An ideal team: OPCom and SPSPlusWIN

SAE-STAHL has introduced the OPCom software suite as a complement to its established project planning and engineering software, SPSPlusWIN. OPCom is a communication toolkit for standard PCs built on the generic OPC (OLE for process control) software interface, which is itself based on Microsoft's COM and DCOM technology. It acts as a broker between devices in the field and higher-level process controls, database applications and visualisations.

The OPCom suite makes the whole range of SAE-STAHL's operating and monitoring systems ready for OPC, opening up an abundance of possible applications. Control terminals in the field, whether for inventory management, for production data acquisition or for operation on location – even in the Ex-area –, can interact directly with the central process controls or with databases.

Typical applications are found e.g. in controlled access areas in refineries, where user ID clearances are tracked by a SCADA system (Supervisory Control and Data Acquisition). An OPC server allows access from anywhere in the corporate network to all data collected via keypads, touch screens, barcode scanners, smart card readers etc., from the moment they are registered at the terminal. Since SCADA systems are usually designed to interface with Modbus servers, OPCom provides full Modbus integration.

The EP-COM-Server employs event-triggered drivers with an OPC server interface and is optimised for all Exicom and ProVicom terminals. Its interaction with screen templates of SPSPlusWIN-configured visualisation and control applications follows a simple procedure: Whenever user input is completed and turned over to the system for processing by pressing the corresponding key, form parameters are aggregated in a data structure and forwarded by the EP-COM-Server. Incoming data structures can be processed e.g. by VBA objects (Visual Basic for Applications). OPCom also includes an OPC-DB-Server to facilitate queries to database systems, such as Oracle and MySQL.