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Data Historian
Operational historian refers to a complementary set of time-series database applications that are developed for operational process data. Historian software is often embedded or used in conjunction with standard DCS and PLC control systems to provide enhanced data capture, validation, compression, and aggregation capabilities. Historians have been deployed in almost every industry and contribute to functions such as supervisory control, performance monitoring, quality assurance, and, more recently, machine learning applications which can learn from vast quantities of historical data. These systems were originally developed to capture instrumentation and control data, which led many to use the term "tag" for a stream of process data, referring to the physical "tags" which had been placed on instrumentation for manually capturing data. Raw data may be accessed via OPC HDA, SQL, or REST API interfaces.{{cite web, url= https://www.parasyn.com.au/operational-historian-vs-enterprise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Series Database
A time series database (TSDB) is a software system that is optimized for storing and serving time series through associated pairs of time(s) and value(s). In some fields, ''time series'' may be called profiles, curves, traces or trends. Several early time series databases are associated with industrial applications which could efficiently store measured values from sensory equipment (also referred to as data historians), but now are used in support of a much wider range of applications. In many cases, the repositories of time-series data will utilize compression algorithms to manage the data efficiently. Although it is possible to store time-series data in many different database types, the design of these systems with time as a key index is distinctly different from relational databases which reduce discrete relationships through referential models. Overview Time series datasets are relatively large and uniform compared to other datasets―usually being composed of a timestamp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Control System
A distributed control system (DCS) is a computerised control system for a process or plant usually with many control loops, in which autonomous controllers are distributed throughout the system, but there is no central operator supervisory control. This is in contrast to systems that use centralized controllers; either discrete controllers located at a central control room or within a central computer. The DCS concept increases reliability and reduces installation costs by localising control functions near the process plant, with remote monitoring and supervision. Distributed control systems first emerged in large, high value, safety critical process industries, and were attractive because the DCS manufacturer would supply both the local control level and central supervisory equipment as an integrated package, thus reducing design integration risk. Today the functionality of Supervisory control and data acquisition (SCADA) and DCS systems are very similar, but DCS tends to be u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Logic Controller
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity that requires high reliability, ease of programming, and process fault diagnosis. Dick Morley is considered as the father of PLC as he had invented the first PLC, the Modicon 084, for General Motors in 1968. PLCs can range from small modular devices with tens of inputs and outputs (I/O), in a housing integral with the processor, to large rack-mounted modular devices with thousands of I/O, and which are often networked to other PLC and SCADA systems. They can be designed for many arrangements of digital and analog I/O, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed-up or non-volatile memory. PLCs were first devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OPC HDA
This group of standards, created by the OPC Foundation, provides COM specifications for communicating data from devices and applications that provide historical data, such as databases. The specifications provides for access to raw, interpolated and aggregate data (data with calculations). OPC Historical Data Access, also known as OPC HDA, is used to exchange archived process data. This is in contrast to the OPC Data Access (OPC DA) specification that deals with real-time data. OPC technology is based on client / server architecture. Therefore, an OPC client, such as a trending application or spreadsheet, can retrieve data from an OPC compliant data source, such as a historian, using OPC HDA. Similar to the OPC Data Access specification, OPC Historical Data Access also uses Microsoft's DCOM to transport data. DCOM also provides OPC HDA with full security features such as user authentication and authorization, as well as communication encryption services. OPC HDA Clients and Serv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Levels Of A Distributed Control System
Functional may refer to: * Movements in architecture: ** Functionalism (architecture) ** Form follows function * Functional group, combination of atoms within molecules * Medical conditions without currently visible organic basis: ** Functional symptom ** Functional disorder * Functional classification for roads * Functional organization * Functional training In mathematics * Functional (mathematics), a term applied to certain scalar-valued functions in mathematics and computer science ** Functional analysis ** Linear functional, a type of functional often simply called a functional in the context of functional analysis * Higher-order function, also called a functional, a function that takes other functions as arguments In computer science, software engineering * (C++), a header file in the C++ Standard Library * Functional design, a paradigm used to simplify the design of hardware and software devices * Functional model, a structured representation of functions, activities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Database Management System
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems are equipped with the option of using the SQL (Structured Query Language) for querying and maintaining the database. History The term "relational database" was first defined by E. F. Codd at IBM in 1970. Codd introduced the term in his research paper "A Relational Model of Data for Large Shared Data Banks". In this paper and later papers, he defined what he meant by "relational". One well-known definition of what constitutes a relational database system is composed of Codd's 12 rules. However, no commercial implementations of the relational model conform to all of Codd's rules, so the term has gradually come to describe a broader class of database systems, which at a minimum: # Present the data to the user as relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Database Management System
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems are equipped with the option of using the SQL (Structured Query Language) for querying and maintaining the database. History The term "relational database" was first defined by E. F. Codd at IBM in 1970. Codd introduced the term in his research paper "A Relational Model of Data for Large Shared Data Banks". In this paper and later papers, he defined what he meant by "relational". One well-known definition of what constitutes a relational database system is composed of Codd's 12 rules. However, no commercial implementations of the relational model conform to all of Codd's rules, so the term has gradually come to describe a broader class of database systems, which at a minimum: # Present the data to the user as relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
