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OPC Data Access is a group of client–server standards that provides specifications for communicating real-time data from data acquisition devices such as PLCs to display and interface devices like Human–Machine Interfaces (HMI), SCADA systems [2] and also ERP / MES systems. [3] The specifications focus on the continuous communication of data.
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 ...
OPC servers provide a method for different software packages (as long as it is an OPC client) to access data from a process control device, such as a programmable logic controller (PLC) or distributed control system (DCS). Traditionally, any time a package needed access to data from a device, a custom interface or driver had to be written.
The OPC UA architecture is a service-oriented architecture (SOA) and is based on different logical levels. OPC Base Services are abstract method descriptions, which are protocol independent and provide the basis for OPC UA functionality. The transport layer puts these methods into a protocol, which means it serializes/deserializes the data and ...
The OPC Foundation started in 1994, [2] as a task force comprising five industrial automation vendors ( Fisher-Rosemount, Rockwell Automation, Opto 22, Intellution, and Intuitive Technology), [3] with the purpose of creating a basic OLE for Process Control specification. OLE is a technology developed by Microsoft Corporation for the MS Windows ...
Open Database Connectivity. In computing, Open Database Connectivity ( ODBC) is a standard application programming interface (API) for accessing database management systems (DBMS). The designers of ODBC aimed to make it independent of database systems and operating systems. [citation needed] An application written using ODBC can be ported to ...
In computing, Dynamic Data Exchange ( DDE) is a technology for interprocess communication used in early versions of Microsoft Windows and OS/2. DDE allows programs to manipulate objects provided by other programs, and respond to user actions affecting those objects. DDE was partially superseded by Object Linking and Embedding (OLE), and is ...
Operational historian. In manufacturing, an operational historian is a time-series database application that is developed for operational process data. [1] 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. [2]