Scenario 3: Track liquid and gas use with custody meters

You can use the Counter retrieval feature to keep track of how much liquid or gas a process uses. For example, you could answer questions like:

• How much syrup was dispensed from Tank 3?

• How much propane have we used so far this month?

Using Counter Retrieval with Floating Point Counters

Counter retrieval also works with floating point counters, which is useful for flow meter data. Similar to the carton counter, some flow meters report accumulated flow and "roll over" after a certain amount of flow accumulates. For both examples, the need is to convert the accumulating measure to a "delta change" value over a given period. (For an example of totalizing a flow rate, see Scenario 5.)

Example: Tracking Liquid or Gas Volumes with Counter Retrieval

SELECT DateTime, TagName, Value, Quality, QualityDetail AS QD

FROM History

WHERE TagName like 'ReceivedVolume.Counter'

AND DateTime >= '2015-09-01 13:00'

AND DateTime < '2015-09-03 18:00'

AND wwResolution=3600000

AND wwRetrievalMode='counter'

AND wwQualityRule='optimistic'

AND wwTimeStampRule='start'

The results are: