Read a live plant value correctly
Check identity, unit, quality and freshness before using a displayed value.
Before using this guide
Confirm your site, role and source revision. Follow the local procedure and responsible engineer for physical actions.
Five checks
A visually plausible value can still be stale, simulated, uncertain or mapped to the wrong equipment.
- Confirm the site and asset.
- Read the tag name/code and engineering unit.
- Check quality and source/received timestamps.
- Compare the value with the expected operating range and a recent trend.
- Record a decision only with the exact time range and supporting source.
If something looks wrong
Check before proceeding
- Check gateway health and historian continuity.
- Escalate an apparent unsafe plant condition through the site operating procedure immediately.
- Do not modify a PLC from this screen.