In order for you to use Accumulated Light you must first have a Light sensor Installed on the controller

iGrow1400 Irrigation Accumulated Light Programming

To program simply hit Enter/Menu -> Program Equipment -> Hit Enter/Menu to highlight Output -> NEXT to scroll over to Equipment type field -> hit + till you display IRR then hit Back.  Hit NEXT to highlight the MODE -> hit + till you highlight Accum Light.

 Accumulated light mode allows you to turn the Irrigation channel ON for a duration equal to the OnTime

 

The irrigation valve will only turn on between the Start time and End time and will only do so when the appropriate amount of light has been accumulated.  Both of the start and end times can be astronomically adjusted to vary with respect to either sunrise or sunset.

 

Note: If the accumulation does not reach the threshold at the end of the time window the accumulation will still continue, however, if the threshold is reached outside the time window, irrigation will not take place until the beginning of the next active time window.

 

In the third screen you will need to set the accumulated light threshold.  You have the option of setting it as a function of the air temperature.  For example, you might have a threshold of 6000 w/m2-hr at a temperature of 70 ºF and a threshold of 5550 w/m2-hr at an air temperature of 80 ºF.  The threshold will then be a straight line interpolation between the two temperature thresholds.  Note:  If you don’t want it set as a function of temperature, then simply make the two accumulated light entries the same.

 

The last entry is the Max off time.  This is similar to a safety net.  In the event that the accumulated light is below the threshold when the maximum off time is reached, irrigation will take place anyway and the accumulator will be reset

Here is an example: