OPC Dictionary & Glossary of Terms


 

WordDefinition
AGAThe American Gas Association (AGA) represents 192 local energy utility companies that deliver natural gas to more than 53 million homes, businesses and industries throughout the United States. Visit the AGA website at www.aga.org.
APIApplication Programming Interface (API) is a set of software functions used by an application program as a means for providing access to a specific application or operating system's capabilities.
BACnetBACnet is a Data Communications Protocol for Building Automation and Control Networks It is an ASHRAE ANSI and ISO standard protocol.
BrowseAn OPC interface that enables an OPC client application to view all of the available tag items of an OPC server.
CDPDCellular Digital Packet Data (CDPD) is a technology installed on many analog cellular towers for transmitting and receiving data over cellular networks. Technology that allows data files to be broken into a number of "packets" and sent along idle channels of existing cellular voice networks.
Central Processing UnitCentral Processing Unit (CPU) is the main processing chip of a computer. the part of the computer or computer system which performs core processing functions.
ClientA software program that is used to contact and obtain data from a Server software program either on the same computer or on another computer A client makes a request and the server fulfills the request An example of a client would be an email program connecting to a mail server or an Internet browser client connecting to a web server In the case of OPC an HMI would be a client application that connects to an OPC server Also related is Server
COMComponent Object Model (COM) is a Microsoft concept used to communicate between components on the same computer. Components from different machines can be combined using DCOM (See DCOM).
Component Object ModelComponent Object Model (COM) is a Microsoft concept used to communicate between components on the same computer. Components from different machines can be combined using DCOM (See DCOM).
COTSCommercial off-the-shelf (COTS) is commercially available products that are purchased and integrated with little configuration. Typically COTS reduces integration cost and time.
CPUCentral Processing Unit (CPU) is the main processing chip of a computer. the part of the computer or computer system which performs core processing functions.
CRCCyclical Redundancy Check (CRC) is a procedure used to check for errors in data transmission.
Cyclical Redundancy CheckCyclical Redundancy Check (CRC) is a procedure used to check for errors in data transmission.
DAQAlso known as Data Acquisition, DAQ is the collection and measurement of signals from sensors, transducers, and probes for processing.
DASAlso known as Data Acquisition System, DAQ is a system of one or more sensors, devices and communication links used to scan or collect and forward data to a central location for further processing, display, or archiving.
Data Acquisition SystemAlso known as DAQ, Data Acquisition System is a system of one or more sensors, devices and communication links used to scan or collect and forward data to a central location for further processing, display, or archiving.
DatabaseA database is an organized collection of information in digital or electronic format.
DCOMDistributed Component Object Model (DCOM) is a set of Microsoft concepts and program interfaces in which client program objects can request services from server program objects on other computers in a network. DCOM is based on the Component Object Model (COM), which provides a set of interfaces allowing clients and servers to communicate within the same computer.
DCSDistributed Control System (DCS) is a big Programmable Logic Controller (PLC) that is typically networked to other controllers, PLCs or field devices. It typically has a workstation to interface with the controller and can be very expensive due to built-in security and fail-over features.
DDEDynamic Data Exchange (DDE) is a form of InterProcess Communication (IPC) in the Microsoft Windows operating environment. When two or more applications that support DDE are running simultaneously, they can exchange information, data and commands. DDE has been enhanced with Object Linking and Embedding (OLE) technology.
Dead-BandDead-Band is the range through which the input may be varied without initiating a response.
depData Execution Prevention
Distributed Component Object ModelDistributed Component Object Model (DCOM) is a set of Microsoft concepts and program interfaces in which client program objects can request services from server program objects on other computers in a network. DCOM is based on the Component Object Model (COM), which provides a set of interfaces allowing clients and servers to communicate within the same computer.
Distributed Control SystemDistributed Control System (DCS) is a big Programmable Logic Controller (PLC) that is typically networked to other controllers, PLCs or field devices. It typically has a workstation to interface with the controller and can be very expensive due to built-in security and fail-over features.
DNP3DNP is Distributed Network Protocol a communications protocol used for SCADA telemetry systems
Dynamic Data ExchangeDynamic Data Exchange (DDE) is a form of InterProcess Communication (IPC) in the Microsoft Windows operating environment. When two or more applications that support DDE are running simultaneously, they can exchange information, data and commands. DDE has been enhanced with Object Linking and Embedding (OLE) technology.
Enterprise Resource PlanningEnterprise Resource Planning (ERP) is an information system that integrates all manufacturing and related applications for an entire enterprise.
ERPEnterprise Resource Planning (ERP) is an information system that integrates all manufacturing and related applications for an entire enterprise.
ESDEmergency Shutdown System
Extensible Markup LanguageExtensible Markup Language (XML) is a flexible way to create standard information formats and share both the format and the data on the World Wide Web and with disparate operating systems.
General Packet Radio ServiceGeneral Packet Radio Service (GPRS) is a wireless data transmission service based on packet transmission.
GPIGeneral Purpose Interface
GPRSGeneral Packet Radio Service (GPRS) is a wireless data transmission service based on packet transmission.
Graphical User InterfaceGraphical User Interface (GUI) enables a user to interact with a software application through graphics instead of text.
GUIGraphical User Interface (GUI) enables a user to interact with a software application through graphics instead of text.
HistorianA historian is a type of database designed to store process data. Due to the enormous amount of process data some plants produce, some historians compress data using algorithms. Others historians are designed to act as a "rolling buffer" and are able to store high frequency data. See desktop historian.
HMIHuman Machine Interface (HMI) is a software application (typically a Graphical User Interface or GUI)that present information to the operator about the state of a process, and to accept and implement the operators control instructions. It may also interpret the plant information and guide the interaction of the operator with the system. Also known as Man Machine Interface (MMI).
HTTPHyperText Transfer Protocol (HTTP) is the protocol for moving hypertext files across the Internet. Requires a HTTP client program on one end, and an HTTP server program on the other end.
Human Machine InterfaceHuman Machine Interface (HMI) is a software application (typically a Graphical User Interface or GUI)that present information to the operator about the state of a process, and to accept and implement the operators control instructions. It may also interpret the plant information and guide the interaction of the operator with the system. Also known as Man Machine Interface (MMI).
HyperText Transfer ProtocolHyperText Transfer Protocol (HTTP) is the protocol for moving hypertext files across the Internet. Requires a HTTP client program on one end, and an HTTP server program on the other end.
in procIn process In context of OPC in proc OPC Servers are typically dlls that are launched by and controlled by OPC Clients Advantages include performance and ease of DCOM configuration
Infrared Data AssociationInfrared Data Association (IrDA) is agreed upon standard that enables data to be transferred between devices using infrared light instead of cables.
Inter-Process Communication (IPC)Inter-Process Communication (IPC) transfers information between processes or between the kernel and a process.
Internet ProtocolInternet Protocol (IP) is the basic network transmission protocol of the Internet.
IPInternet Protocol (IP) is the basic network transmission protocol of the Internet.
IPCInter-Process Communication (IPC) transfers information between processes or between the kernel and a process.
IrDAInfrared Data Association (IrDA) is agreed upon standard that enables data to be transferred between devices using infrared light instead of cables.
LANLocal Area Network (LAN) is a computer network typically limited to a small geographic area, usually the same building/plant or floor of a building/plant.
Local Area NetworkLocal Area Network (LAN) is a computer network typically limited to a small geographic area, usually the same building/plant or floor of a building/plant.
LonWorksLonWorks is a networking platform specifically created to address the unique performance reliability installation and maintenance needs of control applications The platform is built on a low bandwidth protocol created by Echelon Corporation for networking devices over media such as twisted pair powerlines fiber optics and RF It is popular for the automation of various functions within buildings such as lighting and HVAC see Intelligent building
Man Machine InterfaceMan Machine Interface (MMI) is a software application (typically a Graphical User Interface or GUI)that present information to the operator about the state of a process, and to accept and implement the operators control instructions. It may also interpret the plant information and guide the interaction of the operator with the system. Also known as Human Machine Interface (HMI).
MatrikonOPCMatrikonOPC is the world's largest developer and supplier of OPC drivers, clients, applications, tools and utilities. In addition we provide services including training and installation as well as a full-time support department.
MMIMan Machine Interface (MMI) is a software application (typically a Graphical User Interface or GUI)that present information to the operator about the state of a process, and to accept and implement the operators control instructions. It may also interpret the plant information and guide the interaction of the operator with the system. Also known as Human Machine Interface (HMI).
ModbusModbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers PLCs It has become a de facto standard communications protocol in industry and is now the most commonly available means of connecting industrial electronic devices.
ODBCOpen DataBase Connectivity (ODBC) is a Microsoft standard for accessing different database systems from Windows such as SQL, Access or Oracle.
ODMOPC Data Manager (ODM) is an OPC utility developed by MatrikonOPC used to share process data between two or more control systems. See MatrikonOPC Data Manager.
OLEObject Linking and Embedding
OLE for Process ControlOLE for Process Control (OPC) is a set of standard interfaces based upon Microsoft's OLE/COM technology. The application of the OPC standard interface makes possible interoperability between automation/control applications, field systems/devices etc.
OPCOLE for Process Control (OPC) is a set of standard interfaces based upon Microsoft's OLE/COM technology. The application of the OPC standard interface makes possible interoperability between automation/control applications, field systems/devices etc.
OPC A&EOPC Alarms and Events (OPC A&E) is used to exchange process alarms and events. OPC A&E can be used by operations to notify them of alarms and obtain a sequence of events.
OPC Alarms & EventsOPC Alarms and Events (OPC A&E) is used to exchange process alarms and events. OPC A&E can be used by operations to notify them of alarms and obtain a sequence of events.
OPC BatchOPC Batch is a specification published by the OPC Foundation. This specification carries the OPC philosophy to the specialized needs of batch processes. It provides interfaces for the exchange of equipment capabilities (corresponding to the S88.01 Physical Model) and current operating conditions.
OPC CommandsA specification published and maintained by the OPC Foundation. OPC Commands defines a new set of interfaces that allow OPC clients and servers to identify, send and monitor control commands which execute on a device.
OPC Complex DataOPC Complex Data is a standard published by the OPC Foundation. It is a companion specification to OPC Data Access and OPC XML-DA that allows servers to expose and describe more complicated data types such as binary structures and XML documents.
OPC ComplianceOPC Compliance LogoThe OPC Foundation offers certification to ensure that OPC servers meet the defined specification. The OPC Foundation has produced automated tools used for vendors to test their OPC products. Those products that past the test can be classified as OPC Certified and display the OPC Compliance logo.
OPC CompliantOPC Compliance LogoThe OPC Foundation offers certification to ensure that OPC servers meet the defined specification. The OPC Foundation has produced automated tools used for vendors to test their OPC products. Those products that past the test can be classified as OPC Certified and display the OPC Compliance logo.
OPC DAOPC Data Access (OPC DA) provides access to real time process data. Using OPC DA, one can ask the OPC server for the most recent value of flows, pressures, levels, temperatures, densities, and more. For historical data see OPC Historical Data Access (OPC HDA).
OPC Data AccessOPC Data Access (OPC DA) provides access to real time process data. Using OPC DA, one can ask the OPC server for the most recent value of flows, pressures, levels, temperatures, densities, and more. For historical data see OPC Historical Data Access (OPC HDA).
OPC Data eXchange (OPC DX)OPC Data eXchange (OPC DX) is a specification defines how OPC servers exhange data with other OPC servers.
OPC Data ManagerOPC Data Manager (ODM) is an OPC utility developed by MatrikonOPC used to share process data between two or more control systems. See MatrikonOPC Data Manager.
OPC DriverAn OPC Driver is a software application that acts as an API (Application Programming Interface) or protocol converter. An OPC Driver will connect to a device such as a PLC, DCS, RTU, etc or a data source such as a database, HMI, etc and translate the data into a standard-based OPC format. OPC compliant applications such as an HMI, historian, spreadsheet, trending application, etc can connect to the OPC Driver and use it to read and write device data. An OPC Driver is analogous to the roll a printer driver plays to enable a computer to communicate with an ink jet printer. An OPC Driver is based on a Server/Client architecture.
OPC DXOPC Data eXchange (OPC DX) is a specification defines how OPC servers exhange data with other OPC servers.
OPC FoundationThe OPC Foundation is made up of over 350 companies, organizations and individuals. They are responsible for developing and maintaining the OPC Specifications and ensuring product interoperability and compliance. Visit the OPC Foundation's website at www.opcfoundation.org.
OPC HDAOPC Historical Data Access (OPC HDA) is used to retrieve and analyze historical process data, which is typically stored in a Process Data Archiver, a database, or an RTU. For real-time data, see OPC Data Access (OPC DA).
OPC Historical Data AccessOPC Historical Data Access (OPC HDA) is used to retrieve and analyze historical process data, which is typically stored in a Process Data Archiver, a database, or an RTU. For real-time data, see OPC Data Access (OPC DA).
OPC Interoperability WorkshopsThe OPC Foundation arranges workshops hosted by member companies, where participants can test their latest OPC devices. This helps ensure that multi-vendor products interoperate with one another. Successfully tested client/server pairs are published on the OPC Foundation’s website.
OPC Redundancy BrokerOPC Redundancy Broker (ORB) is a software utility that provides driver (server) level redundancy to any control system. Typically used when loss of data is unacceptable. See MatrikonOPC Redundancy Broker.
OPC SecurityOPC Security is a standard published by the OPC Foundation. OPC Security specifies how to control client access to servers in order to protect sensitive information and to guard against unauthorized modification of process parameters.
OPC ServerAn OPC Server is a software application that acts as an API Application Programming Interface or protocol converter An OPC Server will connect to a device such as a PLC DCS RTU etc or a data source such as a database HMI etc and translate the data into a standard based OPC format OPC compliant applications such as an HMI historian spreadsheet trending application etc can connect to the OPC Server and use it to read and write device data An OPC Server is analogous to the roll a printer driver plays to enable a computer to communicate with an ink jet printer An OPC Server is based on a ServerClient architecture
OPC Tunnelling TechnologyOPC technology that transfers process data between networked computers using TCP/IP instead of DCOM. See Matrikon OPC Tunneller.
OPC UAOPC Unified Architecture (OPC UA) will replace, modernize and enhance all the functionality of the existing OPC defined interfaces. OPC UA is described in a layered set of specifications broken into Parts. It is purposely described in abstract terms and in later parts married to existing technology on which software can be built. This layering is on purpose and helps isolate changes in OPC UA from changes in the technology used to implement it. Click here for more information.
OPC Unified ArchitectureOPC Unified Architecture (OPC UA) will replace, modernize and enhance all the functionality of the existing OPC defined interfaces. OPC UA is described in a layered set of specifications broken into Parts. It is purposely described in abstract terms and in later parts married to existing technology on which software can be built. This layering is on purpose and helps isolate changes in OPC UA from changes in the technology used to implement it. Click here for more information.
OPC XMLOPC Extensible Markup Language (OPC XML) encapsulates process control data making it available across all operating systems.
OPC2XLHas been deprecated See Matrikon Analytics Excel Reporter
Open DataBase ConnectivityOpen DataBase Connectivity (ODBC) is a Microsoft standard for accessing different database systems from Windows such as SQL, Access or Oracle.
Open Virtual Memory SystemOpen Virtual Memory System (OpenVMS) is the operating system on a VAX node (also related is Virtual Memory System - VMS).
OpenVMSOpen Virtual Memory System (OpenVMS) is the operating system on a VAX node (also related is Virtual Memory System - VMS).
Operating SystemOperating System (OS) is a software program, which manages the basic operations of a computer system. These operations include memory appointment, the order and method of handling tasks, flow of information into and out the main processor and to peripherals, etc.
ORBOPC Redundancy Broker (ORB) is a software utility that provides driver (server) level redundancy to any control system. Typically used when loss of data is unacceptable. See MatrikonOPC Redundancy Broker.
OSOperating System (OS) is a software program, which manages the basic operations of a computer system. These operations include memory appointment, the order and method of handling tasks, flow of information into and out the main processor and to peripherals, etc.
out of procOut of process In context of OPC most OPC Servers are out of process exes They are processes that are separate from the OPC Client processes that access them Advantages to out of proc include ability to access remotely and being a better model for sharing the same data with multiple clients
PDUProtocol Design Utility
PLCProgrammable Logic Controller (PLC) is an industrial device that provides an interface for input sensors and output actuators. PLCs can be programmed using relay ladder logic to control the outputs based on input conditions and / or algorithms contained in the memory of the PLC.
PollingPolling is the process in which a number of peripheral devices, remote stations, or nodes within a plant-based or SCADA network are accessed by a client application via a server to read and write data.
Process HistorianA process historian is a type of database designed to store process data. Due to the enormous amount of process data some plants produce, some process historians compress data using algorithms. Other process historians are designed to act as a "rolling buffer" and are able to store high frequency data. See desktop historian
ProgIDDefinition ProgramID a human readable alias for your OPC Server Example ProgID MatrikonOPCSimulation
Programmable Logic ControllerProgrammable Logic Controller (PLC) is an industrial device that provides an interface for input sensors and output actuators. PLCs can be programmed using relay ladder logic to control the outputs based on input conditions and / or algorithms contained in the memory of the PLC.
PTUProtocol Test Utility
Radio Frequency IdentificationAlso known as RFID, it is a technology that has existed for decades. At a simple level, it is a technology that involves tags that emit radio signals and devices called readers that pick up the signal.
Relational DatabaseA relational database is a collection of data items organized in a set of pre-defined tables from which data can be accessed without reorganizing the tables.
Remote Terminal UnitRemote Terminal Unit (RTU) is an industrial data collection device typically located at a remote location and communicates data to a host system by using telemetry (such as radio, dial-up telephone, or leased lines).
RFIDRFID stands for Radio Frequency Identification. It is a technology that has existed for decades. At a simple level, it is a technology that involves tags that emit radio signals and devices called readers that pick up the signal.
RTURemote Terminal Unit (RTU) is an industrial data collection device typically located at a remote location and communicates data to a host system by using telemetry (such as radio, dial-up telephone, or leased lines).
SBCSingle Board Computer
SCADASupervisory Control and Data Acquisition (SCADA) is a common process control application that collects data from sensors on the shop floor or in remote locations and sends them to a central computer for management and control.
ServerA software application designed to bridge the communication between a device, controller or data source with a client application. Servers can only respond to requests made by a client. An example would be an HMI, an client, asking the OPC server for the latest value of a particular process value. Also related is Client.
Set-PointThe set-point is defined as the value where you would like a process variable to be. For example, the temperature of a boiler may have a set-point of 100 degrees or a flow valve has a set-point of 50 gallons per minute.
SNMPSimple Network Management Protocol The network management protocol used almost exclusively in TCPIP networks SNMP provides a means to monitor and control network devices and to manage configurations statistics collection performance and security.
SQLStructured Query Language (SQL) is a standard computer language for communicating with a relational database.
Structured Query LanguageStructured Query Language (SQL) is a standard computer language for communicating with a relational database.
Supervisory Control and Data AcquisitionSupervisory Control and Data Acquisition (SCADA) is a common process control application that collects data from sensors on the shop floor or in remote locations and sends them to a central computer for management and control.
TCP/IPTransmission Control Protocol/Internet Protocol (TCP/IP is the basic communication language or protocol of the Internet.
Transmission Control Protocol/Internet ProtocolTransmission Control Protocol/Internet Protocol (TCP/IP is the basic communication language or protocol of the Internet.
UAUA Unified Architecture is the most recent OPC specification from the OPC Foundation and differs significantly from previous specifications UA combines the functionality of the existing OPC interfaces with new technologies such as XML and Web Services to deliver higher level MES and ERP support
UCS MatrikonOPC Universal Connectivity Server UCS is a single OPC Server that enables multiple communications protocols to communicate with data sources in a realtime and secure matter Universal Connectivity Server
UDPUser Datagram Protocol (UDP) transports data as a connectionless protocol, using packet switching.
User Datagram ProtocolUser Datagram Protocol (UDP) transports data as a connectionless protocol, using packet switching.
VBVisual Basic (VB) is a popular Microsoft programming language used by software vendors and developers to build graphical client application interfaces.
Virtual Memory SystemVirtual Memory System (VMS) is the operating system on a VAX node (also related is Open Virtual Memory System - OpenVMS).
Visual Basic Visual Basic (VB) is a popular Microsoft programming language used by software vendors and developers to build graphical client application interfaces.
VMSVirtual Memory System (VMS) is the operating system on a VAX node (also related is Open Virtual Memory System - OpenVMS).
WANWide Area Network (WAN) is a computer network covering a large geographical area, usually consisting of two or more LANs.
Wide Area NetworkWide Area Network (WAN) is a computer network covering a large geographical area, usually consisting of two or more LANs.
XMLExtensible Markup Language (XML) is a flexible way to create standard information formats and share both the format and the data on the World Wide Web and with disparate operating systems.