Tutorial: Triggering devices from cues

Learn how to use manual, automatic, timed, MIDI, OSC, HTTP, cue-based, and device-state triggers to synchronize stage devices in Arthoff.

This tutorial explains how Arthoff can control lighting, audio, cameras, and stage-effect devices through triggers attached to cues. It covers manual and automatic triggering, delays, and external signals used in theatre, concerts, and corporate events.

What is a trigger in Arthoff?

A trigger defines when a cue is activated. By default, a cue is triggered manually by pressing Space or clicking Next in presenter mode. Other trigger types make it possible to automate part of a show or synchronize Arthoff with external systems.

Trigger types

Trigger	Description	Example
Manual	The cue waits for a user action such as Space, click, or jump.	A lighting operator chooses the exact moment for a lighting change.
Auto after previous	Starts after the previous cue finishes.	A lighting change follows an actor's line automatically.
Time delay	Starts after a configured delay.	Smoke starts 2 seconds after confetti.
MIDI signal	Waits for a selected MIDI Note or CC message.	A drum pad triggers a strobe cue.
OSC signal	Waits for an OSC packet with the configured address and value.	Another console sends `/lighting/speaker_mode`.
HTTP / Webhook	Uses an HTTP GET/POST request for an external endpoint.	A relay API starts a smoke machine.
Cue-based	Starts when another selected cue finishes.	A screen cue follows a lighting cue rather than the immediately previous cue.
Device state	Starts when a connected device reports a selected state.	An audio threshold triggers reactive lighting.

Note

Not every trigger type is available for every cue type. Some options, including MIDI and OSC, require a compatible device or integration. Unavailable options are disabled in the cue editor.

Where to configure a trigger

Open a cue in the editor and expand the Trigger section. The available fields change depending on the selected trigger type.

Example 1: Automatic lighting change after an actor's line

Scenario: An actor finishes a monologue and the stage should immediately turn red.

Find the dialogue cue containing the actor's final line.

Open its Trigger settings.

Change the trigger from Manual to Auto after previous. If a short pause is needed instead, choose Time delay, for example 0.5 s.

Create the following Lighting cue with the values for the red wash.

Configure the lighting cue to continue automatically if the transition should happen without another operator action.

The result is a lighting transition that follows the dialogue without requiring a separate button press at the moment of the change.

Example 2: Strobe synchronized with a drum pad

Scenario: A drummer hits a MIDI pad and the strobe should flash at the same moment.

Connect the MIDI controller and add it in Devices as a MIDI input or a generic MIDI device.

Create a Lighting cue for the strobe. For example, set the strobe channel to 255, use a 0 fade time, and use snapshot-style output.

Open the cue's Trigger settings and choose MIDI signal.

Configure the MIDI message, for example Note On, note 36 (C2), MIDI channel 10, and an optional threshold for CC input.

Save the cue and test the pad input before the live show.

Each matching MIDI message can now trigger the cue without intervention from the lighting operator.

Example 3: PTZ camera change from an OSC signal

Scenario: During a presentation, a lighting console enters a speaker look and the camera should move to a close-up of the presenter.

Add the PTZ camera as a Camera or generic OSC device and configure its IP address and listening port, for example 8001.

Create a Camera cue with values such as Pan 45°, Tilt -10°, Zoom 3x, transition Fade, duration 1 s.

Set the trigger to OSC signal.

Configure an OSC address such as /lighting/speaker_mode, with value 1 and the appropriate data type.

Configure the lighting console to send that OSC message to the computer running Arthoff when speaker mode is activated.

If the lighting console cannot send OSC directly, a bridge can translate another protocol such as Art-Net or MIDI into OSC.

Example 4: Smoke after confetti with a delay

Scenario: Confetti fires first, then smoke starts 1.5 s later.

Create a Custom cue for the confetti device, for example OSC address /fx/confetti with value 1.

Create the following Custom cue for smoke, for example OSC address /fx/smoke with value 1.

Open the smoke cue's trigger settings and choose Time delay.

Set the delay to 1.5 s and make it relative to the previous cue.

The two effects remain in one deterministic sequence while preserving the desired visual offset.

Example 5: Move to the next section after a fixed time

For timed corporate segments, a timer-style cue can be configured with a delay and followed by a cue-based or automatic trigger that jumps or advances to the next section. This is useful when a segment has a strict duration and does not require manual advancement.

Advanced trigger patterns

Combining conditions

Where supported by the selected integration, several conditions can be combined using logical AND or OR rules. This is useful when a cue should require both a timing condition and a device signal, or accept one of several equivalent external signals.

Triggering cues from other cues

Cue-based triggers do not have to reference the immediately previous cue. This allows technical events to be synchronized across different cue types while keeping the script readable.

Testing without real devices

Use presenter test mode or dry-run mode to verify trigger order before sending commands to physical hardware. For external triggers, confirm the incoming MIDI, OSC, or HTTP data separately before enabling real device output.

Safety

External triggers can activate real equipment without an operator pressing a button. Test them with outputs disabled first, especially when machinery, pyrotechnics, smoke, or other stage effects are involved.

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