Product Features
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Analytics
Key Performance Indicators
Change of Value
3min
The Change of Value KPI displays the complete message payload when the current value differs from the previous value. If there is no substantial change, no output is displayed.
- Show the entire message payload when the current value is different than the previous value.
- A simple use-case of this KPI is: you want to see a message ONLY if there is a significant change from the previous value, otherwise if things are normal, no output is expected.
- By entering a delta, you can ignore some precision errors.
- If you enter delta as 0.0, even the smallest change will be detected by this KPI, or you can enter a delta of 0.1 (for example) if you want to allow ignore a change of +/- 0.1 from your previous value.
- Map Field Name asks you what is the field you want to observe for COV. This can be "value" or "asset_online" etc. depending entirely on what is the input message you are sending to this KPI.
- The timer interval parameter is useful if the connected input tag is currently not polling, but you still want this KPI to publish a value every few seconds, defined by the aforementioned timer.
- If you know your input is going to publish at the expected interval, it is better to disable this timer by entering 0 in this field.
- Expected Output: No output if the current value is the same as the previous value (+ or - delta), but outputs the entire input message if there is a change.
Parameters | Details |
|---|---|
Map Field Name | This parameter specifies the field to observe for Change of Value (COV), such as "value". |
Delta of Tolerance | This parameter allows you to specify the amount of difference between the current and previous values to ignore, thus helping to disregard some rounding errors. |
Timer Interval | Timer in milliseconds. If no event, use this timer to keep displaying the output continually. Enter zero to disable. |
Change of Value Parameter
Note: When creating an analytics flow with Change of Value KPI, refer the Use the Change of Value KPI guide for more details.