OPC Foundation
Encyclopedia
The Object Linking and Embedding for Process Control (OPC) Foundation is an industry consortium
that creates and maintains standards for open connectivity of industrial automation devices and systems, such as industrial control systems and process control
generally. The OPC standard
s specify the communication of industrial process data, alarm
s and events, historical data and batch process
data between sensor
s, instrument
s, controllers
, software systems, and notification devices.
The OPC Foundation started in 1994,
as a task force comprising five industrial automation vendors, with the purpose of creating a basic OLE for Process Control
specification. OLE
is a technology developed by Microsoft Corporation for the MS Windows
operating system. The task force released the OPC standard in August 1996. The OPC Foundation was chartered to continue development of interoperability specifications and includes manufacturers and users of devices instruments, controllers, software and enterprise systems.
The OPC Foundation cooperates with other organizations, such as MTConnect
, who share similar missions.
: This group of standards provides specifications for communicating real-time data from data acquisition devices such as PLC's
to display and interface devices like Human-Machine Interface
s (HMI). The specifications focus on the continuous communication of data
OPC Alarm and Events : Standards for communicating alarm and event data on demand, as opposed to the continuous communications in the OPC Data Access group
OPC Batch : Standards to address the needs of batch processes
OPC Data eXchange : This group of standards addresses server to server
communications across industrial networks. The standards also address remote configuration, diagnostics, monitoring and management communications
OPC Historical Data Access
: Standards for communicating stored data
OPC Security : Standards for controlling client access to OPC compliant devices and systems
OPC XML-DA : Builds on the OPC Data Access specifications to communicate data in XML. Incorporates SOAP
and Web services
OPC Complex Data : Standards for specifying the communication of complex data types such as binary data and XML documents
OPC Commands : Standards for communicating control commands to devices and systems
OPC Unified Architecture
: An entirely new set of standards that incorporates all of the functionality of the above standards (and more), but does so using cross platform web services and other modern technology. OPC Unified Architecture
OPC Certification : The OPC Foundation has a well established Certification Process. The OPC Foundation calls this the OPC Enhanced Certification Program.
The OPC Foundation enhanced the range for certification of OPC product to meet the increasing demand for reliable functionality and insured interoperability. The self-certification using the ComplianceTestTool (CTT) and the participation at an Interoperability Workshop (IOP) are now enhanced with a Certification in an independent test facility. According to the test specification here not only the OPC Data Access (DA2/3) interface is tested but also the overall behavior of the product in a real world environment is verified. OPC Certification
Consortium
A consortium is an association of two or more individuals, companies, organizations or governments with the objective of participating in a common activity or pooling their resources for achieving a common goal....
that creates and maintains standards for open connectivity of industrial automation devices and systems, such as industrial control systems and process control
Process control
Process control is a statistics and engineering discipline that deals with architectures, mechanisms and algorithms for maintaining the output of a specific process within a desired range...
generally. The OPC standard
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....
s specify the communication of industrial process data, alarm
Alarm
An alarm device or system of alarm devices gives an audible or visual alarm signal about a problem or condition.Alarm devices include:* burglar alarms, designed to warn of burglaries; this is often a silent alarm: the police or guards are warned without indication to the burglar, which increases...
s and events, historical data and batch process
Batch processing
Batch processing is execution of a series of programs on a computer without manual intervention.Batch jobs are set up so they can be run to completion without manual intervention, so all input data is preselected through scripts or command-line parameters...
data between sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...
s, instrument
Measuring instrument
In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item...
s, controllers
Controller (computing)
In computing and especially in computer hardware, controller is a chip, an expansion card, or a stand-alone device that interfaces with a peripheral device...
, software systems, and notification devices.
The OPC Foundation started in 1994,
as a task force comprising five industrial automation vendors, with the purpose of creating a basic OLE for Process Control
OLE for process control
OLE for Process Control , which stands for Object Linking and Embedding for Process Control, is the original name for a standards specification developed in 1996 by an industrial automation industry task force...
specification. OLE
Object Linking and Embedding
Object Linking and Embedding is a technology developed by Microsoft that allows embedding and linking to documents and other objects. For developers, it brought OLE Control eXtension , a way to develop and use custom user interface elements...
is a technology developed by Microsoft Corporation for the MS Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating system. The task force released the OPC standard in August 1996. The OPC Foundation was chartered to continue development of interoperability specifications and includes manufacturers and users of devices instruments, controllers, software and enterprise systems.
The OPC Foundation cooperates with other organizations, such as MTConnect
MTConnect
MTConnect is a manufacturing industry standard to facilitate the organized retrieval of process information from numerically controlled machine tools. The initiative began as a result of lectures given by David Edstrom of Sun Microsystems and Dr...
, who share similar missions.
OPC Standards and Specification Groups
OPC Data AccessOPC Data Access
The OPC Data Access Specification is the first of a group of specifications known as the OPC Specifications.OPC Data Access is a group of standards that provides specifications for communicating real-time data from data acquisition devices such as PLCs to display and interface devices like...
: This group of standards provides specifications for communicating real-time data from data acquisition devices such as PLC's
Programmable logic controller
A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
to display and interface devices like Human-Machine Interface
Human-machine interface
Human-machine interface is the part of the machine that handles the Human-machine interaction- Overview :In complex systems, the human-machine interface is typically computerized. The term Human-computer interface refers to this kind of systems....
s (HMI). The specifications focus on the continuous communication of data
OPC Alarm and Events : Standards for communicating alarm and event data on demand, as opposed to the continuous communications in the OPC Data Access group
OPC Batch : Standards to address the needs of batch processes
Batch processing
Batch processing is execution of a series of programs on a computer without manual intervention.Batch jobs are set up so they can be run to completion without manual intervention, so all input data is preselected through scripts or command-line parameters...
OPC Data eXchange : This group of standards addresses server to server
Inter-server
In computer network protocol design, inter-server communication is an extension of the client–server model in which data are exchanged directly between servers...
communications across industrial networks. The standards also address remote configuration, diagnostics, monitoring and management communications
OPC Historical Data Access
OPC Historical Data Access
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 .OPC Historical Data Access, also...
: Standards for communicating stored data
OPC Security : Standards for controlling client access to OPC compliant devices and systems
OPC XML-DA : Builds on the OPC Data Access specifications to communicate data in XML. Incorporates SOAP
SOAP
SOAP, originally defined as Simple Object Access Protocol, is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks...
and Web services
OPC Complex Data : Standards for specifying the communication of complex data types such as binary data and XML documents
OPC Commands : Standards for communicating control commands to devices and systems
OPC Unified Architecture
OPC Unified Architecture
OPC Unified Architecture is the most recent OLE for process control specification from the OPC Foundation and differs significantly from its predecessors. The first version of Unified Architecture was released in 2006, after 3 years of specification work and another year of prototyping...
: An entirely new set of standards that incorporates all of the functionality of the above standards (and more), but does so using cross platform web services and other modern technology. OPC Unified Architecture
OPC Certification : The OPC Foundation has a well established Certification Process. The OPC Foundation calls this the OPC Enhanced Certification Program.
The OPC Foundation enhanced the range for certification of OPC product to meet the increasing demand for reliable functionality and insured interoperability. The self-certification using the ComplianceTestTool (CTT) and the participation at an Interoperability Workshop (IOP) are now enhanced with a Certification in an independent test facility. According to the test specification here not only the OPC Data Access (DA2/3) interface is tested but also the overall behavior of the product in a real world environment is verified. OPC Certification