Why smart lighting in industry
Classical industrial luminaires know two states: on and off. Networked luminaires additionally deliver dimmable brightness, colour-temperature control and — crucially — diagnostic data. The two dominant bus standards are IO-Link (in the machine context) and DALI-2 (in the building context).
Concrete benefits in machine engineering:
- Status feedback to the PLC — over-temperature, driver fault, luminous-flux degradation are reported by the luminaire controller itself.
- Predictive maintenance — remaining service life can be estimated from operating hours and driver temperature; maintenance becomes plannable.
- Recipe switching — brightness and colour temperature are set automatically when the workpiece or job changes.
IO-Link 1.1 — point-to-point bus for the machine
IO-Link per IEC 61131-9 is a cyclic point-to-point bus over an unshielded three-wire cable and standardised M12 connector. An IO-Link luminaire is a sensor / actuator like any other on the IO-Link master:
- Cycle time typically 0.4–10 ms, sufficient for lighting control
- Parametrisation via the IODD (IO Device Description) stored in the master
- Maximum cabling 20 m, independent of wire cross-section
- Diagnostic data over the service channel in parallel with process data transfer
Advantage in machine engineering: existing IO-Link infrastructure (sensors, actuators) is reused — no separate lighting cabling required.
DALI-2 — bus standard for networked lighting
DALI-2 (IEC 62386) is the established bus standard for building lighting and is increasingly used in industrial halls as well. Unlike IO-Link, DALI-2 addresses up to 64 nodes per bus segment in a free topology (line, star, tree) over a twisted-pair two-wire cable.
Strengths in industrial use:
- Scalability — a single line covers many luminaires, ideal for large halls
- Trade separation — machine control remains independent of the lighting bus
- Lighting management systems — daylight-linked dimming, presence detection, energy monitoring
The choice between IO-Link and DALI-2 depends on the application focus. Machine integration → IO-Link. Hall general lighting → DALI-2. In modern plants both standards are often used in parallel.