Timers and counters

The nodes in the Timers and counters categories of the Flow: Timer, Stairs Light, Trigger, Numeric Trigger, Astronomy Clock, Date/Hour, Repeat Command, Oscillator, Clock, and Counter, with properties, units of measure, and examples.

The nodes on this page bring time into logic: delays, automatic shutoff, pulses, schedules, sunrise and sunset, counts.

Node	Summary
Timer	Delays switching on and off.
Stairs Light	Timed light: turns off automatically after a set time.
Trigger	Turns a change into a pulse.
Numeric Trigger	Pulse when a number reaches a value.
Astronomy Clock	Day or night according to sunrise and sunset.
Date/Hour	Date, time, and day of the week.
Repeat Command	Repeats a pulse several times.
Oscillator and Clock	Continuous pulses or blinking.
Counter	Counts events.

Timer

Delays changes on input IN:

when IN turns on, OUT turns on after Delay Up seconds;
when IN turns off, OUT turns off after Delay Down seconds;
if IN changes again before the delay ends, the current delay is canceled.

Delays are in whole seconds; an empty field means 1 second, 0 means immediately.

Example — door left open: with Delay Up = 60, the Door alarm alarm triggers only if the door stays open for a full minute: if you close it before then, nothing happens. Delay Down = 2 turns the alarm off two seconds after closing.

Other uses: bathroom fan that starts 2 minutes after the light turns on and stops 5 minutes after it turns off; filter against false alarms from a sensor that turns on briefly.

Stairs Light

Turns the output on and switches it off automatically after Delay seconds (default 60). The Mode property determines how time is counted:

Mode	Operation	For
Presence	The light stays on while the input is on; the countdown starts when the input turns off.	Presence sensors that stay on while someone is there.
Pulse	Each time the input turns on, the countdown restarts from zero; input off is ignored.	Pushbuttons and motion sensors that send short pulses.

Flow Stairs light: Motion sensor on Stairs light with Delay 120 and Mode Pulse to Stairs lamp — Stairs Light in Pulse mode

The command is sent to the light only when the state changes: continuous detections do not flood the bus with "on" commands.

Example — stair light: a motion sensor in Pulse mode with Delay = 120: the light stays on for two minutes after the last movement.

Trigger

Turns an edge into a pulse (on and immediately off) on output OUT. The Cycle property selects the edge:

Up: pulse when the input changes from off to on;
Down: pulse when the input changes from on to off.

Example: a switch that stays on must start a scenario that needs a pulsed command; or "when the sun sets" (Down edge of the Astronomy Clock).

Numeric Trigger

Sends a pulse on OUT when the number on input IN becomes equal to Condition.

Example — tank full: when the water level reaches 100%, the Tank full pulse is generated, which can stop the pump or send a notification.

For a threshold (greater than, less than) use an IF followed by a Trigger.

Astronomy Clock

Calculates sunrise and sunset for the plant location: output Day is on during the day and off at night. The calculation updates every 10 seconds.

Enter latitude and longitude in Coordinates, separated by a comma, with a decimal point: for example 45.55, 11.55 for Vicenza. Coordinates can be found on any map (in Google Maps, right-click on the point).

Check the coordinates carefully: if the field is empty or entered incorrectly, the node uses point 0, 0 (in the Atlantic Ocean, on the equator) and sunrise and sunset will be wrong without any warning. After changing the coordinates, reload the flows with Upload.

Typical uses: shutters that close at sunset, garden lights on only at night, signs off during the day.

Date/Hour

Provides the server date and time, updated every second:

Output	Value
Seconds, Minute, Hour	Seconds (0–59), minutes (0–59), hours (0–23).
Day, Month, Year	Day of the month, month (1–12), year.
Week	Week number of the year.
Weekday	Day of the week in English: `Monday`, `Tuesday`… `Sunday`.
Daylight Savings	On when daylight saving time is in effect.

Flow Date / Hour: outputs Hour, Weekday and Daylight Savings to three components — The Date/Hour node outputs

Example — time scheduling: an IF Equal between Hour and the number 7 turns the heating on at 7; a second IF Equal between Weekday and the text Sunday excludes Sunday.

The outputs of Date/Hour are sent every second, even if the value does not change. Place an IF and a Trigger before a command to the system, so the command is sent only once.

Repeat Command

When the Trigger input turns on, the Trigger output sends a series of pulses: the first immediately, then another Repeat pulses, spaced Delay seconds apart. With Repeat = 2, a total of 3 pulses are output.

Example: repeat a command to a radio device that sometimes does not receive the first signal, or a sound signal repeated three times.

Oscillator and Clock

Flow Oscillator - Clock: Every second on a Counter Seconds and Blink 500 ms to Blinking lamp — Oscillator feeding a counter and Clock making an indicator blink

They generate a continuous signal, with no inputs, from the moment the flow starts:

Oscillator sends an pulse on the Trigger output every Timer milliseconds (minimum 100);
Clock switches on and off on the Trigger output every Delay milliseconds (from 100 to 100,000, default 1000).

Example: the Oscillator at 1000 ms connected to a Counter counts the elapsed seconds; the Clock at 500 ms makes an alarm indicator blink.

Do not connect Oscillator and Clock with short times directly to plant components: each pulse becomes a bus command. Use them for counting, for making virtual indicators blink, or with long times.

Counter

Counts the rising edges of the Trigger input and places the count on the Value output.

Property / input	Meaning
Enabled	The counter counts only when it is on.
Trigger	Each transition from off to on counts as one increment.
Reset	Resets the count to the Preset value. While it remains on, counting is stopped.
Preset	The starting value (default 0): with Preset = 0, the first event gives 1.
Up / Down	Counts up or down.
OUT	A pulse at each count.
Value	The current count.

Flow Counter: Enabled, Pulse and Reset on a Counter Visitors with Counted and Count outputs — The Counter as a people counter

Example — people counter: a photocell at the shop entrance on Trigger, the count on an app Info component, Reset at 00:00 with the Date/Hour node.

Other uses: with Down and Preset = 10, a countdown of available entries; with an IF on the Value output, maintenance every 500 pump cycles.