The Operator MES system relies on data gathered from the shop floor. To ensure the reliability of data, data must be gathered automatically and continuously. That is why the Operator team is constantly working on improving the performance and reliability of our machine integration solutions. Our newest innovation, including many improvements and new features, is the Operator Datalogger (ODL).
The Operator Datalogger is a Windows service which establishes a reliable connection between the OPC Server and the Operator Database. As the ODL runs independently of the Operator MES, it can be installed on the OPC server, while the Operator MES runs on another computer within the same network. This provides many advantages, including the prevention of DCOM configuration issues that can arise when connecting to an OPC server remotely.
The ODL runs in the background on the computer hosting the OPC server. Its purpose is to create OPC subscriptions, which are configured in the Operator Database. Based on these subscriptions, the service will conduct reads and writes between the OPC Server and the Operator Database.
The ODL is designed to take advantage of multithreaded design. This means that subscriptions are grouped, and each group is handled by a separate thread. Thus, the overhead is minimized in many cases, e.g., when multiple subscriptions are handled at the same time. The operating system also ensures an even distribution of system resources to the threads.
The ODL can run two subscription types – synchronous and asynchronous (SYNC / ASYNC). Synchronous reads are reads done with a configured frequency independent of actual values. Asynchronous reads are event-driven, meaning that the subscription generates an event each time the subscribed OPC item’s value changes. The ODL also supports the writing of data directly to the OPC server.
This approach allows the ODL to handle large amounts of data changes with minimal performance impact.