Operators & thresholds
A rule compares a device tag against a threshold using one operator:
| Operator | Fires when value is… |
|---|---|
gt |
greater than the threshold |
lt |
less than the threshold |
gte |
greater than or equal |
lte |
less than or equal |
eq |
equal to the threshold |
Scope: a rule targets a specific device, or all devices (leave the device unset) to apply the same condition fleet-wide on a shared tag name. Set thresholds in the tag's engineering units — apply scaling on the tag so raw values and thresholds line up.
A rule's threshold vs. the tag's alarm limit. They are set separately. The alarm limit on the tag itself grades every reading Normal, Watch or Alert, colours the device's dot and badge and fills the Active alarms page; a rule is what sends an email, calls a webhook or runs an action, with its own severity and cooldown. Use both: put the limit on the tag, and write a rule at the same value (or at the Watch value, for an early nudge) for the deliveries you want. See Normal, Watch and Alert.