The OpenPCS 7 interface is based on various OPC specifications (openness, productivity, collaboration). In addition to Microsoft's DCOM technology (Distributed Component Object Model), it also supports the more sophisticated OPC UA (Unified Architecture) protocol for communication between applications.

Special features of OPC UA:

• Data transfer combined with machine-readable semantic data description
• Platform independence
• Access via firewalls and over the Internet
• Communication reliability
• Security implementation

Access facilities of OPC clients

OPC DA/OPC UA DA (data access server)

For read and write access to process values

As an OPC DA or OPC UA DA server, the OpenPCS 7 server provides other applications with current data from the OS data management. The OPC client can log itself onto ongoing changes and also write values.

OPC HDA (historical data access server)

For read access to archived process values

As an OPC HDA server, the OpenPCS 7 server provides other applications with historical data from the OS archive system. The OPC client, e.g. a reporting tool, can specifically request the required data by defining the start and end of a time interval. Numerous aggregate functions, e.g. variance, mean value or integral, already permit preprocessing by the HDA server and thus contribute toward reduction of the communications load.

OPC A&E (alarm & events server)

For read access to messages, alarms and events

As an OPC A&E server, the OpenPCS 7 server passes on OS messages together with all accompanying process values to the subscribers at the production and corporate management levels. They can of course also be acknowledged there. Filter mechanisms and subscriptions ensure that only selected, modified data are transmitted.

OPC "H" A&E (Historical Alarm & Events Server)

For read access to archived alarms and messages

Thanks to a Siemens extension of the OPC standard interface, the OpenPCS 7 server is able to transmit historic alarms and messages from the archive to subscribers in the production control and corporate control level.

OLE-DB

Simple, standardized direct access to the archive data in the Microsoft SQL server database of the operator system is possible with the OLE-DB. It makes all OS archive data accessible with the accompanying process values, message and user texts.