In an effort to improve interoperability between applications, Microsoft masterminded a number of client-server communication protocols in the 1980s-1990s for its range of Windows operating systems using standardized data exchange interfaces.
DDE (Dynamic Data Exchange) was the first protocol to be introduced with the release of Windows 2.0 and OS/2 in 1987, followed by the first version of OLE (Object Linking and Embedding) in 1990. Several variations of OLE rolled off Microsoft's development line, culminating in OLE for Process Control (OPC) in 1995. This version was designed to improve interoperability between manufacturing systems and has since become one of the gold standard protocols in industry for exchanging data between applications.
These protocols have enabled automated systems manufacturers and monitoring software vendors to open up their solutions to third-party applications by incorporating OPC or DDE interfaces to support data exchanges.
To build a bridge between ALERT and other business applications, we have incorporated OPC client and server interfaces to satisfy a wide range of needs.
The client interface can be used to acquire data, events and alarms from third-party applications with an OPC server interface. Users can also automatically drill down into the data requiring close observation.
The server interface shows the state of the software's different variables in real time (alarms, system information, etc.), thereby allowing third-party applications and also ALERT to monitor the state of the entire system.
Several OPC standards are available, and ALERT includes the following:
|Type of OPC link||Operating mode|
|DA (Data Access)||Client/Server|
|AE (Alarm and Events)||Client|
|UA (Unified Architecture)||Client|
The DDE client interface incorporated into ALERT as standard automatically acquires data from any DDE server application.
The software also features a DDE server interface for delivering information in real time about the configuration of its state and processing standard CMD commands.