ACTION Triggers

Overview

Every Action needs a trigger—the event that starts its execution. Choosing the right trigger type determines how your automation responds to real-world conditions.

Think of triggers like different ways to start your car. A time-based trigger is like an auto-start that warms up your car every morning at 7 AM. A topic-based trigger is like pushing the start button when you get in. A callable action is like asking someone else to start it for you.

When to Use Each Type

Trigger Type	Use When	Example
Time-Based (`ON EVERY`, `ON TIMESTAMP`)	You need a clock-driven schedule (interval or wall-clock)	Heartbeats, polling, shift windows, one-shot cutovers
Topic-Based (`ON TOPIC`)	You need to react when data arrives	Sensor processing, command handling
Initialization (`ON START`)	You need to run logic once when the broker starts	Bootstrap UNS structure, set default config values
Callable (no trigger)	You need reusable logic invoked by other actions	Utility functions, shared calculations

Time-Based Triggers

LoT supports several time-based trigger forms. All of them use the ON keyword and run the action’s DO block automatically—no MQTT message is required to fire them. Together they cover recurring intervals, calendar rules (a specific weekday, Monday–Friday, or Saturday–Sunday), daily wall-clock times, and single one-shot executions.

Quick reference

Syntax	Pattern	Recurs?
`ON EVERY` N UNIT	Every N seconds, minutes, hours, and so on	Yes — indefinitely
`ON EVERY` DAY `AT` `"HH:mm"`	Named weekday at a fixed local time	Yes — every week
`ON EVERY WEEKDAY AT` `"HH:mm"`	Monday–Friday at a fixed local time	Yes — every weekday
`ON EVERY WEEKEND AT` `"HH:mm"`	Saturday–Sunday at a fixed local time	Yes — every weekend
`ON TIMESTAMP` `"HH:mm:ss"`	Every day at a fixed local time	Yes — every day
`ON TIMESTAMP` `"dd-MM-yyyy HH:mm:ss"`	Exact date and time	No — one-shot

Time zone: For HH:mm and HH:mm:ss in ON EVERY … AT and in daily ON TIMESTAMP, values are interpreted in the local time of the machine running the broker, then converted to UTC internally. The action is scheduled for the correct wall-clock time across daylight saving changes. The one-shot form dd-MM-yyyy HH:mm:ss is interpreted as UTC, as described below.

Structured payloads: PUBLISH TOPIC does not support inline JSON object literals. For multi-field records, define a COLLAPSED model and use PUBLISH MODEL … TO … WITH (see Publishing Models). The timed-action examples below use that pattern.

1. `ON EVERY` N UNIT — fixed interval

Fires repeatedly every N units of time. Common for monitoring, polling, and heartbeats.

DEFINE ACTION <Name>
ON EVERY <N> <UNIT> DO
    -- body

Supported units

Keyword(s)	Example
`MILLISECOND` / `MS`	`ON EVERY 500 MS`
`SECOND` / `SECONDS`	`ON EVERY 30 SECONDS`
`MINUTE` / `MINUTES`	`ON EVERY 5 MINUTES`
`HOUR` / `HOURS`	`ON EVERY 1 HOUR`
`DAY` / `DAYS`	`ON EVERY 1 DAY`
`WEEK` / `WEEKS`	`ON EVERY 2 WEEKS`
`MONTH` / `MONTHS`	`ON EVERY 1 MONTH`
`YEAR` / `YEARS`	`ON EVERY 1 YEAR`

Singular and plural unit names are interchangeable (for example, 1 SECOND and 1 SECONDS). ON EVERY 1 DAY fires every 24 hours from the last run; for the same clock time every calendar day, use daily ON TIMESTAMP instead.

DEFINE ACTION SystemHeartbeat
ON EVERY 5 SECONDS DO
    PUBLISH TOPIC "system/heartbeat" WITH "alive"
    PUBLISH TOPIC "system/heartbeat/timestamp" WITH TIMESTAMP "UTC"

DEFINE ACTION PollMachineTemperature
ON EVERY 30 SECONDS DO
    SET "temp" WITH GET TOPIC "machine/sensor/temperature"
    IF {temp} > 85 THEN
        PUBLISH TOPIC "alerts/temperature/high" WITH {temp}
    PUBLISH TOPIC "machine/temperature/last_check" WITH TIMESTAMP "UTC"

DEFINE ACTION FastSensorSample
ON EVERY 500 MS DO
    PUBLISH TOPIC "sensors/vibration/sample" WITH GET TOPIC "sensors/vibration/raw"

2. `ON EVERY` DAY `AT` — weekly, specific day

Fires once per week on the named weekday at the given local time. Use "HH:mm" or "HH:mm:ss"; seconds are optional.

Keyword	Fires on
`MONDAY` … `SUNDAY`	That weekday each week

DEFINE ACTION <Name>
ON EVERY MONDAY AT "08:00:00" DO
    -- body

DEFINE MODEL ProductionWeeklyReport COLLAPSED
    ADD STRING "week"
    ADD INT "total_parts"
    ADD INT "total_rejects"

DEFINE ACTION WeeklyProductionReport
ON EVERY MONDAY AT "08:00:00" DO
    SET "week_total" WITH GET TOPIC "factory/line1/parts_produced"
    SET "week_rejects" WITH GET TOPIC "factory/line1/rejects"
    PUBLISH MODEL ProductionWeeklyReport TO "reports/weekly/production" WITH
        week = TIMESTAMP "UTC"
        total_parts = {week_total}
        total_rejects = {week_rejects}
    PUBLISH TOPIC "factory/line1/parts_produced" WITH 0
    PUBLISH TOPIC "factory/line1/rejects" WITH 0

3. `ON EVERY WEEKDAY AT` — Monday–Friday

Fires Monday through Friday at the same local time—one action instead of five separate daily schedules.

DEFINE MODEL ShiftMorningBriefing COLLAPSED
    ADD STRING "line_status"
    ADD STRING "pending_orders"
    ADD STRING "shift_start"

DEFINE ACTION ShiftStartBriefing
ON EVERY WEEKDAY AT "07:30" DO
    SET "line_status" WITH GET TOPIC "factory/line1/status"
    SET "pending_orders" WITH GET TOPIC "erp/orders/pending"
    PUBLISH MODEL ShiftMorningBriefing TO "shift/briefing/morning" WITH
        line_status = {line_status}
        pending_orders = {pending_orders}
        shift_start = TIMESTAMP "UTC"

4. `ON EVERY WEEKEND AT` — Saturday and Sunday

Fires on both weekend days at the specified local time—useful for maintenance windows or weekend-only reporting.

DEFINE ACTION WeekendMaintenanceWindow
ON EVERY WEEKEND AT "06:00:00" DO
    PUBLISH TOPIC "maintenance/window/open" WITH "true"
    PUBLISH TOPIC "maintenance/window/start" WITH TIMESTAMP "UTC"
    PUBLISH TOPIC "notifications/maintenance" WITH "Weekend maintenance window is now open"

5. `ON TIMESTAMP` — daily fixed time

Fires every day at the given local wall-clock time. Unlike ON EVERY 1 DAY, this tracks clock time, not elapsed time since the broker or last run started.

DEFINE ACTION <Name>
ON TIMESTAMP "08:00:00" DO
    -- body

"HH:mm" without seconds is accepted.

DEFINE ACTION DailyCounterReset
ON TIMESTAMP "00:00:00" DO
    PUBLISH TOPIC "factory/line1/parts_produced" WITH 0
    PUBLISH TOPIC "factory/line1/rejects" WITH 0
    PUBLISH TOPIC "factory/line1/day_start" WITH TIMESTAMP "UTC"

6. `ON TIMESTAMP` — one-shot, exact date and time

Fires once at the exact instant given, then never again (the scheduler moves the next run far into the future). Format is strictly dd-MM-yyyy HH:mm:ss (day–month–year). The timestamp is treated as UTC.

DEFINE ACTION SystemCutoverNotice
ON TIMESTAMP "01-04-2026 06:00:00" DO
    PUBLISH TOPIC "system/cutover/notice" WITH "New firmware version going live in 1 hour"
    PUBLISH TOPIC "notifications/all" WITH "Scheduled maintenance begins at 07:00 UTC"

Combination patterns

Real systems often split schedules across several actions—one trigger per concern.

Fast poll + daily summary

DEFINE MODEL DailyTemperatureReport COLLAPSED
    ADD DOUBLE "max"
    ADD DOUBLE "min"
    ADD STRING "date"

DEFINE ACTION SensorPoll
ON EVERY 10 SECONDS DO
    SET "value" WITH GET TOPIC "sensors/temperature/raw"
    PUBLISH TOPIC "sensors/temperature/current" WITH {value}

DEFINE ACTION DailySensorSummary
ON TIMESTAMP "00:00:00" DO
    SET "max" WITH GET TOPIC "sensors/temperature/max"
    SET "min" WITH GET TOPIC "sensors/temperature/min"
    PUBLISH MODEL DailyTemperatureReport TO "reports/daily/temperature" WITH
        max = {max}
        min = {min}
        date = TIMESTAMP "UTC"
    PUBLISH TOPIC "sensors/temperature/max" WITH 0
    PUBLISH TOPIC "sensors/temperature/min" WITH 0

Weekday operations + weekend maintenance

DEFINE ACTION WeekdayProductionStart
ON EVERY WEEKDAY AT "06:00" DO
    PUBLISH TOPIC "factory/line1/mode" WITH "production"
    PUBLISH TOPIC "factory/line1/shift_start" WITH TIMESTAMP "UTC"

DEFINE ACTION WeekendMaintenance
ON EVERY WEEKEND AT "07:00" DO
    PUBLISH TOPIC "factory/line1/mode" WITH "maintenance"
    PUBLISH TOPIC "notifications/maintenance/start" WITH TIMESTAMP "UTC"

Weekly reset + daily snapshot + live throughput

DEFINE MODEL DashboardThroughput COLLAPSED
    ADD INT "parts"
    ADD DOUBLE "rate_per_min"
    ADD INT "updated"

DEFINE ACTION WeeklyKpiReset
ON EVERY MONDAY AT "00:00:00" DO
    PUBLISH TOPIC "kpi/weekly/parts_produced" WITH 0
    PUBLISH TOPIC "kpi/weekly/reset_time" WITH TIMESTAMP "UTC"

DEFINE ACTION DailyKpiSnapshot
ON TIMESTAMP "23:59:00" DO
    SET "daily_parts" WITH GET TOPIC "factory/line1/parts_produced"
    PUBLISH TOPIC "kpi/daily/snapshot" WITH {daily_parts}
    PUBLISH TOPIC "kpi/daily/snapshot_time" WITH TIMESTAMP "UTC"

DEFINE ACTION LiveThroughput
ON EVERY 1 MINUTE DO
    SET "parts" WITH GET TOPIC "factory/line1/parts_produced"
    SET "rate" WITH GET TOPIC "factory/line1/production_rate"
    PUBLISH MODEL DashboardThroughput TO "dashboard/live/throughput" WITH
        parts = {parts}
        rate_per_min = {rate}
        updated = TIMESTAMP "UNIX"

One-shot cutover + ongoing heartbeat

DEFINE ACTION CutoverActivation
ON TIMESTAMP "01-07-2026 06:00:00" DO
    PUBLISH TOPIC "system/version" WITH "2.0"
    PUBLISH TOPIC "system/cutover/complete" WITH TIMESTAMP "UTC"

DEFINE ACTION V2Heartbeat
ON EVERY 30 SECONDS DO
    SET "ver" WITH GET TOPIC "system/version"
    IF {ver} EQUALS "2.0" THEN
        PUBLISH TOPIC "system/v2/heartbeat" WITH "running"

Error handling

If a time string does not match an expected format, the broker logs an error similar to: Invalid DATE_TIME format: <value>. Expected formats:

dd-MM-yyyy HH:mm:ss (one-time)
HH:mm:ss / HH:mm (daily)
Weekly forms using a day name with AT and a time string

Errors are also published (retained) to: $SYS/Coreflux/Actions/<ActionName>/Error Subscribe to $SYS/Coreflux/Actions/+/Error to observe failures from any action.

At a glance — valid time triggers

ON EVERY 500 MS DO
ON EVERY 10 SECONDS DO
ON EVERY 5 MINUTES DO
ON EVERY 1 HOUR DO
ON EVERY 1 DAY DO
ON EVERY 1 WEEK DO
ON EVERY 1 MONTH DO
ON EVERY MONDAY AT "08:00:00" DO
ON EVERY WEEKDAY AT "07:30" DO
ON EVERY WEEKEND AT "06:00" DO
ON TIMESTAMP "07:00" DO
ON TIMESTAMP "00:00:00" DO
ON TIMESTAMP "25-12-2026 09:00:00" DO

More examples

System heartbeat

DEFINE ACTION SystemHeartbeat
ON EVERY 5 SECONDS DO
    PUBLISH TOPIC "system/status" WITH "online"
    PUBLISH TOPIC "system/timestamp" WITH TIMESTAMP "UTC"

Counter with state

DEFINE ACTION IncrementCounter
ON EVERY 10 SECONDS DO
    IF GET TOPIC "counter/value" == EMPTY THEN
        PUBLISH TOPIC "counter/value" WITH 0
    ELSE
        PUBLISH TOPIC "counter/value" WITH (GET TOPIC "counter/value" + 1)

Topic-Based Triggers

Use ON TOPIC to execute actions when MQTT messages arrive:

DEFINE ACTION ProcessMessage
ON TOPIC "input/data" DO
    PUBLISH TOPIC "output/data" WITH PAYLOAD

Wildcard Patterns

LoT supports MQTT wildcards for flexible topic matching:

Single-Level (+)
Multi-Level (+/+)

The + wildcard matches exactly one topic level:

DEFINE ACTION SensorRouter
ON TOPIC "sensors/+/temperature" DO
    // POSITION 1="sensors", POSITION 2=wildcard (sensor_id), POSITION 3="temperature"
    SET "sensor_id" WITH TOPIC POSITION 2
    PUBLISH TOPIC "processed/" + {sensor_id} + "/temp" WITH PAYLOAD

Matches: sensors/room1/temperature, sensors/room2/temperature

Does NOT match: sensors/building1/floor2/temperature (too many levels)

Use multiple single-level wildcards for deeper hierarchies:

DEFINE ACTION FactoryMonitor
ON TOPIC "factory/+/+/status" DO
    // POSITION 1="factory", POSITION 2=line_id, POSITION 3=machine_id, POSITION 4="status"
    SET "line_id" WITH TOPIC POSITION 2
    SET "machine_id" WITH TOPIC POSITION 3
    
    PUBLISH TOPIC "monitoring/" + {line_id} + "/" + {machine_id} WITH PAYLOAD

Matches: factory/line1/machine1/status, factory/line2/press3/status

Does NOT match: factory/line1/status (missing one level), factory/status (missing two levels)

Initialization Triggers

Use ON START to execute logic exactly once when the broker starts or when the action is first deployed. This is the right place to bootstrap a Unified Namespace (UNS) structure, publish retained default configurations, and log startup events.

DEFINE ACTION InitUNSRoot
ON START DO
    KEEP TOPIC "config/uns_root" WITH "factory/lisbon"
    KEEP TOPIC "factory/info/name" WITH "Lisbon Plant"
    KEEP TOPIC "factory/info/timezone" WITH "Europe/Lisbon"
    PUBLISH TOPIC "system/log" WITH "UNS root initialised"

Key characteristics:

Runs exactly once per broker start — not on a schedule, not on a message
KEEP TOPIC publishes with the retain flag so the value is delivered to any future subscriber immediately on connection
Use it to set default configuration values and retained state that must survive restarts
There is no ON STOP equivalent — ON START is the correct place for setup logic

Callable Actions

Actions without an event trigger are callable—they execute only when explicitly invoked by other actions or via system commands.

Basic Callable Action

DEFINE ACTION CacheUpdater
DO
    KEEP TOPIC "cache/latest" WITH (GET TOPIC "data/current")
    PUBLISH TOPIC "cache/updated" WITH TIMESTAMP "UTC"

Callable Action with Parameters

Callable actions can accept input parameters and return values:

DEFINE ACTION CalculateAverage
INPUT value1 AS DOUBLE
INPUT value2 AS DOUBLE
DO
    SET "sum" WITH ({value1} + {value2})
    SET "avg" WITH ({sum} / 2)
RETURN
    OUTPUT avg

Invoking Callable Actions

From Another Action
Via Command Topic

Use CALL ACTION to invoke from within another action. This is the primary way to reuse logic across your automation:

DEFINE ACTION ProcessSensorPair
ON TOPIC "sensors/pair/data" DO
    SET "temp1" WITH (GET JSON "sensor1" IN PAYLOAD AS DOUBLE)
    SET "temp2" WITH (GET JSON "sensor2" IN PAYLOAD AS DOUBLE)
    
    CALL ACTION CalculateAverage
        WITH value1 = {temp1}, value2 = {temp2}
        RETURN result
    
    PUBLISH TOPIC "sensors/average" WITH {result}

Publish a message to the system command topic to invoke an action externally:Topic: $SYS/Coreflux/CommandPayload: -runAction CacheUpdaterUse any MQTT client to publish this message. The action executes immediately upon receiving the command.

Comparing Trigger Types

Aspect	Time-Based	Topic-Based	ON START	Callable
Trigger	Clock interval or schedule	MQTT message	Broker startup	Manual command
Frequency	Interval, daily, weekly, or once	Event-driven	Once	On-demand
Payload Access	No	Yes (`PAYLOAD`)	No	Via parameters
Best For	Monitoring, reporting	Data processing	Initialization	Reusable utilities

Quick Start

Developing and Managing Coreflux

Coreflux MQTT Broker

LoT Language

Product Updates

Overview

When to Use Each Type

Time-Based Triggers

Quick reference

1. `ON EVERY` N UNIT — fixed interval

Supported units

2. `ON EVERY` DAY `AT` — weekly, specific day

3. `ON EVERY WEEKDAY AT` — Monday–Friday

4. `ON EVERY WEEKEND AT` — Saturday and Sunday

5. `ON TIMESTAMP` — daily fixed time

6. `ON TIMESTAMP` — one-shot, exact date and time

Combination patterns

Error handling

At a glance — valid time triggers

More examples

Topic-Based Triggers

Wildcard Patterns

Initialization Triggers

Callable Actions

Basic Callable Action

Callable Action with Parameters

Invoking Callable Actions

Comparing Trigger Types

Next Steps

Operations

Python Integration

​Overview

​When to Use Each Type

​Time-Based Triggers

​Quick reference

​1. ON EVERY N UNIT — fixed interval

​Supported units

​2. ON EVERY DAY AT — weekly, specific day

​3. ON EVERY WEEKDAY AT — Monday–Friday

​4. ON EVERY WEEKEND AT — Saturday and Sunday

​5. ON TIMESTAMP — daily fixed time

​6. ON TIMESTAMP — one-shot, exact date and time

​Combination patterns

​Error handling

​At a glance — valid time triggers

​More examples

​Topic-Based Triggers

​Wildcard Patterns

​Initialization Triggers

​Callable Actions

​Basic Callable Action

​Callable Action with Parameters

​Invoking Callable Actions

​Comparing Trigger Types

​Next Steps

Operations

Python Integration

Overview

When to Use Each Type

Time-Based Triggers

Quick reference

1. `ON EVERY` N UNIT — fixed interval

Supported units

2. `ON EVERY` DAY `AT` — weekly, specific day

3. `ON EVERY WEEKDAY AT` — Monday–Friday

4. `ON EVERY WEEKEND AT` — Saturday and Sunday

5. `ON TIMESTAMP` — daily fixed time

6. `ON TIMESTAMP` — one-shot, exact date and time

Combination patterns

Error handling

At a glance — valid time triggers

More examples

Topic-Based Triggers

Wildcard Patterns

Initialization Triggers

Callable Actions

Basic Callable Action

Callable Action with Parameters

Invoking Callable Actions

Comparing Trigger Types

Next Steps