Frequently asked questions
Data and storage
Section titled “Data and storage”Why do my messages not appear in Messages? Messages are only stored through a rule. Open the channel and choose Store in Internal DB (SenML). Also check Rules → Executions for errors, and make sure the payload format matches the output (SenML or SenFlat for the SenML output).
Live mode shows messages but the table is empty. Why? Live shows every incoming message, including those that are not stored. The table only has messages stored by a rule.
How long is data kept? 365 days by default (compressed after 7 days). The server administrator can change this.
Can I store to my own database? Yes, through the PostgreSQL output in a rule (including TimescaleDB). See External TimescaleDB SQL and Rule to PostgreSQL.
Why is the latest value or chart empty? A free-form JSON payload does not count as a metric. Use SenML or SenFlat and store through Internal DB (SenML).
The unit of a SenFlat metric is empty. Why? SenFlat carries no unit. Fill it from the Metric Catalog (the Load defaults button).
Devices
Section titled “Devices”A device is refused by the broker.
Check: username = the device ID, password = the device key, client_id starts with the device ID (production), and the device is not disabled. If it connects but is dropped on publish, the device has no publish connection to that channel. See Connecting devices.
I lost the device key. A key cannot be shown again. On the device detail choose Generate new key or Set own key.
How do I send many sensors’ data over one connection?
Use a gateway (Gateways) and SenML or SenFlat with a bn or id per sensor. For history and untrusted clocks use SenFlat v2.
Can my device use HTTP only, without MQTT? The main device path is MQTT. Third-party applications can send messages to a channel through the REST API.
Can I test without a device? Yes, use the simulator.
Access and accounts
Section titled “Access and accounts”I cannot create a new workspace, device, or channel. Your account quota has probably been reached. Ask the platform administrator to raise it.
I get 404 for a workspace I thought existed.
Celestian answers 404 to non-members (so a workspace’s existence does not leak). Ask to be invited, or make sure your account has workspace.read.
How do I give access to only some devices? Put the devices into a group and grant permissions on the group, or use per-object or per-tag permissions in roles.
My account is locked after a wrong password. Wait out the block, or ask a workspace admin to choose Unlock login in Members.
Can an API token manage members and roles? No. A token may not have access-management actions.
Rules and alarms
Section titled “Rules and alarms”My rule cannot be enabled. The graph is incomplete or invalid (it needs 1 Input, at least 1 Logic, at least 1 Output, all connected). See the per-node errors.
My Lua script is rejected.
A script must have the form function logicFunction() … end and return logicFunction().
An alarm does not repeat on every message. That is deduplication: one active alarm per rule, device, and measurement. A recurrence only increases the counter.
A rule does not process old messages. A rule only processes messages received since it was enabled.
Dashboards and reports
Section titled “Dashboards and reports”Several devices use the same metric name and my chart is mixed. Pick the Device on the widget source.
Can a dashboard be shared without signing in?
Yes, the Public option produces a read-only link /share/d/<token>. Some widgets are unavailable in the public view. See Dashboards.
A PDF report fails. The administrator may not have installed the PDF service yet; CSV is still available.