Inject

Starts a flow. Every pipeline that is not triggered by the outside world begins here — on an interval, on a cron expression, or once when the pipeline starts.

Type: inject · Category: Common · Ports: no input · one output

When to use it

• Anything on a clock — hourly rollups, nightly exports, a poll every 30 seconds
• Priming a pipeline once at startup, to load configuration or take a first reading
• Giving yourself a Run button while building a flow

Reach for something else when

If the pipeline should react to a tag change, use Industrial I/O in subscribe mode; to an alarm, use the Alarm node; to an HTTP request, use REST API in ingress mode. Polling for something that could push to you wastes reads and adds latency.

Settings

Setting	Key	Purpose
Repeat	repeat	none, an interval, or a cron expression.
Interval	intervalValue / intervalUnit	How often, when repeating on an interval.
Cron	cronExpression	Calendar-aligned schedule.
Initial delay	initialDelay	Seconds to wait before the first fire.
Payload	payloadType / payloadValue	What to emit — a timestamp, a literal, an object.

Example — an hourly rollup at five past the hour

Repeat:  cron
Cron:    5 * * * *
Payload: timestamp

Out

{ "payload": 1786454700000, "topic": "" }

Interval or cron?

Use cron whenever the work is tied to the clock — shift boundaries, midnight rollups, the top of the hour. Use an interval when only the frequency matters.

An interval counts from pipeline start, so 3600s drifts against the wall clock every time the pipeline is restarted; 0 * * * * does not. If your hourly report has ever arrived at 10:47, this is why.

See also

• Execution & triggering