Daylight Harvesting

In part 304 installations, the DALI control system makes a decision on how much light to artificially add to the environment.  In applications for daylight harvesting, this is complicated, since as artificial light is added, the reported value is the sum of two variables that are not measurable individually, we need to avoid abrupt changes, and use the DALI fade rate features to invisibly adjust the light levels, faster when adding light, slower when removing it.

DALI Daylight sensors are spread thru the intended area, and the data reported is then processed to deliver the light needed.

In simpler systems, the system does not learn from prior decisions - each decision to add or remove light, is made based on the sensor data.   This results in the system constantly hunting up and down for the correct level.    When a cloud causes daylight to be reduced, the system needs to react without much notice.  

From a user level, if there are wall switches for the user to select the lighting options, our multibutton AL-WS-8B ( and the single button AL-WS-DALI-010v ) is a used to receive the user instructions.   In Daylight Harvesting part 304 applications - it is used to inform the software control system, what the occupant of the room wants.  They can select a light level for example, turn the lights on or off, and the DALI control system will have to make the decision on how which lights to set to what ARC level.

In a system with part 304 sensors - we insert feedback into the control system.  We change the concept of setting the LED drivers directly to an ARC level, and instead we used the wall switch device to instruct the software for the intended delivered light level, the software then needs to send the LED Drivers the command to slowly adjust the ARC Levels to deliver the FC needed.   The wall switch sets the initial level ( to insure operation if the control system is offline ) and then the controller fine tunes the lighting based on part 304 feedback.