply loads in parallel and redundantly with the primary IO module 140A. In the event that the primary IO module 140A goes offline, the secondary IO module 140B can be stepped up to supply signals to the load 162 without interrupting the process involving the load 162 and without introducing additional switching transients into the signals. Figure 6 This connection is shown where the shared load simulates the output load.

[0078] Figure 6 yes Figure 5FIG2 is a circuit diagram of a primary IO module 140A and a secondary IO module 140B, which are coupled in parallel and redundantly to a load 162 to provide analog outputs to the load 162. The primary IO module 140A and the secondary IO module 140B can share a common terminal 166. Switches 200A1 through 200D2 can be connected between an internal connection of the IO module 140 and the common terminal 166 and, when closed, electrically disconnect the IO module 140 from the common terminal 166. Terminal T3 can ground the IO module 140 to system ground. Terminal T4 can be reserved for additional couplings, such as to allow for relay modules, resistance-based temperature detectors (e.g., resistance temperature detectors (RTDs)), thermocouples, differential voltage inputs, increased channel counts, and the like. Although the load 162 is shown between terminals T1 and T2, it should be understood that the load 162 can be coupled to any suitable combination of terminals, including each of terminals T1, T2, T3, and T4. One example simulated load 162 includes an actuator between terminals T1 and T2 as the load 162 .

[0079] The actuator emulating load 162 can be a 4mA to 20mA device that adjusts the position of a component, such as a valve, positioner, or meter, proportionally to a signal value between 4mA and 20mA, where 4mA can be the "0%" position and 20mA can be the "100%" position, although any range of current can be used to set the actuator's position. In any case, the IO modules 140 can work together to control the total current provided to load 162 via current sources 167A and 167B, voltage sources 186A and 186B, or both. Because voltage sources 186 can be individually adjusted to different or the same output value, one or more of the control systems 170 direct current from the primary IO module 140A to the secondary IO module 140B, or vice versa. This manipulation enables field devices to avoid losing power in a single fault condition (e.g., when one of the IO modules 140 goes offline).

[0080] In practice, both IO modules 140A and 140B can actively contribute current to the load in parallel, at least at times. The IO modules 140 can share the load 50% / 50%, or according to another ratio, such as 60% / 40%, 70% / 30%, etc. For example, the primary IO module 140A can contribute 5 mA to the load 162 based on the output from the current source 167A. In doing so, the secondary IO module 140B can contribute 5 mA to the load 162 based on the output from the voltage source 186B and the output from the current source 167B (which can include a variable resistance device, for example). The output from the voltage source 186B and the output from the current source 167B can be set to different values than the voltage source 186A and the current source 167A, so that the primary IO module 140A can provide voltage to the load 162, but each IO module 140 can provide current equally.

[0081] In effect, while the primary IO module 140A provides current to the analog output loop including the load 162, the secondary IO module 140B also contributes current to the analog output loop. In this manner, both IO modules 140 are simultaneously coupled to the common terminal 166. The IO modules 140 can each provide 5 milliamps (mA) of the total 10 mA to the load 162, but any current amount can be used based on the specifications of the IO modules 140 and the load 162. Because the IO modules 140 are coupled in parallel to the load 162, if the primary IO module 140A is taken offline during operation, the secondary IO module 140B can increase the output of the current source 167B to contribute the full 10 mA to the load 162. This transition from providing 5 mA to 10 mA by secondary IO module 140B produces fewer switching transients and disruptions to load 162 than a similar transition from 10 mA to 0 mA when primary module 140A becomes unavailable and a similar transition from 0 mA to 10 mA after secondary IO module 140B is connected to load 162.

[0082] The respective control system 170A or 170B can control the respective switch 188A or 188B to selectively provide power from the respective voltage source 186A or 186B to terminal T1 in the output channel used by the analog device. In operation, conductor 164A can be connected to terminal T1 and can provide power to load 162, while conductor 164B can be connected to terminal T2 and provide a return path from load 162 in a return channel that is in line with current sources 167A and 167B. Based on the load sharing instructions implemented by the control system 170, each respective control system 170A and 170B can coordinate control of current sources 167A and 167B to change the current in the channel according to the specified load sharing instructions to maintain the desired current in the channel.

[0083] With the foregoing in mind, the control system 170 can receive an indication (e.g., a fault, an alarm, a request) that one of the IO modules 140 may be de-energized or removed from the circuit. In this way, the control system 170 can perform a coordinated switching operation to ensure that the load 162 maintains its operation. By way of example, during the coordinated switching operation, the control system 170A can cause its current source 167A to decrease its output current at the same rate that the control system 170B can cause its current source 167B to increase its output current, such that the load 162 experiences a smaller change in total current. The first rate used by the current source 167A can be inversely proportional to the second rate used by the current source 167B. When the current from the IO module 140A approaches zero, the IO module 140A can disconnect itself from the terminals T1 and T2 via the switches 200A1 and 200B1, and the IO module 140B can then contribute to the full loop current. As a result, the engagement and disengagement of the IO module 140A can occur with minimal disruption to the processes implemented by the load 162. Note that the control system 170 can perform similar coordinated switching operations using the voltage generated by the voltage source 186. In this manner, one or more of the voltage sources 186A, 186B can also be varied to control whether the primary or secondary modules 140A, 140B “source” current and / or power.

[0084] As described above, IO modules 140 may sometimes be coupled to a shared load 162 that generates an analog signal, which IO modules 140 receive as an analog input (equivalently referred to herein as an analog input load). Figure 7 1 and 2. The IO module pair 140 is shown receiving analog current in parallel from a load 162 that supplies an analog input to the IO module 140. That is, Figure 7 FIG1 is a circuit diagram of IO module 140A and IO module 140B coupled in parallel and redundantly to a load 162 (e.g., a transducer), which generates an analog signal that is provided as an analog input signal to IO module 140. Load 162 is generally coupled to IO module 140 between terminals T1 and T2. Load 162 can provide an analog signal as an analog input signal to two of IO modules 140. For example, load 162 can include a 4 mA to 20 mA transducer that generates the analog signal.

[0085] Each IO module 140 can receive a portion of the total analog input from the load 162. The control system 170 can determine the proportion of the analog input received by each IO module 140 based on the voltage measured across the variable resistance device 169 (169A, 169B). Thus, when operating in analog input mode, the loop current provided by the load 162 is divided between the IO modules 140A and 140B, measured based on the voltage across the variable resistance devices 169A and 169B, and reported to the relative control systems 170A and 170B (or reported to a central control system), and summed by the respective control systems 170A and 170B to determine the total current provided by the load 162. To account for this, when the IO module 140A is removed from the circuit, the control system 170B can adjust the impedance of the variable resistance device 169B to match the previous impedance coupled to the load 162 when the IO module 140A was connected to the terminals. In other words, during a coordinated switchover, IO module 140A can disconnect itself from terminals T1 and T2, and IO module 140B can increase impedance before IO module 140A is removed to minimize disruption to the analog input current until the total loop current flows only through IO module 140B. When using analog inputs that support HART communication, it may be desirable to increase impedance before removing IO module 140A because the HART communication modem 190 expects inputs within an impedance range (e.g., corresponding to inputs at terminals T2 and / or T3). As a result of the impedance adjustment that occurs before removal, the input current reading reported to the control system 170A or 170B remains accurate, and disruptions are minimized or eliminated.

[0086] In operation, a respective control system 170 may sense a portion of the total analog input for its corresponding IO module 140 and add an indication of that portion to an indication of another portion of the total analog input to determine the total analog input. For example, control system 170A senses the analog input received by IO module 140A and transmits the measurement to control system 170B, which combines the measurement of control system 170A with its own measurement of the analog input received by secondary IO module 140B.

[0087] When operating in an analog input with a HART communication operating mode, such as when the load 162 includes a HART-compatible device, the conductor 164B connected to the terminal T2 can provide the analog input signal from the load 162 to the HART communication modem 190. The HART communication modem 190 can process the input analog signal separately for use by each control system 170. The conductor 164A connected to the terminal T1 can provide a return path to the load 162. In the input path (e.g., the channel coupled to the terminal T2), the control system 170 can control the variable resistance device 169 to adjust the resistance in the channel to facilitate HART operation.

[0088] As mentioned above, the shared load 162 may sometimes be a digital load. In fact, in addition to the analog IO load, Figure 5 The general purpose IO circuit can also be used to couple to one or more digital input loads and / or digital output loads. Figure 8 and Figure 9 An example digital load is shown in .

[0089] Now let's continue to discuss the digital IO circuit configuration of the general IO circuit. Figure 8 1 is a circuit diagram of a primary IO module 140A and a secondary IO module 140B coupled in parallel and redundantly to a load 162 to provide digital outputs to the load 162. In this example, the load 162 may be a digital load device including a digital logic state device 202 (202A, 202B), which may include a digital switch 220 and a current sensing device 222. The load 162 may be any suitable device that receives a digital output from the IO module 140. The digital switch 220 may include one or more redundant switches connected in series at terminal T2 to provide improved fault tolerance, improved disconnection or connection, improved availability (e.g., in situations where one switch no longer changes between open and closed), etc., compared to devices including fewer or no switches. The digital outputs here are two-wire outputs, but any suitable digital load that receives a digital signal to perform an operation (e.g., binary, high voltage, low voltage) may be used. The load 162 may include a digital actuator, such as an indicator light or a small motor. In some systems, an external power supply in series with the load 162 may be connected between terminals T2 and T3.

[0090] The control system 170 can control the switches 188 separately according to the needs of the digital devices. The control system 170A can generate a control signal and send it to the switch 188A, and the control system 170B can generate a control signal and send it to the switch 188B. The conductor 164A connected to the terminal T1 can provide this selectively transmitted digital signal to the load 162. The conductor 164B connected to the terminal T2 can provide a return path from the load 162 in a return channel (corresponding to the channel of the terminal T2) that is in line with the digital logic state device 202. In the return path (corresponding to the channel of the terminal T2), the control system 170 can control the digital logic state device 202 to minimize the resistance in the channel, such as by turning off the digital switch 220A, the digital switch 220B, or both to make the effective impedance become 0Ω, and thus allow the load 162 to receive a high voltage signal from the IO module 140.

[0091] In this digital output mode, digital switches 220A and 220B can function as redundant FET switches that are turned on and off to control the current through current sensing devices 222A and 222B, respectively, which can sense current. Control systems 170A and 170B can receive indications of the sensed current from current sensing devices 222A and 222B, respectively. Control systems 170A and 170B can turn digital switches 220A and 220B on and / or off, respectively.

[0092] In some embodiments, a separate parallel path coupled between terminals T2 and T3 can provide a digital output to a load also coupled to terminals T2 and T3. Figure 8 outside the path shown or as Figure 8 As an alternative to the path shown, such a separate parallel path may be provided between terminal T1 and terminal T2.

[0093] With the foregoing in mind, when operating in digital output mode, during normal operation, both I / O modules 140 can be coupled to terminals T1 and T2, and therefore to load 162, and output the same digital state (e.g., high voltage, low voltage, high current, low current, high impedance, low impedance). During coordinated switching, in one example, IO module 140A can disconnect itself from terminals T1 and T2 via switches 200A1, 200B1, or both. Since IO module 140B remains connected to terminals T1 and T2 and generates the same digital state as previously generated by IO module 140A, load 162 does not experience an interruption.

[0094] In addition to operating in digital output mode, IO module 140 may also operate in digital input mode such that shared load 162 may provide a digital input signal. Figure 9140B when coupled to a shared load 162 that provides digital signals to the IO module pair 140A, 140B. Figure 9 , the primary IO module 140A and the secondary IO module 140B can be coupled to the load 162 in parallel and redundantly to receive digital input signals from the load 162. The load 162 can be a digital load device including a resistor 224 and a switch 226. The switch 226 can generate a digital signal based on the position of the switch 226 (e.g., a digital high for a closed switch and a digital low for an open switch). The IO module 140 can receive a digital signal as a digital input. The digital signal can be an alarm signal, a signal indicating a measurement such as a temperature measurement, a voltage measurement, a current measurement, etc. In addition, the load 162 can provide a digital signal corresponding to an IEC Type 1, 2, or 3 digital sensor, such as a photoelectric sensor, a dry contact sensor, an inductive sensor, a button, a NAMUR sensor, etc.

[0095] By way of operation, for example, when IO modules 140A and 140B operate in digital input mode, IO modules 140A and 140B are both connected to terminals T1 and T2 during normal operation and read the same status from load 162 during normal operation. During coordinated switching operation, in one example, IO module 140A can disconnect itself from terminals T1 and T2 via switches 200A1, 200B1, or both. Since the remaining IO module 140B remains connected to terminals T1 and T2, devices that rely on digital input signals from load 162 can continue to operate based on the signals provided via IO module 140B. As a result, there is no interruption from the perspective of the input device.

[0096] With the foregoing in mind, the control system 170 can determine, based on the operating mode (e.g., analog input, analog output, digital input, digital output), to adjust the output signal, impedance, or other suitable characteristic from one or both of the IO modules 140. In the analog operating mode, the adjustment can balance the output signal (e.g., output power, output voltage, output current) from each of the IO modules 140 according to a set contribution amount (e.g., a 50% / 50% ratio), or can intentionally unbalance the output signal to a set contribution amount (e.g., a 60% / 40% ratio, a 30% / 70% ratio, a 0% / 100% ratio, an X% / Y% ratio, etc.) to perform coordinated switching operations.

[0097] Parallel operation can also be used to perform diagnostic operations. For example, the control system 170 can incrementally adjust an output signal by: making a change; testing a measured output value against a threshold; and making an additional change if the measured output value is greater than or less than a target threshold associated with verifying that the corresponding IO module 140 is capable of performing the requested operation. Sometimes, this adjustment can involve shifting a shared load 162 from being supplied by both IO modules 140 to being supplied by only one IO module 140. This can occur when the control system 170 is testing the power output capabilities of an IO module 140 or disconnecting an IO module 140 for maintenance and wishing to avoid disturbing the load. In practice, to do this, the control system 170 can perform coordinated switching to reduce the output signal from one IO module 140A, 140B at a rate that matches the rate used to increase the output signal from the other IO module 140B, 140A, where the coordinated switching can continue until the output signal from the IO module 140A, 140B has reached the target value. The respective rates used by the IO modules 140A, 140B can be inversely proportional to each other (e.g., 1 / X). Both IO modules 140 do not need to be aware that one of the IO modules 140 is going offline, and in some cases, the coordinated switchover is actively controlled by one of the IO modules 140 but automatically followed by the other IO module 140 .

[0098] In the event of an unexpected power outage of the primary IO module 140A, the primary IO module 140A can disconnect itself from the common terminal 166 to bring itself to a safe state. However, in the event of an unplanned power outage, the overall impact on the load 162 can be reduced by using the pair of parallel IO modules 140 because there are fewer switching transients associated with powering the load 162 rather than the secondary IO module 140B.

[0099] Taking the above into consideration, Figure 10140B to perform coordinated switching of a load 162 from being supplied by both the primary IO module 140A and the secondary IO module 140B to being supplied only by the secondary IO module 140B. The coordinated switching may be used to adjust the voltage output and / or current output of terminal T1 of each of the IO modules 140A and 140B. The process 240 is described as being performed by the control system 170A, and it should be understood that substantially similar operations may be performed by the control system 170, another control system associated with the distributed control system 48 (e.g., the IO module 98 (control)), and the like. These operations may be performed in response to processing circuitry of the control system 170A executing instructions stored in a tangible, non-transitory computer-readable medium, such as a memory of the control system 170A or another suitable memory. Furthermore, the operations of the process 240 are shown in a particular order; however, some of the operations may be performed in a different order than that generally presented or omitted. Certain voltage and current values are described herein, but it should be understood that these are example values and example ranges that may be adjusted for specific systems and implementations.

[0100] At block 242 , the control system 170A may receive an instruction to perform a coordinated switchover of the load 162 to the secondary IO module 140B. The instruction may correspond to the start of a diagnostic operation on the primary IO module 140A, to a user input indicating the initiation of a maintenance operation, a request to take the IO module 140A offline, etc. The control system 170A itself may trigger the generation of the instruction and / or one of the IO modules 98 may generate the instruction in response to a condition being met to trigger a diagnostic operation, in response to a user input, in response to an elapsed duration, in response to a fault detection, etc.

[0101] At block 244, the control system 170A may receive rate data. The rate data may define the rate at which the control system 170A reduces the current, voltage, impedance, or other circuit characteristics associated with the relationship between the primary IO module 140A, the secondary IO module 140B, and the load 162. The control system 170A may receive rate data input from an operator to the control system 170A, the IO module 98 (control), the primary IO module 140A itself, or the like. Different rates may be used for different types of device loads and / or IO patterns of the primary IO module 140A. For example, different loads may correspond to different rates of change to reduce the current used to transfer the load 162 to the secondary IO module 140B. The rate data may be stored in a memory and / or data structure. In some cases, the rate data may remain constant for different types of device loads and / or IO patterns of the primary IO module 140A.

[0102] At block 246, the control system 170A may adjust the circuit characteristics (e.g., current, voltage, impedance) supplied by the primary IO module 140A to the load 162 at a rate set by or based on the rate data, while the secondary IO module 140B adjusts the circuit characteristics it supplies to the load 162 at the rate to compensate for the loss of circuit characteristics provided by the IO module 140A. To do so, the control system 170A may reduce the current output from the primary IO module 140A at a rate based on the rate data associated with the instruction, and the control system 170B may increase the current output from the secondary IO module 140B at a matching rate. Adjusting the current output from either IO module 140A, 140B may include sending one or more commands to the current source 167, the variable resistor 169, the digital logic state device 202, the current sensing device 222, or similar current adjustment components of the IO modules 140A, 140B. One or more commands may adjust one or more impedances or characteristics of the device to adjust the current output from the IO modules 140A, 140B. For example, in one embodiment, the rate data may define the amount of current output from the IO module 140 over time (Δi / Δt), where the value of the current amount may repeatedly and incrementally decrease over time. The rate data may be transmitted to the control system 170B using any suitable means. For example, the control system 170A may transmit the rate data to the control system 170B, to the secondary IO module 140B, etc. The control system 170B may have the rate data stored in memory, or may receive the rate data from an operator input. In any case, the control system 170B may receive an instruction from the control system 170A, such as via the instructions in block 242 or by a separate instruction, to perform coordinated switching, and thereby operate to increase the current output of the second IO module 140B at a rate that matches the rate of the first IO module 140A. Matching the rate of decrease in the current supplied to load 162 with the rate of increase in the current supplied to load 162 can ensure that load 162 does not drop due to a lack of current or low current. The rate of decrease can be inversely proportional to the rate of increase. The current from master IO module 140A can continue to decrease until master IO module 140A supplies zero current to load 162.

[0103] To verify that zero current is being output from the master IO module 140A to the load 162, at block 248, the control system 170A may sense the current supplied by the master IO module 140A to the load 162 and determine at block 250 whether the supplied current is zero. One or more sensors may detect the current and / or voltage supplied to the load 162. The current may be determined by dividing the voltage supplied to the load 162 by a resistance that affects the current supplied to the load 162, which may include the resistance of the variable resistance device 169 when the voltage is measured. In some cases, to verify that zero current is being output, the control system 170A may determine whether the impedance of the master IO module 140A is equal to a threshold value. The threshold value may correspond to an impedance value known to result in zero current being output from the target IO module 140. The threshold value may be a resistance value, a capacitance value, an inductance value, or any combination thereof.

[0104] If it is determined at block 250 that the supplied current is not zero, the control system 170A may continue to reduce the current supplied at block 246 and may repeat the measurement of the current and / or voltage supplied to the load 162 at block 248. This may be repeated until the current supplied by the master IO module 140A is zero. When the current supplied by the master IO module is determined to be zero at block 250, the coordinated switching may be complete and the control system 170A may generate a control signal at block 252 to turn off the switches 200A1 to 200D1 of the master IO module 140A. Turning off the switches 200A1 to 200D1 may electrically decouple the master IO module 140A from the load 162, enabling maintenance or replacement of the master IO module 140A without disrupting the operation of the load 162, as the load is providing analog signals to or receiving analog signals from the IO module 140B. If the control system 170A performs a coordinated switching to test that the secondary IO module 140B can supply the full load current to the load 162, the control system 170A may not generate a control signal to open the switches 200A1 through 200D1. In this case, the control system 170A may generate an alarm and / or a control signal to notify the control system 170B that the load 162 has been switched and may begin a diagnostic of the current supplied by the secondary IO module 140B.

[0105] In some embodiments, processing circuitry, such as IO module 98, other upstream control circuitry, or one or more control systems 170, can receive instructions to perform coordinated switching of digital loads to one of the IO modules 140, such as switching a load from being coupled to both IO modules 140A and 140B to being coupled to secondary IO module 140B. In response to receiving the instructions, the processing circuitry can detect a first digital state of primary IO module 140A and a second digital state of secondary IO module 140B. In response to determining that the first and second digital states are the same, the processing circuitry can issue a command to close at least one switch of the first IO module 140A, thereby disconnecting the first IO module 140A from the load 162. After disconnecting the primary IO module 140A, the load 162 is connected to the secondary IO module 140B and not to the primary IO module 140A.

[0106] By providing the load 162 with parallel-coupled IO modules 140, data sent from or received by the load 162 is unlikely to be lost in the transition between using the IO modules 140 and the load 162 interface. For example, one of the IO modules 140 can receive output from the load 162 even when the other IO module 140 is offline, with minimal downtime or power loss. This can improve industrial automation system operation by providing more continuous visibility into output values relative to a system that may have had the output transmitted before a backup IO module was connected to the load 162, which may have missed changes to the output that were in progress when the backup IO module was connected. This data loss can be used to debug system operation and / or determine why the IO module 140 went offline in the first place. Thus, the operation and / or reliability of the industrial automation system can be improved by increasing visibility into the output from the load 162 to include visibility into the output even when switching the IO module 140 that is powering the load 162.

[0107] The diagnostic capabilities associated with upstream parallel and redundant power supplies can further improve industrial automation system operation by using the internal sensing circuitry of the IO power module to make it more likely that malfunctions can be detected early and the location of the fault can be more easily detected. In addition, IO modules with a universal IO configuration can provide additional benefits, such as providing a distributed control system that is less complex to maintain.

[0108] Note that in each of the above examples, load 162 is described as a two-wire load. However, it should be understood that similar or identical systems and methods can be applied to three or more wire loads. For example, load 162 can be coupled to IO module 140 via three or four wires, or any suitable number of wires.

[0109] The technical effects of the systems and methods described herein include using redundant and at least partially parallel IO modules with general IO circuits to supply shared loads. Although capable of operating independently, the redundant IO modules can be coupled to the shared load and supply a certain amount of signals to the shared load in parallel during normal operation. The proportion of the signals supplied to the shared load can be adjusted to perform diagnostic operations and / or in response to one of the modules becoming unavailable. In fact, by using these redundant and parallel IO modules described herein, industrial automation system operation can be improved by being able to interchangeably switch between primary and secondary IO modules without requiring sudden or abrupt switching operations, which can introduce switching transients and reduce the life of industrial automation components associated with the primary and secondary IO modules and / or the loads of the primary and secondary IO modules. In addition, by ensuring that the other IO module remains coupled to the load during coordinated switching, the redundant and parallel IO modules can increase visibility of the load output, even when the load is switched from the IO module supplying the load, thereby improving the operation and / or reliability of the industrial automation system.

[0110] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the present disclosure is not intended to be limited to the particular forms disclosed. Rather, the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0111] The technology presented and claimed herein is cited and applied to specific examples of material objects and practical properties that significantly advance the art and is therefore not abstract, intangible, or purely theoretical. Furthermore, if any claim appended hereto includes one or more elements designated as "means for [performing] [the function]..." or "a step for [performing] [the function]...", such elements are to be construed under 35 U.S.C. 112(f). However, for any claim containing an element designated in any other manner, such element is not to be construed under 35 U.S.C. 112(f).

Claims

1. A system comprising: a first input / output module configured to output a first current output, wherein the first input / output module is coupled to the first terminal and the second terminal; a second input / output module configured to output a second current output, wherein the second input / output module is coupled to the first terminal and the second terminal; a load device coupled to the first terminal and the second terminal, wherein the load device is configured to operate based on the first current output and the second current output; and One or more control systems configured to: receiving an instruction for performing a coordinated switch to the first input / output module; In response to receiving the instruction, sending a first command to the first input / output module to increase the first current output; and A second command is sent to the second input / output module to reduce the second current output.

2. The system according to claim 1, wherein: The one or more control systems are configured to: generating the first command to increase the first current output at a first rate based on rate data associated with the instruction; as well as The second command is generated to decrease the second current output at a second rate based on the rate data.

3. The system according to claim 2, wherein: The first rate is inversely proportional to the second rate.

4. The system according to claim 1, wherein: The one or more control systems are configured to send the first command to a first current source portion of the first input / output module.

5. The system according to claim 1, wherein The one or more control systems are configured to turn off at least one switch of the second input / output module after the first input / output module increases the first current output.

6. The system according to claim 1, wherein: The one or more control systems are configured to turn off at least one switch of the second input / output module after the second input / output module reduces the second current output to zero.

7. The system according to claim 1, wherein: The load device is configured to operate based on an amount of current received from the first input / output module, the second input / output module, or both.

8. The system according to claim 1, wherein: The first input / output module and the second input / output module are configured to provide the first current output and the second current output in parallel during normal operation.

9. The system according to claim 1, wherein: The load device is configured to be coupled to the first input / output module and the second input / output module via third and fourth terminals different from the first and second terminals.

10. A system comprising: a first input / output module configured to receive a first current input, wherein the first input / output module is coupled to a first terminal and a second terminal; a second input / output module configured to receive a second current input, wherein the second input / output module is coupled to the first terminal and the second terminal; a load device coupled to the first terminal and the second terminal, wherein the load device is configured to output the first current input and the second current input; and One or more control systems configured to: receiving an instruction for performing a coordinated switch to the second input / output module; generating a first command to adjust a first resistance of the first input / output module at a first rate based on rate data associated with the instruction; In response to receiving the instruction, sending the first command to the first input / output module to adjust a first resistance of the first input / output module; generating a second command to adjust a second resistance of the second input / output module at a second rate based on the rate data; and The second command is sent to the second input / output module to adjust a second resistance of the second input / output module.

11. The system according to claim 10, wherein: The first rate is inversely proportional to the second rate.

12. The system according to claim 10, wherein: The first command is configured to modify an impedance of a variable resistor of the first input / output module.

13. The system according to claim 10, wherein: The one or more control systems are configured to turn off at least one switch of the first input / output module after the first input / output module adjusts the first resistance.

14. The system according to claim 10, wherein: The one or more control systems are configured to turn off at least one switch of the first input / output module after the first resistance reaches a threshold resistance.

15. The system according to claim 10, wherein: The first input / output module and the second input / output module are configured to receive the first current input and the second current input, respectively, in parallel during normal operation.

16. The system according to claim 10, wherein: The load device is configured to be coupled to the first input / output module and the second input / output module via third and fourth terminals different from the first and second terminals.

17. A method comprising: receiving, via the processing circuit, an instruction to execute coordinated switching of a digital load device to a first input / output module, wherein the digital load device is coupled to the first input / output module and a second input / output module via at least two terminals; In response to receiving the instruction, detecting, via the processing circuit, a first digital state of the first input / output module; detecting, via the processing circuit, a second digital state of the second input / output module; and In response to determining that the first digital state and the second digital state are the same, a command is sent via the processing circuit to close at least one switch of the second I / O module, thereby disconnecting the second I / O module from the digital load device.

18. The method according to claim 17, wherein The digital load device is configured to send an alarm signal and / or a signal indicating a measurement result to the first input / output module, the second input / output module, or both.

19. The method according to claim 17, wherein The digital load device is configured to receive an alarm signal and / or a signal indicating a measurement result from the first input / output module, the second input / output module, or both.

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