The dimming protocol is chosen once, at the driver, and everything downstream inherits it. Change your mind after the fittings arrive and you are changing drivers, not settings.
Dimming is not a feature you add later. It lives in the driver, and the driver is inside the luminaire. So the protocol has to be settled at the point the fittings are ordered — which is usually well before anyone has thought about scenes.
Enlighten Pro supplies four, and the choice between them is almost entirely about how many fittings there are and how independently they need to behave.
| Protocol | Signal | Addresses fittings? | Extra wires |
|---|---|---|---|
| TRIAC | Mains phase-cut | No — a circuit dims together | None |
| 0-10V | Analogue DC | No — a circuit dims together | Two |
| DALI-2 | Digital, two-way | Yes — individually | Two |
| Wireless | RF mesh | Yes — individually | None |
Read that table as a cost gradient in both directions. TRIAC is cheapest to buy and cheapest to wire, and gives you the least control. DALI-2 costs more per driver and needs a pair of conductors everywhere, and gives you every fitting separately with feedback from each one.
Both of these are analogue, and both share one limitation that decides most projects: every fitting on the circuit receives the same signal and does the same thing. Zoning is done with wiring, not with software.
The dimmer cuts part of each mains half-cycle and the driver reads the remainder. Its whole appeal is that it needs no extra conductors — the existing switch drop becomes the dimmer. That makes it the right answer for a residential retrofit where pulling a control pair is not on the table.
What to watch: TRIAC is the least predictable of the four. Driver and dimmer have to be compatible, minimum-load rules apply, and flicker or a limited dimming range at the bottom of the curve is common when they are not matched. Test the actual pairing before committing a whole floor to it.
A separate low-voltage pair carries a simple analogue level. It is robust, cheap, easy to fault-find with a meter, and completely predictable. Two conductors go to every fitting; all fittings on that pair track together.
Polarity matters and is the usual site error. Beyond that there is very little to go wrong, which is exactly why it persists in industrial and warehouse work where nobody wants a commissioning stage.
Neither of these can tune colour. A single analogue level carries one instruction. Tunable white needs either two channels wired and dimmed separately, or a digital protocol that carries colour as its own value.
DALI is a digital, two-way, addressable bus defined by IEC 62386. Each piece of control gear gets a short address, and the controller talks to them individually, in groups, or all at once. It also asks — a DALI line can report a failed driver rather than waiting for someone to notice a dark fitting.
The figures that actually constrain a design:
| Limit | Figure | What it means on site |
|---|---|---|
| Control gear per line | 64 | Drivers, not luminaires — a head built with two modules eats two |
| Control devices per line | 64 | Sensors and panels, in their own address space. Counting them against the gear 64 is a DALI-1 rule |
| Bus current | 250mA | The ceiling from all supplies together. Many PSUs deliver 125–200mA |
| Bus voltage | 16V nominal | In-spec idle is 9.5–22.5V. A meter reading 14V or 20V is not a fault |
| Dimming range | 0.1–100% | IEC 62386-102's logarithmic curve, level 1 to level 254 |
DT6 is single-channel dimming. DT8 carries colour as well — tunable white or RGBW — as its own value on the same address. A DT8 head on a DT6-only controller dims perfectly and never tunes, which is a frustrating way to discover the difference at commissioning.
And a product sold as “tunable white” but built as two DT6 channels consumes two addresses per head, halving what a line can carry.
The DALI bus is not SELV. Inside control gear it is separated from the mains by basic insulation only, so the pair is treated as mains-voltage wiring — cable rated for the installation's mains voltage, double-insulated. That is what permits it to share a conduit with mains without segregation, and it is why isolating “the control circuit” is not enough: a fault in any one of up to 64 luminaires can put the pair at mains potential.
RF mesh control — Zigbee, Bluetooth mesh and the proprietary systems built on it — gives you addressability without pulling a control pair. On a retrofit, or anywhere a chase is not available, that is decisive.
What you trade for it:
Wireless earns its place in refurbishment, in heritage work where a chase is not permitted, and in fit-outs where zoning is expected to change. On a new-build with an accessible ceiling void it usually loses to DALI on lifetime maintainability, not on capability.
Four questions, in this order. The first one that gives a hard answer settles it.
Where Enlighten Pro stops. We supply the luminaire and its driver, wired to the protocol you specify, and the wiring guides that get the bus to it. The controller, the panels, the scenes and the commissioning belong to your automation contractor. Deciding that boundary early is as useful as deciding the protocol.
Most of these are repeated confidently on site. All five are wrong, and each has cost someone a day.
| The claim | What is actually true |
|---|---|
| “More than 64 devices kills the DALI line” | It does not. Short addresses are a 6-bit field; the commissioning tool assigns 64 and the surplus simply stay unaddressed |
| “A ring topology kills the line” | Sometimes it works and sometimes it does not. The near-universal ban is justified by fault-finding — a loop gives a fault two paths — not by a clause you can cite |
| “A second bus supply kills the line” | The real rule is that the total from all sources stays under 250mA. Surplus supplies are normally disabled by the commissioning tool |
| “The driver dims to 0.03%, it says so” | That is the driver's own analogue floor. Over standard DALI the curve bottoms out at 0.1%, and you will never reach the datasheet figure |
| “Swap the failed head and it comes back” | A replacement inherits nothing — not its address, groups, scenes or colour limits. Fitting it is an electrician's job; putting it back on the line is a commissioning one |
One diagnostic worth carrying: if every fitting on a line sits at full output and ignores the controller, the cause is almost always a short across the pair or no bus supply at all. A driver that hears nothing falls back to its system failure level, and the factory default for that is 254 — full.
The wiring itself is covered separately: the DALI hub has the three wiring cases, and CIANA 48V on DALI covers the magnetic track in detail.
Send the zoning intent and the fitting schedule — the protocol follows from those two, and it is easier to settle now than at commissioning.