Handle multiple engines

It may be efficient in a system to distribute the load of Automation Object instances into multiple engines. It is a particular advantage when running the application in a multi-processor PC, as each engine running in its own single thread, will be distributed by the Operating System throughout the processors.

In Industrial Application Server 2.0, a platform can host a maximum of 20 engines. The platform counts as one engine, leaving 19 available slots. However, it is not recommended to use more than 16 engines on a single platform. Using more than 16 engines on a platform may deteriorate system performance.

To determine whether to place multiple Engines on a platform, analyze the Scheduler.ExecutionTimeAvg in the Object Viewer and strive to not to exceed over 30% - 40% of the scan cycle execute time. Also, if the speed you require cannot be accommodated with one engine, you may need to split engines.

You may need multiple engines (1) when there are differing scan rates or scan overruns, (2) when there is high execution time and/or (3) when you need to bring data in faster. When you have sets of objects that do not require fast execution, you can group them on one engine. In a system in which you can group application objects based on scan rates, use a platform for each object group.

Important! Be sure to monitor CPU usage when adding engines. Also, remember that with multiple engines you are moving Areas. If you have only one Area, you must create sub-areas.