Result
Understand the default bar and how it will be used when creating measures from the tags in your data source’s Namespace.
Tutorial steps
- Locate the default Bar - in the Flow Configuration tool.
- Default Time Base – set this to Tag. By doing this you are telling Flow that you want to create a tag which retrieves all the data points from a data source
- Default Format – set this to 0.0 (to give us 1 decimal place).
- Default Unit of Measure (UOM) – ignore this for now because the Historian supports engineering units.
- Default Backfill Date – set this to the beginning of last month (notice the hour starts at 07:00 based on our calendar definition).
Browse through the Historian’s Namespace until you find tags relating to the Juice Factory’s Boiler. Hover over these tags to see a brief description of what they represent. Using the description and the engineering units, you should get a good idea of what these tags are.
Let’s focus on the Temperature tag, 010-TT-001.PV, measured in ˚C. The value of this tag is most likely being stored in the Historian at a high resolution, possibly every second.
You can create a Flow "Tag" which will fetch this high-resolution data from the Historian. You can then report on the average temperature every hour by creating an "Hourly" measure which aggregates the Tag.
You want to report the average temperature to 1 decimal place (i.e. 98.2 ˚C). You also know that your Historian has a few months of data already stored, so let’s go back and retrieve the average temperature for every hour as far back as we can.
Given that you know a few of the settings required to report on the Boiler Temperature, it is useful to pre-select the Measure defaults as described in the tutorial steps above.