OPC stands for 'OLE for Process Control' and defines the data exchange within a Windows® environment. This can be a user program such as a process visualisation or a SoftPLC but it can also be a fieldbus interface which provides process data by means of a standardised OPC interface.
The data transfer is carried out on the Client/Server principle. Here, the fieldbus interface must prepare the OPC Server function, whilst the application calls up the data as Client. Our OPC Server can administer up to four PC cards, of different types as well as also of different fieldbus systems. It provides the application with the useful data in the required data format without the user having to bother about the details as to how it accesses the data. The information it needs is retrieved from the configuration data base of the System Configurator.
During the configuration of the fieldbus system with the aid of the SyCon® System Configuration, the user defines the process variables and determines so-called 'tag names'. The OPC Client calls up the process variables by using these names of the variables.
In addition the Client can call up, for example, of a visualisation via the OPC browse function all the variable definitions from the SyCon®. This saves a duplicated entry of the variable names and the tedious balancing of the process variables between application and fieldbus system.