Why is my device offline?
A device is online if we've heard from it recently, where "recently" is based on how often that device is expected to report — at least 90 seconds, and longer for devices that report slowly. Common causes of an unexpected offline state:
- The device (or its gateway) lost network or power.
- The gateway went offline, which marks all its child devices offline (LWT cascade).
- A direct MQTT or webhook device reports less often than every 90 seconds. We can't see the reporting interval of a device that pushes to us, so we assume 90 s — set a reporting grace period on the device to match its real interval.
Devices connected through a gateway are unaffected by their publish interval: the gateway sends a presence heartbeat every ~10 seconds no matter how rarely the device itself publishes. An RS485 meter set to publish every 5 minutes still stays green.
Online status lives in memory, not the database, so it resets if our cache is flushed — devices re-appear as soon as they publish again. See device shows offline for a full checklist.