Patent Publication Number: US-7917857-B2

Title: Direct subscription to intelligent I/O module

Description:
TECHNICAL FIELD 
     The subject innovation relates generally to historian components associated with industrial units, and more particularly to a direct subscription of subscribers to historians of the industrial unit (e.g., bypassing the controller). 
     BACKGROUND 
     Industrial controllers are special-purpose computers utilized for controlling industrial processes, manufacturing equipment, and other factory automation, such as data collection or networked systems. At the core of the industrial control system, is a logic processor such as a Programmable Logic Controller (PLC) or PC-based controller. Programmable Logic Controllers for instance, are programmed by systems designers to operate manufacturing processes via user-designed logic programs or user programs. The user programs are stored in memory and generally executed by the PLC in a sequential manner although instruction jumping, looping and interrupt routines, for example, are also common. Associated with the user program are a plurality of memory elements or variables that provide dynamics to PLC operations and programs. Differences in PLCs are typically dependent on the number of Input/Output (I/O) they can process, amount of memory, number and type of instructions, and speed of the PLC central processing unit (CPU). 
     In a more macro sense than the controller, businesses have become more complex in that higher order business systems or computers often need to exchange data with such controllers. For instance, an industrial automation enterprise may include several plants in different locations. Modern drivers such as efficiency and productivity improvement, and cost-reduction, are requiring manufacturers to collect, analyze, and optimize data and metrics from global manufacturing sites. For example, a food company can have several plants located across the globe for producing a certain brand of food. These factories in the past were standalone, with minimum data collection and comparison of metrics with other similar factories. In the networked world of today, manufacturers are demanding real-time data from their factories to drive optimization and productivity. Unfortunately, conventional control systems architectures are not equipped to allow a seamless exchange of data between these various components of the enterprise. 
     Another requirement of modern control system architectures is the ability to record and store data in order to maintain compliance with Food and Drug Administration regulations such as Regulation 21 CFR Part 11. One common solution for recording data includes providing a local recording module that often occupies a slot in a controller backplane such as a PC-Historian which is an industrial computer for the controller backplane, and employs a transitional layer to supply an indirect interface to the controller. This includes a platform that provides high speed, time series, data storage and retrieval with both local and remote control processors. The PC-Historian communicates with controllers directly through the backplane and can communicate remotely via a network interface. The PC-Historian allows archiving data from the controller to an Archive Engine which provides additional storage capabilities. 
     In general, industrial controllers are constructed in modular fashion to accommodate different applications requiring various numbers and types of input/output (I/O) circuits, as is determined by the particular device or process being controlled. The stored control program runs in real-time to provide outputs to the controlled process (e.g., electrical signals to outputs such as actuators and the like.) Accordingly, such controllers typically only deal with current value of data—as opposed to leveraging from data trends that are available to I/O modules associated with industrial units. Moreover, such controllers can become overloaded when a plurality of users simultaneously request data. 
     SUMMARY 
     The following presents a simplified summary in order to provide a basic understanding of some aspects described herein. This summary is not an extensive overview nor is intended to identify key/critical elements or to delineate the scope of the various aspects described herein. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
     The subject innovation provides for systems and methods of directly subscribing subscribers/users to the I/O module for obtaining data (e.g., bypassing the controller) via employing a subscription and notification component. Such subscription and notification component enables inputs and outputs to be recorded in an I/O table in processor memory. Such input values can be asynchronously read from one or more input modules and output values written to the I/O table for subsequent communication to users by specialized communications circuitry (e.g., back plane interface, communications module.) In a related aspect, users can consume such data directly, typically without a controller involved in the process, wherein data internal to the I/O can be historized and be directly available to the users. The I/O module can further include a publishing component that can publish data, which is stored in the I/O on the network, and a memory medium for storing historized data. The I/O module can further include a point to point closure therein, and allow for high speeds and publishing of diagnostic data regarding proper operation of the industrial unit that the I/O is associated with. 
     In a related aspect, the subscriber information (as well as event information if desired) can be abstracted to high-level classes (e.g., data fields), which can provide for modeling notification related information when querying and requesting information from the historians. Subscription applications can thus be developed at high levels, wherein complex subscription queries and subscriber information can be defined as data fields, for example. Historians associated with such data fields can be propagated with subscription/subscriber specific information. By modeling the notification related information (e.g., subscription queries, subscriber information, event information . . . ) as data and leveraging the power of database systems to perform set-oriented manipulations on this data efficiently, the subject innovation enables for a highly scalable and efficient subscription and notification system. 
     In a related aspect, a locator component can facilitate discovery of history data that is associated with a plant historian of an industrial programmer (e.g., a controller device.) The locator component can further detect embedded historians that are distributed on the back plane of an industrial network. In general, such embedded historians (unlike conventional PC historians) supply a direct interface to controllers without employing a transitional layer, and hence provide a substantially higher data exchange rate as compared to conventional PC historians. The locator component can be part of applications running on a control unit, which can function as a management control center for the industrial network system. 
     According to a further aspect of the subject innovation, the locator component can define type of historian data to be automatically located and collected from the embedded historians, and further assigns type of historian data to be collected by such embedded historians. For example, the locator component can employ a trail of metadata to identify the embedded historians and relevant historian data for collection. Additionally, a polling/publication arrangement can also be employed wherein the embedded historians (e.g., microhistorians) identify themselves to the locator component upon occurrence of a predetermined event, and/or periodically. 
     As such, a distributed and scalable framework can be provided, which enables data historian functionality to be efficiently incorporated at various levels of an enterprise. For example, from lower control levels of a plant, to middle tiers of the plant (which collect data from the lowest levels) and from enterprise levels that aggregate data from such lower and middle levels, the embedded historian components can interact with a locator component, to facilitates data collection across an organizational hierarchy. Such framework can employ a directory and location service to enable configuration of embedded historians and to allow automated integration at the various levels of the organization. 
     In a related methodology in accordance with an aspect of the subject innovation, users can initially determine type of data to be collected. The locator component is then notified for collection of such data type. Next, the locator component can locate embedded historians that have collected or have access to a collection of determined data type. Subsequently, the data can be acquired, supplied and reported to the user who directly subscribes to the historians. 
     To the accomplishment of the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and the annexed drawings. These aspects are indicative of various ways which can be practiced, all of which are intended to be covered herein. Other advantages and novel features may become apparent from the following detailed description when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a schematic block diagram for a subscription/notification component that supplies direct subscription of users with a historian component and bypassing controllers, to supply historian data in accordance with an aspect of the subject innovation. 
         FIG. 2  illustrates a locator component that is associated with a plant embedded historian network of an industrial programmer system. 
         FIG. 3  illustrates a system that includes a plurality of embedded historians operating in an organizational data model. 
         FIG. 4  illustrates a notification component that is operatively connected to an embedded historian network. 
         FIG. 5  illustrates an exemplary industrial automation network that employs a subscription and notification component that is associated with an embedded historian network. 
         FIG. 6  illustrates an exemplary multi-tiered and distributed historian system, which enable direct subscription to users for access to historian data. 
         FIG. 7  illustrates historian services that include historian data services and presentation and reporting services. 
         FIG. 8  illustrates a related methodology of supplying data collected via embedded historians to subscribers in accordance with an exemplary aspect of the subject innovation. 
         FIG. 9  illustrates a related methodology of supplying data to subscribed users and data collection, via a plurality of embedded historians that are locatable thru the locator component. 
         FIG. 10  illustrates an exemplary system that can employ a notification and subscription component in accordance with an aspect of the subject innovation. 
     
    
    
     DETAILED DESCRIPTION 
     The various aspects of the subject innovation are now described with reference to the annexed drawings, wherein like numerals refer to like or corresponding elements throughout. It should be understood, however, that the drawings and detailed description relating thereto are not intended to limit the claimed subject matter to the particular form disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claimed subject matter. 
       FIG. 1  illustrates an industrial system  100  that facilitates delivery of information to subscribers  112 ,  114 ,  116  that have subscribed to distributed embedded historians  115 , in accordance with an aspect of the subject innovation. The subscription and notification component  110  enables inputs and outputs to be recorded in an I/O table in processor memory, wherein input values can be asynchronously read from one or more input modules and output values written to the I/O table for subsequent communication to users by specialized communications circuitry (e.g., back plane interface, communications module.) In a related aspect, users can consume such data directly, typically without a controller involved in the process, wherein data internal to the I/O can be historized and be directly available to the users. The I/O module can include a publishing component that can publish data that is stored in the I/O on the network, and a memory medium for storing the historized data. The I/O module can further include a point to point closure therein, to allow for high speeds and publishing of diagnostic data regarding the health/operation of the industrial unit that the I/O is associated with. 
     The system  100  provides for high-scalability and affords for disseminating information to subscribers  112 ,  114 ,  116  (1 thru L, L being an integer) according to specific subscriber preferences (e.g., form of display, notifications, and the like.) Such subscriber can be in form of an entity (e.g., a person or application) that has subscribed to the industrial system  100 . A subscription in accordance with the subject innovation can be an expressed interest in certain information (e.g., manufacturing data, processing data and other historian data), and the specification of a delivery mode (e.g., e-mail, voice mail, delivery via PDA, desktop computer, cellular telephone, television, and the like). 
     In a related aspect, the subscription and notification component  110  provides for dynamically modifying deliver modes given the type of information requested from the distributed historian(s)  115  and that is to be delivered, the criticality associated with the information, the subscriber&#39;s present state, and the deliver preferences given other parameters, and the like. Accordingly, the system  100  providing such highly scalable notification services is the employment of modeling subscriptions as data. Information that subscribers are interested in can be collected as events. Various subscription classes can then be defined for type of data and notifications that are to be provided. 
     Hence, the subscriber information (as well as event information if desired) can be abstracted to high-level classes (e.g., data fields), which can provide for modeling notification related information when querying and requesting information from the historians. Subscription applications can thus be developed at high levels, wherein complex subscription queries and subscriber information can be defined as data fields for example. Historians in accordance with the data fields can be propagated with subscription/subscriber specific information. By modeling the notification related information (e.g., subscription queries, subscriber information, event information . . . ) as data and leveraging the power of database systems to perform set-oriented manipulations on this data efficiently, the subject innovation enables a highly scalable and efficient subscription and notification system. 
       FIG. 2  illustrates a locator component  210  that is associated with a plant embedded historian network of an industrial programmer system  200  (e.g., a network of controller devices), to facilitate discovery of history data and transferring to subscribers  242 ,  244 ,  246 , with direct access thereto (e.g., bypassing the controllers.) Such locator component  210  can further detect embedded historians that are distributed on the back plane of an industrial network. The locator component  210  can be part of applications running on a control unit, which can function as a management control center for the industrial network system  200 . Accordingly, a distributed embedded historian framework is provided, wherein historical data types  212 ,  214 ,  216  (1 thru m, m being an integer) can be collected in accordance with an organizational model of a hierarchical system that is distributed across various elements of an enterprise. Such an arrangement enables data identified for historian purposes to be automatically collected and also allows embedded historian functionality to be exposed and thus efficiently integrated with other elements of an organization. These elements can include representations of the system that are maintained on higher-level business servers and other representations that serve control elements of the system such as programmable logic controllers and/or other industrial control components (e.g., sensors, modules, and the like), for example. As explained in detail infra, a directory service (not shown) can further operate with the organizational model to enable configuration of embedded historians within the organization, and to enable data types  212 ,  214 , and  216  to be located within the organization for transfer directly to the subscriber  242 ,  244 ,  246 . 
     For example, common organization functionality such as security services can be distributed to the embedded historians  221 ,  222 ,  223  according to the data model and directory service, wherein the common data model then exposes functionality and data of the organization to the distributed embedded historians  221 ,  222 ,  223 . In contrast to conventional PC historians, embedded historians (e.g., micro historians) of the subject innovation are special purpose historians that reside in a backplane and supply direct interface (e.g., without a transition layer) to controllers and/or associated industrial units. Such embedded historians employ industrial specifications (e.g., regarding shock vibration, sealing, contamination proofing, and the like), and supply substantially higher data exchange speed as compared to conventional PC historians. A network system (not shown) can be associated with the industrial automation system  200 , which can be searched via the locator component  210 . The network system can further include additional hosts (not shown), which may be personal computers, servers or other types of computers. Such hosts generally can be capable of running or executing one or more application-level (or user-level) programs, as well as initiating an I/O request (e.g., I/O reads or writes). In addition, the network system can further include one or more input/output units (I/O units), wherein such I/O units can includes one or more I/O controllers connected thereto, and each of the I/O can be any of several types of I/O devices, such as storage devices (e.g., a hard disk drive, tape drive) or other I/O device. The hosts and I/O units and their attached I/O controllers and devices can be organized into groups such as clusters, with each cluster including one or more hosts and typically one or more I/O units (each I/O unit including one or more I/O controllers). The hosts and I/O units can be interconnected via a collection of routers, switches and communication links (such as wires, connectors, cables, and the like) that connects a set of nodes (e.g., connects a set of hosts and I/O units) of one or more clusters. 
       FIG. 3  illustrates a system  300  that includes a plurality of embedded historian components  310  operating in an organizational data model, wherein a locator component  309  can detect embedded historians (e.g., micro historians) that are distributed on the back plane of an associated industrial network, to facilitate subscriptions thereof. In addition, the embedded historian components  310  can be distributed across a network  314  to provide a collective or distributed database. The locator component  309  can be part of applications running on a control unit  330 , which can function as a management control center for the industrial network system. 
     The industrial setting or organizational enterprise  300  can employ a plurality of computers or network components that communicate across the network  314 , to one or more industrial control components  330 , such as for example programmable logic controllers (PLCs)  311 ,  312 ,  313  (1 to j, j being an integer) or other factory components. Thus, the embedded historian components  310  can be operated as a singular or collective entity while being viewed, managed and distributed across substantially all or portions of the enterprise  320 , control component  330  and/or locator component  309 . For example, at the control levels  330 , embedded historians can be embedded within a PLC rack to collect data, whereas higher levels at  320  can be employed to aggregate data from lower levels. Such can include higher level software components that communicate across the network  314  to collect data from lower level control components. The network  314  can include public networks such as the Internet, Intranets, and automation networks such as Control and Information Protocol (CIP) networks including DeviceNet and ControlNet. Other networks include Ethernet, DH/DH+, Remote I/O, Fieldbus, Modbus, Profibus, wireless networks, serial protocols, and the like. In addition, the network devices can include various possibilities (hardware and/or software components). These include components such as switches with virtual local area network (VLAN) capability, LANs, WANs, proxies, gateways, routers, firewalls, virtual private network (VPN) devices, servers, clients, computers, configuration tools, monitoring tools, and/or other devices. 
     Likewise, the industrial/enterprise  320  can include various computer or network components such as servers, clients, communications modules, mobile computers, wireless components, and the like which are capable of interacting across the network  314 . Similarly, the term PLC as used herein can include functionality that can be shared across multiple components, systems, and/or networks  314 . For example, one or more PLCs of the control component  330  can communicate and cooperate with various network devices across the network  314 . Such can include substantially any type of control, communications module, computer, I/O device, sensor, Human Machine Interface (HMI) that communicate via the network  314  which includes control, automation, and/or public networks. The PLC  330  can also communicate to and control various other devices such as Input/Output modules including Analog, Digital, Programmed/Intelligent I/O modules, other programmable controllers, communications modules, and the like. 
     The system  300  enables combining organizational information such as an organizational or hierarchical data model which represents a common model of a plant that can be based in the S88 or S95 model, and is distributed among computers of the enterprise  320  and industrial controllers  330 , for example. The model can be viewed as an Organizational Data Model—a tree-like hierarchical and heterogeneous structure of organizational Units. For instance, respective Organizational Units can include other Organizational Units. Organizational Units can be either physical locations (e.g., Site, Area) or logical grouping node or collection (e.g., Enterprise as a collection of Sites). The nodes in the organizational hierarchy or model can have associated items representing the plant&#39;s production and control equipment, tags, backing tags (e.g., Alarm &amp; Event and the like), programs, equipment phases, I/O devices, and other application related entities. These organizational units thus can form an application view of the user&#39;s system. 
     A typical system  300  can assign the upper levels of the hierarchy such as an Enterprise node and site to a computer system and the lower levels such as area, line, cell and machine can be contained in multiple industrial controllers  330 ; each of which can include components that are members of one or more organization units such as area or area model. Moreover, an organization unit can contain components from one or more controllers. The embedded historian component  310  can be positioned at various levels of the enterprise  320  and/or control  330 ; and can also further be integrated therein and scaled according to system data collection requirements. Such organizational model enables embedded historian components  310  to locate data of interest for collection purposes and to readily adapt and become integrated within the larger system  300 . 
     Adaptability within the system  300  can be facilitated by data having additional information such as metadata that identifies the purpose of the data. Such metadata can further be employed by the locator component  309  to identify a micro-historian. For example, the locator component  309  can employ a trail of metadata to identify the embedded historians and relevant historian data for collection 
     Accordingly, one form of data can identify itself as a control tag that has been marked or labeled via metadata to indicate its significance for data collection purposes. Another type of label or metadata can indicate security information that is being distributed throughout the system  300 . Furthermore, other type of data can indicate that an alarm condition or an event has occurred within the system and thus, a respective embedded historian component should capture such alarm or event. In general, the organizational model enables embedded historian components  310  to receive functionality or data context from the system  300  and to expose its respective functionality to the system via the model. For example, context allows embedded historian components to such auto configuration routines where one or more components of the embedded historian architecture can be automatically discovered and configured onto a respective system. Hence, the embedded historian components  310  and the locator component  309  can be automatically integrated within the system  300 , to further facilitate scaling of the system as data conditions change. 
     In a related aspect, such scaling can include the ability of one or more components of an organization to collaborate, and provide an overall scheme for historical data collection. Such can include having lower level PLCs or factory components collecting data and sharing this data with higher levels of the organization. If one or more of the levels become overloaded with the data collection process, historian functionality can be shifted between levels (upwards or downwards) to more effectively employ system-wide resources in an efficient manner. For instance, communications between levels can allow sharing of data collection responsibilities between one or more levels of the enterprise from the very lowest levels through the higher levels of the organizational hierarchy. 
     For example, the lowest level entity can have sufficient memory for data collection of desired embedded historian or archived information. If such memory resources are consumed, messaging capabilities throughout the hierarchy can subsequently take over to distribute storage responsibilities from one layer to another via suitable network messages (wireless or wired) that communicate data from one level to another. It is to be appreciated that tiers of an organization can collaborate in many combinations. Thus, a high level tier could collaborate with a low level tier or collaboration can take place between multiple tiers if desired such as between higher levels, intermediate levels, and lower levels of an organization. 
     The locator component  309  can identify embedded historians (e.g., micro-historians), and notify them to collect various data types. The locator component  309  can subsequently locate embedded historians that have collected or have access to a collection of such data types. Next, the data can be acquired, supplied and reported to the user via a plurality of interfaces. Such interfaces can be supplied to manipulate the embedded historian components  310  and organizational data model; such as a Graphical User Interface (GUI) to interact with the model or other components of the hierarchy; e.g., as any type of application that sends, retrieves, processes, and/or manipulates factory or enterprise data, receives, displays, formats, and/or communicates data, and/or facilitates operation of the enterprise  320  and/or PLCs  330 . For example, such interfaces can also be associated with an engine, server, client, editor tool or web browser although other type applications can be utilized. 
       FIG. 4  illustrates a notification component  425  that is operatively connected to embedded historian network  400  to facilitate a direct subscription in accordance with an aspect of the subject innovation. The industrial setting  405  can employ a hierarchical data model with various levels; e.g., enterprise level, site level (factory represented within a data packet), area level (an area within the factory associated with the data); line level (a line associated with particular data), a work-cell level (that indicates a work-cell associated with the data) and the like. For example by employing a nested, hierarchical data model, embedded historian components  400  can readily become aware of data associated therewith. Furthermore, such hierarchy can further be customized by users to obtain increased granularity within the hierarchy. The common plant model can enable the embedded historian component  400  to determine data contexts in an automated manner. The common data model  410  allows data to be marked or labeled via metadata for example to both expose embedded historian functionality to a system and/or to allow the embedded historian component  400  to be automatically integrated within the system according to data that is exposed to the embedded historian component. For example, one such labeling can pertain to security, and typically can affect substantially all components in the system associated with the common model  410 . 
     The notification component  425  can be associated with a directory and discovery service  420 . Such an arrangement enables the embedded historian component  400  to locate other embedded historian components in the system and to receive/expose historian data to other system components. This can include a network directory that determines physical addresses from logical names and vice versa, for example. Moreover, the publish and subscribe component  430  can provide subscription functionality to the embedded historian component  400 , wherein data collection efficiency of the system can be enhanced. For example, the publish and subscribe component  430  of the system  405  allows data to be published or generated when a change in the data has been detected. Thus, the embedded historian component  400  can subscribe to such change events and thus only record data when a change has occurred which reduces the amount of data to be stored. Furthermore, the notification component  425  can employ a trail of metadata to identify the micro-historians and relevant historian data for collection. Additionally, a polling/publication arrangement can also be employed wherein the embedded historians (e.g., micro-historians) identify themselves to the locator component upon occurrence of a predetermined event, and/or periodically. 
       FIG. 5  illustrates an exemplary industrial automation network  500  that employs a subscription and notification component  543  that is associated with an embedded historian component  533  to enable direct subscription for users to the I/O module for obtaining direct data, and bypassing controllers. The industrial setting  500  can include a database  510 , a human machine interface (HMI)  520  and a programmable logic controller (PLC)  530 , and a directory interface  540 . 
     The directory interface  540  can further associate with an Artificial Intelligence (AI) component  550  to facilitate efficient identification of desired data for various subscribers within a particular network/application. The directory interface  540  can be employed to provide data from an appropriate location such as the data source  560 , a server  570  and/or a proxy server  580 . Accordingly, the directory interface  540  can point to a source of data based upon role and requirements (needs) of a requester (e.g., database  510 , HMI  520 , PLC  530 , and the like.) The database  510  can be any number of various types such as a relational, network, flat-file or hierarchical systems. Typically, such databases  510  can be employed in connection with various enterprise resource planning (ERP) applications that can service any number of various business related processes within a company. For example, ERP applications can be related to human resources, budgeting, forecasting, purchasing and the like. In this regard, particular ERP applications may require data that has certain desired attributes associated therewith. Thus, in accordance with an aspect of the subject invention, the directory interface  540  can provide data to the database  510  from the server  570 , which provides data with the attributes desired by the database  510 . 
     As illustrated in  FIG. 5 , the embedded historian  533  can leverage directory interface  540  and other software services, or re-locatable information services and the like, to locate other embedded historian components and their configurations, via the subscription and notification component  543  of the subject innovation. Such subscription and notification component  543  can further be associated with a locator component (not shown) that can further detect embedded historians  533  that are distributed on the back plane of an industrial network. The locator component  560  can be part of applications running on a control unit, which can function as a management control center for the industrial network system. 
     Moreover, the HMI  520  can employ the directory interface  540  to point to data located within the system  500 . The HMI  520  can be employed to graphically display various aspects of a process, system, factory, etc. to provide a simplistic and/or user-friendly view of the system. Accordingly, various data points within a system can be displayed as graphical (e.g., bitmaps, jpegs, vector based graphics, clip art and the like) representations with desired color schemes, animation, and layout. 
     The HMI  520  can request data to have particular visualization attributes associated with data in order to easily display such data thereto. For example, the HMI  520  can query the directory interface  540  for a particular data point that has associated visualization attributes. The directory interface  540  can determine the proxy server  580  contains the attributed data point with the desired visualization attributes. For instance, the attributed data point can have a particular graphic that is either referenced or sent along with the data such that this graphic appears within the HMI environment instead of or along with the data value. 
     As explained earlier, the PLC  530  can be any number of models such as Allen Bradley PLC5, SLC-500, MicoLogix, and the like. The PLC  530  is generally defined as a specialized device employed to provide high-speed, low-level control of a process and/or system. The PLC  530  can be programmed using ladder logic or some form of structured language. Typically, the PLC  530  can utilize data directly from a data source (e.g., data source  560 ) that can be a sensor, encoder, measurement sensor, switch, valve and the like. The data source  560  can provide data to a register in a PLC and such data can be stored in the PLC if desired. Additionally, data can be updated (e.g., based on a clock cycle) and/or output to other devices for further processing. 
       FIG. 6  illustrates an exemplary multi-tiered and distributed historian system  600 , which can allow direct subscription to users for access to historian data in accordance with an aspect of the subject innovation. The exemplary system  600  illustrates three tiered historian level, wherein the highest data collection tier is illustrated and can be referred to as the enterprise tier  610 . This tier aggregates data collected from lower level tiers such as from a plant tier  620  and a micro or embedded tier  630 . As illustrated, the tiers  610  and  620  can include archival or permanent storage capabilities. In the system  600 , data can be collected from two plants at the tier  620 , and from a plurality of historian components at tier  630 . It is to be appreciated that such an arrangement is exemplary in nature, and other arrangements are well within the realm of the subject innovation. 
     Typically, the system  600  can be viewed as a Distributed Historian that spans machines, plants, and enterprises. At level  630 , the historian collects data at the rack level and is coupled to Common Plant Data Structure described above. Such can include collecting process &amp; discrete data, alarms &amp; events in a single archive if desired. Other aspects can include auto-discovery of data and context from controllers in local chassis including store/forward data capabilities from local buffers. Data can be collected without polling, having a low communications bandwidth. The plant level  620  aggregates data from Micro or rack-embedded Historians and/or other data sources (e.g., Live Data source). Such can include plant-level querying, analytics, reporting while efficiently storing, retrieving, and managing large amounts of data. This level can also auto-discover data and data model context from Micro Historians located at level  630 . Other features of the system  600  can include analysis components, logical units, components for interaction with report elements, embeddable presentation components, replication of configuration, storage, archiving, data compression, summarization/filtering, security, and scalability. 
       FIG. 7  illustrates historian services  700  that include historian data services  710  and presentation and reporting services  720 . Historian Data Services  710  (HDS) can supply generic, customizable services for collecting and storing data with plant model-defined context. This can include configuration of data to be collected e.g., tags, data context, alarms, events, diagnostics, SOE data and configuration of data to be forwarded to a higher level. Collection of data can be from disparate sources including storage of data, retrieval of data, and management of data. Management of data collected by/residing in other data stores (e.g., higher-level business systems, 3rd party products) can be processed by the respective applications. The presentation and reporting services  720  (PRS) can supply generic, customizable services for collating and presenting data in a common plant model-defined context. This can include access to stored data, analysis/calculators and query mechanisms, and embeddable, interactive presentation components (e.g., text, charts, SPC). The service  710  can generate reports with various means of presentation/distribution (e.g., web, email) having export capabilities to standard formats (e.g., XML, Excel). 
       FIG. 8  illustrates a related methodology  800  of supplying data collected via embedded historians to subscribers in accordance with an exemplary aspect of the subject innovation. While the exemplary method is illustrated and described herein as a series of blocks representative of various events and/or acts, the present invention is not limited by the illustrated ordering of such blocks. For instance, some acts or events may occur in different orders and/or concurrently with other acts or events, apart from the ordering illustrated herein, in accordance with the invention. In addition, not all illustrated blocks, events or acts, may be required to implement a methodology in accordance with the present invention. Moreover, it will be appreciated that the exemplary method and other methods according to the invention may be implemented in association with the method illustrated and described herein, as well as in association with other systems and apparatus not illustrated or described. Initially and at  810 , users can initially determine type of data to be collected. Subsequently, and at  820  the locator component is notified for collection of such data type. The locator component can then locate embedded historians that have collected or have access to a collection of such data type, at  830 . Subsequently, the data can be acquired, supplied and reported to the subscribers at  840 , and hence bypass the controllers. 
       FIG. 9  illustrates a related methodology  900  of supplying data to subscribed users and data collection, via a plurality of embedded historians that are locatable through the locator component. Initially, and at  910 , subscribers can directly subscribe to historians, and hence bypass other components (e.g., controllers) for access to historian data in accordance with an aspect of the subject innovation. Next and  920 , the locator component can employ trail of data to locate a desired embedded historian. Such can further include employing a directory to determine where the source or destination for a particular embedded historian data structure is located. At  930 , embedded historian functionality can be associated with the common data structure, wherein the controller can specify that such data is to be collected by an embedded historian component. Similarly, data can be exposed to embedded historian components according to its metadata or other determined data context. At  940 , embedded historian data is collected across various levels of an organization according to the plant data model and via the associated directory service, for display to subscribers. 
     In order to provide context for the various applications in which the aspects of the innovation may be carried out, an exemplary system that can employ a notification and subscription component is illustrated in  FIG. 10 . However, it will be appreciated that the various aspects of the innovation may be employed in association with controllers and control systems other than those illustrated and described herein. As illustrated, each functional module  1014 , is attached to the backplane  1016  by means of a separable electrical connector  1030  that permits the removal of the module  1014  from the backplane  1016  so that it may be replaced or repaired without disturbing the other modules  1014 . The backplane  1016  provides the module  1014  with both power and a communication channel to the other modules  1014 . Local communication with the other modules  1014  through the backplane  1016  is accomplished by means of a backplane interface  1032  which electrically connects the backplane  1016  through connector  1030 . The backplane interface  1032  monitors messages on the backplane  1016  to identify those messages intended for the particular module  1014 , based on a message address being part of the message and indicating the message destination. Messages received by the backplane interface  1032  are conveyed to an internal bus  1034  in the module  1014 . 
     The internal bus  1034  joins the backplane interface  1032  with a memory  1036 , a microprocessor  1028 , front panel circuitry  1038 , I/O interface circuitry  1039  and communication network interface circuitry  1041 . The microprocessor  1028  can be a general purpose microprocessor providing for the sequential execution of instructions included within the memory  1036  and the reading and writing of data to and from the memory  1036  and the other devices associated with the internal bus  1034 . The microprocessor  1028  includes an internal clock circuit (not shown) providing the timing of the microprocessor  1028  but may also communicate with an external clock  1043  of improved precision. This clock  1043  may be a crystal controlled oscillator or other time standard including a radio link to an external time standard. The precision of the clock  1043  may be recorded in the memory  1036  as a quality factor. The panel circuitry  1038  includes status indication lights such as are well known in the art and manually operable switches such as for locking the module  1014  in the off state. 
     The memory  1036  can comprise control programs or routines executed by the microprocessor  1028  to provide control functions, as well as variables and data necessary for the execution of those programs or routines. For I/O modules, the memory  1036  may also include an I/O table holding the current state of inputs and outputs received from and transmitted to the industrial controller  1010  via the I/O modules  1020 . The module  1014  can be adapted to perform the various methodologies of the innovation, via hardware configuration techniques and/or by software programming techniques. 
     It is noted that as used in this application, terms such as “component,” “hierarchy,” “model,” and the like are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution as applied to an automation system for industrial control. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program and a computer. By way of illustration, both an application running on a server and the server can be components. One or more components may reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers, industrial controllers, and/or modules communicating therewith. 
     What has been described above includes various exemplary aspects. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing these aspects, but one of ordinary skill in the art may recognize that many further combinations and permutations are possible. In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure, which performs the function in the herein illustrated exemplary aspects of the innovation. In this regard, it will also be recognized that the innovation includes a system as well as a computer-readable medium having computer-executable instructions for performing the acts and/or events of the various methods of the innovation. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.