Hi adand ,

The Rollup function is specifically an asset-based calculation. If you have not created a virtual view with assets, then this function is of no use. Also, it can only run on a Periodic frequency, not on Value Change.

If you have a virtual view that has assets, you will want to pick that view using the Asset Path. Then you will want to select a parent asset type from the Asset Type drop-down. In my screenshot, the PumpingStation is a parent asset of a Pump asset.

The first parameter in the function is the source path which is the 'Asset Path + %Asset%'. We use %Asset% as a wildcard as each asset has a unique path. The second parameter is one of the Rollup operations. In my example, I am using Average. The third parameter is the child asset type. In this example, the Pump asset is a child asset of the PumpingStation. The fourth parameter is a tag of the child asset. In this case, each Pump has a Flow tag.

So every hour this calculation will average the Flow tag of each Pump and roll that value up to its parent PumpingStation.

The output must contain the wildcard, %Asset%, as is the case for all asset-based calculations.

Each PumpingStation will now have an hourly [PumpFlowAvg] tag.