Variable speed PIUs: add example files fieldnames and revise error message

[lymereJ]

Pull request overview

• Address this comment: Variable speed fan powered induction boxes #10368 (comment)

NOTE: ENHANCEMENTS MUST FOLLOW A SUBMISSION PROCESS INCLUDING A FEATURE PROPOSAL AND DESIGN DOCUMENT PRIOR TO SUBMITTING CODE

Pull Request Author

Add to this list or remove from it as applicable. This is a simple templated set of guidelines.

• Title of PR should be user-synopsis style (clearly understandable in a standalone changelog context)
• Label the PR with at least one of: Defect, Refactoring, NewFeature, Performance, and/or DoNoPublish

Reviewer

This will not be exhaustively relevant to every PR.

• Perform a Code Review on GitHub
• If branch is behind develop, merge develop and build locally to check for side effects of the merge
• If defect, verify by running develop branch and reproducing defect, then running PR and reproducing fix
• If feature, test running new feature, try creative ways to break it
• CI status: all green or justified
• Check that performance is not impacted (CI Linux results include performance check)
• Run Unit Test(s) locally
• Check any new function arguments for performance impacts
• Verify IDF naming conventions and styles, memos and notes and defaults
• If new idf included, locally check the err file and other outputs

[github-actions]

⚠️ Regressions detected on macos-14 for commit 6f2b34f

Regression Summary

• EIO: 1
• ESO Big Diffs: 1
• Table Big Diffs: 1
• Table String Diffs: 1

• View Results
• Download Regressions

[github-actions]

⚠️ Regressions detected on macos-14 for commit e93e00f

Regression Summary

• EIO: 1
• ESO Big Diffs: 1
• Table Big Diffs: 1
• Table String Diffs: 1

• View Results
• Download Regressions