An Accumulated virtual stream is a stream that keeps a running total of its parent stream’s output values, starting from a configurable Start-Datetime.
An Accumulated virtual stream is a stream that keeps a running total of its parent stream’s output values, starting from a configurable Start-Datetime. You can also set a Starting Value that will be added to the total.
The final value of the Accumulated stream at any given time is the total of all the raw values up to this time, starting from the Start Datetime, with the addition of the Starting Value.
This type of stream is useful in various scenarios. Here are some typical use cases:
- How much water is used every week: In this case, the parent stream measures how many times an hour a liter of water flows through a pipe. If you want to know how much water flowed through in a week, you can set the Starting Value of the Accumulated virtual stream to zero just after midnight Sunday night, and then check the total seven days later, just before midnight Sunday night.
- How many times the runoff pump was activated during a rain event: In this case, the parent stream measures water level and sends a pulse, thus activating a pump, whenever water level exceeds a threshold. If you want to know how many times the pump was activated during a rain event, set the Starting Value of the Accumulated virtual stream to zero for the datetime when the rain event started, and check the total at the datetime when the rain event ended.
- How much rain fell during a rain event or to date: In this case, the parent steam measures every 10 minutes how much rain fell in the past 10 minutes. If you want to know how much rain fell during the entire rain event, set the Starting Value of the Accumulated virtual stream to zero for the datetime when the rain event started. Or, if you know that rainfall this year prior to the rain event was 70 cm, you can set the virtual stream's Starting Value to 70 in order to learn this year's rainfall to date.
To configure an Accumulated virtual stream:
- In the left pane, select the device whose stream you want to configure.
- In the Sites Tree pane, select the Accumulated Virtual stream.
- In the right pane, click Configuration & Threshold. In the Convert to Engineering Units area, click the pencil icon
. The Add New Starting Value window opens. - In the Starting Value field, enter a number.
- In the Date field, click the calendar icon to select a starting date. Select a time in the drop-down list.
- Click Submit.