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After completing this workflow, you can reference external file data directly in Rule and Calculated Channel expressions to compare telemetry against thresholds, apply calibration values, or use configuration data that changes between Runs without hardcoding values in your expressions.

Before you begin

  • You have an Asset or a Run with at least one file attached in a supported format.
  • You have an existing Rule or Calculated Channel to edit, or you are ready to create a new one.

How file references work

Rule and Calculated Channel expressions can access data from files attached to an Asset or a Run using two functions: assetFile() and runFile().
  • assetFile("filename.format") reads a file attached to the Asset the Rule or Calculated Channel is configured for.
    • The file is verified when the expression is created or edited.
    • Use this for data that stays the same across Runs, such as hardware limits, calibration offsets, or hardware specifications.
  • runFile("filename.format") reads a file attached to the Run being evaluated.
    • The file is resolved at evaluation time, when a Rule is evaluated against a Run, or when a Calculated Channel is evaluated against a Run.
    • Use this for data that changes between Runs, such as test parameters, environmental conditions, or per-session acceptance criteria.
Once a file is loaded, you access specific values using bracket notation. The syntax depends on the file format. For supported formats and syntax, see File functions.

Reference a file in an expression

  1. Attach a file to the Asset or the Run you want the expression to reference.
  2. Create a new Rule or Calculated Channel, or open an existing one to edit.
  3. In the Expression editor, use assetFile("filename") or runFile("filename") to reference the file by name.
  4. Use bracket notation to index into the specific value.
  5. Verify the expression:
    • Rules: Preview the Rule against an existing Run to confirm the expression resolves correctly.
    • Calculated Channels: Preview the Calculated Channel against a Run to confirm the expression resolves correctly.

Examples

Rules

Calculated Channels

Reference