Daylight Dimming

What you can build

• Lower the ceiling on a sunlit perimeter

  A south-facing zone's light sensor reads above target every clear afternoon while the group runs at its scheduled level. The operator proposes a lower afternoon ceiling for that zone, citing the readings and the sky cover behind them.

  With DALI Lighting, Weather & Severe Alerts

• Start the lights when people arrive

  The schedule brings a floor to full at six; the first badge-in lands closer to eight. The operator proposes a later start for that floor and shows the badge times it used.

  With DALI Lighting, Access Control

• Use the occupancy the BMS already holds

  Where the building platform carries occupancy per zone, the operator reads it over BACnet and proposes returning a zone to schedule once its override has outlived the last occupant.

  With BACnet / IP, DALI Lighting

• Catch a light sensor that has stopped reporting

  A sensor's illuminance has not moved for days while Open-Meteo's cloud cover has swung from clear to overcast. The operator proposes a sensor check for that zone instead of a schedule change.

  With DALI Lighting, Open-Meteo

Requirements

• A DALI-to-IP gateway with the group and scene map for the zones in scope, and DALI-2 light sensors on the bus
• An occupancy source: DALI-2 occupancy sensors, credential events from access control, or occupancy points on the BMS over BACnet
• A sky cover source: the NWS gridpoint forecast for a US site, or Open-Meteo elsewhere
• A target illuminance and dim bounds per zone, set by you, with emergency circuits excluded

Authentication

Uses the DALI gateway, access control, and building platform credentials you attach, plus the public weather feed. It holds no lighting credential of its own and writes nothing until a person approves.

Limits

• A DALI subnet holds 64 control gear and 64 control devices. Zones that span subnets are matched by the map you provide, not discovered
• It proposes schedule changes, not live dimming. Minute-to-minute daylight response stays with the application controller on the bus
• NWS sky cover is a forecast grid value, not a rooftop reading. Where sensor and forecast disagree, the sensor wins and the disagreement is noted
• Badge events show arrivals, not presence at a desk. Without occupancy sensors, a zone counts as occupied from first badge-in to last badge-out

Questions and answers

What does a person approve?

One zone at a time: the group, the current schedule level or time, the proposed one, the light sensor readings and sky cover behind it, and the occupancy it observed. The lead approves, edits the number, or declines. An approved change is sent to the gateway once.

What record does a change leave?

For each approved change: the zone, the level or time before and after, the readings cited, who approved it, when it took effect, and the prior schedule so it can be put back. Declined proposals are kept with the reason given.

Does it dim lights on its own?

No. It reads the bus and the weather and writes a proposal. Live dimming stays with the application controller and the sensors on the bus. A schedule changes only after a person approves it, and emergency circuits are never in scope.