Skip to main content

​
Overview

Let’s discuss and create a Rule in Sift, which enables you to create logical conditions to evaluate your telemetry.

​
What are Rules

Rules in Sift are logical conditions, defined using the Common Expression Language (CEL), that evaluate telemetry across one or more Channels from an Asset to detect behaviors, anomalies, and threshold breaches in live and historical data.
  • When a Rule evaluates to true, it can create Annotations, send notifications, or be assigned to a user for follow-up
  • Rules support versioning and previewing against existing Run data

​
Preview and create a Rule

To better understand Rules, let’s create one that captures a specific behavior in a Channel from the low Earth orbit satellite (LEO) we explored in Tutorial 1. Specifically, we’ll create a Rule for the temperature Channel in the camera_1 subsystem that triggers an Annotation when the temperature exceeds 30 degrees Celsius. This ensures future datasets are automatically checked for similar anomalies and flagged for review.
  1. In Sift’s home page, click the Rules tab.
  2. Click New Rule.
  3. In the Rule name box, enter the following: 
    fl_tutorial_4_rule
  4. Replace fl (in fl_tutorial_4_rule) with your own initials.
  5. In the Asset name, select the Asset created in Tutorial 1.
    • For example: fl_tutorial_1_asset
  6. In the Input Channels list, select the following Channel:
    • camera_1.temperature
  7. In the Enter an expression box, enter: 
    $1 > 30
    • Channel references: Selected Channels are referenced in the expression using $1, $2, $3, and so on, in the order they appear in the Input Channels list. In this case, $1 refers to camera_1.temperature.
    • Functions: Expressions support a variety of built-in function types for different kinds of calculations. To browse all available functions, observe the Expression Syntax section.
  8. Click Select Run(s) to preview.
  9. Click the Run created in Tutorial 1.
    • For example: fl_tutorial_1_run
  10. Click Preview 1 Runs.
  11. Click Save.