Two Protocols, Two Different Jobs
Dimming is one of the most consequential decisions in an LED installation. It sets energy use, shapes how long luminaires last, and determines whether a building or a road network can be managed centrally at all. The two methods most buyers encounter are DALI and PWM, and choosing between them is less about which is better than about what the project needs to do.
DALI, the Digital Addressable Lighting Interface, is a two-way digital protocol written specifically for lighting. Each driver carries an address, so a single pair of wires can control individual fixtures, groups, and scenes, and the driver reports status back. PWM, pulse width modulation, varies the duty cycle of the current to the LED, which is simple, cheap, and effective where control requirements are modest.
Matching the Protocol to the Application
Where individual addressing and fault reporting matter, DALI wins. In an office or a retail fit-out, the ability to reprogram scenes without rewiring and to read driver status from a dashboard is worth the additional cost, and DALI-2 certification has largely resolved the old interoperability complaints.
For infrastructure, the calculation differs. A Smart outdoor light network covering thousands of columns rarely needs per-luminaire scenes, but it does need reliable group control and fault reporting over long cable runs, which favours DALI at the distribution board or a dedicated outdoor control protocol rather than PWM.
In harsh interiors, simplicity often wins. A LED triproof lamp in a plant room or a cold store needs to dim reliably and survive washdown; PWM keeps the electronics simple and the sealed housing intact. For a led tunnel light, stepped control tied to external luminance sensors is usually specified, with the protocol chosen to match the operator's existing tunnel supervision system.
Luxsky Product Perspective
We specify drivers by application rather than by habit. Our industrial and outdoor families offer DALI-2 and 0-10V options alongside PWM, with the dimming curve, minimum dim level, and flicker performance documented for each so the commissioning engineer knows what the fixture will actually do.
Flicker is the variable most often overlooked when a protocol is chosen. At low dim levels, a PWM driver that performs acceptably at full output can produce visible flicker, which matters in any space with rotating machinery or moving vehicles. Asking for a measured percent-flicker figure at the minimum dim level prevents a complaint that no protocol change will fix afterwards.
Tell us the control system you intend to use and the environment the fixtures will live in. We will confirm which driver variant matches, and flag any case where the cheaper protocol would cost more over the life of the installation.
