DALI Sensors & Input Devices (IEC 62386-301–304)

Introduction

Lighting control has evolved from simple wall switches to sophisticated sensor-driven systems that adjust light based on occupancy, daylight levels, and user preference. At the heart of this evolution is the DALI protocol (IEC 62386), which enables two-way communication between control devices and lighting gear.

Within DALI, input devices such as sensors, switches, and control panels are defined by IEC 62386-301 to 304, ensuring interoperability across manufacturers. These devices act as the “eyes and hands” of the system, detecting conditions and enabling user interaction, while DALI controllers and drivers execute the lighting responses.

This article provides a complete breakdown of DALI input devices, their standards, applications, advantages, and future trends.

Traditional vs. Digital Control Devices

Traditional Systems

Manual switches – simple on/off control.
Analog dimming (0–10V) – limited feedback, prone to voltage drop.
Stand-alone sensors – could turn lights on/off but not integrated with larger systems.

Limitations:

No central monitoring.
Inconsistent performance.
Rewiring required for reconfiguration.

DALI Input Devices

Sensors communicate digitally with the controller.
Devices can be reprogrammed via software (no rewiring).
Event-driven communication reduces bus traffic.
Feedback ensures system reliability.

IEC 62386-301 to 304 Standards Explained

The DALI-2 standard expanded input device support through specific parts of IEC 62386:

IEC 62386-301 – General Requirements for Input Devices
- Defines communication behavior of input devices.
- Ensures devices report their capabilities to the controller.
IEC 62386-302 – Push Buttons & Switches
- Covers traditional wall switches, multi-button panels, rotary dimmers.
- Allows event-based communication (e.g., short press, long press).
IEC 62386-303 – Occupancy Sensors
- Motion sensors (PIR, microwave, ultrasonic).
- Reports occupancy/detection events to DALI controllers.
- Supports configurable timeouts and sensitivity.
IEC 62386-304 – Light Sensors
- Measures ambient light (lux level).
- Enables daylight harvesting and constant light control.
- Reports real-time lux values digitally.

???? Together, these standards ensure multi-vendor compatibility for input devices.

How DALI Sensors Communicate with Controllers

Unlike analog sensors, which continuously send a variable voltage, DALI input devices send digital event messages when something changes:

A motion sensor sends “occupancy detected” to the controller.
A lux sensor sends an updated light value if ambient light changes.
A switch reports button press/release states.

Benefits of Event-Based Reporting

Reduces network traffic.
Faster system response.
More reliable and standardized feedback.

System Architecture

Components

Application Controller – interprets sensor input (Helvar Router, Tridonic SceneCOM).
Sensors – occupancy, daylight, switches.
Control Gear – LED drivers, ballasts.
Bus Power Supply – 16V DC for DALI line.

Wiring Rules

Max 64 devices per line (including input devices + drivers).
Two-wire, polarity-free DALI bus.
Max 300m bus length (1.5mm² cable).
Sensors share the same bus as luminaires.

Types of DALI Input Devices

1. Occupancy Sensors (IEC 62386-303)

Occupancy Sensors are input devices defined under IEC 62386-303, designed to detect presence or motion and send event-driven signals to a DALI controller for automated lighting control. Unlike stand-alone PIR or microwave sensors, occupancy sensors communicate digitally over the DALI bus, enabling flexible mapping to groups of luminaires, real-time feedback, and seamless integration with other devices. They can be configured to trigger on/off switching, dimming, or scene changes based on occupancy, making them ideal for energy savings in offices, classrooms, corridors, and restrooms.

PIR sensors – detect movement via infrared.
Microwave sensors – detect motion through walls/partitions.
Ultrasonic sensors – highly sensitive, detect minor movements.

Use Cases: Offices, classrooms, washrooms, corridors.

2. Daylight Sensors (IEC 62386-304)

Daylight Sensors, standardized under IEC 62386-304, are input devices that measure ambient light levels in lux and communicate digitally with the DALI controller to optimize artificial lighting. By monitoring natural daylight, these sensors enable daylight harvesting and constant light control, where luminaires automatically dim or brighten to maintain a target illumination level. This enhances visual comfort, reduces energy consumption, and ensures compliance with green building standards. Unlike analog photocells, they provide precise data and can be flexibly assigned to different lighting groups, making them ideal for offices, classrooms, atriums, and retail spaces.

Measure ambient lux levels.
Support daylight harvesting (dimming artificial lights when sunlight is available).
Enable constant light control to maintain target lux.

Use Cases: Open-plan offices, atriums, meeting rooms.

3. Push Buttons & Wall Switches (IEC 62386-302)

Pushbuttons & Switches, defined under IEC 62386-302, provide a simple yet powerful way for users to interact with a DALI lighting system. Unlike traditional wall switches, these digital devices communicate directly over the bus, sending event-based messages such as short press, long press, or double press to trigger actions like switching, dimming, or scene selection. Their functions can be reprogrammed via software, allowing the same button to serve different purposes in different spaces without rewiring. Available as single switches, multi-button panels, or rotary dimmers, DALI pushbuttons and switches are widely used in meeting rooms, classrooms, offices, and hospitality projects to combine intuitive manual control with the flexibility of advanced lighting automation.

Single or multi-button panels.
Short/long press for scene control.
Rotary dimmers for manual adjustment.

Use Cases: Meeting rooms, lecture halls, hospitality spaces.

4. Advanced Panels & Touch Controls

Touch Panels provide a modern, intuitive interface for lighting control, featuring capacitive touch or LCD displays. They connect directly to the DALI bus, sending digital commands for brightness, scenes, or zone management. Easily reprogrammable via software, they adapt to changing space requirements. Commonly used in conference rooms, retail, and hospitality, they combine style with flexibility.

Capacitive touch panels.
LCD wall panels with programmable scenes.
Mobile app interfaces via DALI gateways.

Advantages of DALI Input Devices

✅ Standardized Communication – Multi-vendor interoperability.
✅ Reprogrammable – Change function via software, no rewiring.
✅ Event-Driven Reporting – Efficient bus communication.
✅ Energy Efficiency – Automatic daylight & occupancy control.
✅ User-Friendly – Scene-setting, personalized control.
✅ Scalable – Works in small rooms or large campuses.

Applications

Offices – Occupancy + daylight sensors reduce energy use by 30–40%.
Universities – Lecture halls with scene-setting wall panels.
Hospitals – Daylight-balanced lighting for patient comfort.
Airports – Automated lighting in corridors, restrooms, terminals.
Retail & Hospitality – Scene-based controls for dynamic lighting.

Leading Brands & Products

Tridonic – DALI-2 sensors, SceneCOM controller.
Helvar – Imagine router + DALI multisensors.
Philips/Signify – OccuSwitch DALI-2 sensors.
B.E.G. Luxomat – Occupancy sensors for DALI-2.
Lunatone – DALI control modules and converters.
Steinel – High-performance PIR and microwave sensors.

Case Studies

1. Office Building in London

Integrated occupancy + daylight sensors.
Reduced lighting energy consumption by 38%.
Automated reports via DALI-2 controllers.

2. University Campus in Germany

DALI wall panels + multisensors in lecture halls.
Scene control for presentations, exams, lectures.
Improved student comfort and focus.

3. Hospital Project in UAE

Daylight harvesting in patient wards.
Tunable lighting adjusted by both lux sensors and nurse control panels.
20% energy savings + improved recovery environment.

Installation & Commissioning Best Practices

Position occupancy sensors for maximum coverage (avoid obstructions).
Calibrate daylight sensors at desk height for accuracy.
Use certified DALI-2 devices to ensure compatibility.
Test button panels for correct event mapping.
Document device addresses for future maintenance.

Challenges & Limitations

⚠️ Cost – Higher upfront than stand-alone sensors.
⚠️ Commissioning Required – Needs software setup.
⚠️ Bus Limitations – Max 64 devices per DALI line.
⚠️ Complexity – Training required for integrators.

Future Trends

Wireless DALI Input Devices – Bluetooth Mesh & Zigbee integration.
AI-Driven Sensors – Occupancy + people counting + heat mapping.
IoT Integration – Cloud-connected lux and occupancy data.
Smart Buildings & Digital Twins – Input device data used for predictive modeling.

Conclusion

DALI input devices (IEC 62386-301–304) are the essential link between users, the environment, and lighting systems. From occupancy and daylight sensors to push buttons and touch panels, they enable dynamic, energy-efficient, and user-friendly control.

With standardized communication, multi-vendor interoperability, and strong integration with building management systems, DALI-2 input devices are driving the next generation of intelligent lighting.

For integrators, consultants, and facility managers, investing in DALI input devices ensures compliance, scalability, and future-proof lighting control.