My device shows offline

Work through these:

1. Power & network — is the device (and its gateway) powered and connected?
2. Publish interval — if it reports less often than every 90 s, it'll flip offline between messages. Increase frequency.
3. Gateway — if the parent gateway is offline, all its children are too. Fix the gateway first.
4. Credentials/topic — for mqtt-direct, confirm the username/password and base topic are correct.
5. Faults — check the Events feed for modbus/timeout, */fault, or */poll-error (see fault events).
6. Polling auto-disabled — for HTTP, SNMP and Modbus-TCP devices (which we poll directly), see below.

Presence resets if our cache is flushed; a healthy device re-appears within ~90 s of its next message.

Why did my HTTP / SNMP / Modbus-TCP device stop polling?

These three protocols are polled directly by Synacl on the interval you configured. To protect the platform from endlessly hammering a dead endpoint, we automatically disable polling for a device after 10 consecutive failed attempts. When this happens you'll see a device/poll-disabled event and a "Polling disabled" badge on the device page — no further requests are made until you re-enable it.

To recover:

1. Fix the underlying cause — wrong host/IP/port, an unreachable network, bad credentials, or a wrong OID / register / JSON path. The last error is shown on the device page.
2. Open the device and click Re-enable polling. Querying resumes within about a minute.

If it fails again 10 times in a row it will be disabled again — that's expected until the device or its connection settings are corrected.