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Documentation Index

Fetch the complete documentation index at: https://docs.siftstack.com/llms.txt

Use this file to discover all available pages before exploring further.

After completing this topic, you can narrow down the root cause of an anomaly by isolating the affected time range and comparing related signals.

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Before you begin

  • You have a Run with an identified anomaly open in Explore with the affected Channel plotted.

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How anomaly investigation works

When a signal shows unexpected behavior, you can zoom into the affected time range and plot related Channels side by side to determine whether the anomaly is isolated to a single signal or correlated across multiple signals. Comparing related Channels helps narrow down the root cause, such as a sensor failure, an environmental event, or a system-level issue.

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Investigate an anomaly

  1. In the toolbar, select a range control to zoom into the time range where the anomaly occurs.
    • Range controls are available in Timeseries, FFT, and Scatter Plot Panels.
  2. Add related Channels to the same Panel or split the Panel by right-clicking its tab and selecting a split direction to compare signals in an adjacent Panel.
  3. Optional: Create a Calculated Channel to derive a signal that highlights the anomaly, such as a difference or ratio between two Channels:
    1. Click the Calculated Channels tab.
    2. Click Create new Calculated Channel.
    3. Select the Asset to attribute the Calculated Channel.
    4. In the Calculated Channel name box, enter a name.
    5. Click the Input Channels list.
    6. In the Expression box, enter the CEL expression.
    7. Optional: In the Unit box, enter a unit.
    8. Optional: Turn on the Save to Asset toggle to save the Calculated Channel for future reuse.
    9. Click Add Calculated Channel.
  4. Optional: Add an Annotation to mark the anomaly for review or to share with your team:
    • In the Annotations tab, click Create new Annotation, select a type (Phase or Data Review), configure the fields, and click Add Annotation.
    • Alternatively, click Select X, drag over the time range in the Timeseries Panel, right-click the selection, and select Create Annotation.
  5. Optional: In Explore, click Share to send the exact state of your investigation to another engineer.
  6. Optional: Create a Rule to automatically detect the same anomaly in future Runs.

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Reference