Irrigation Programming - Accumulated Light Irrigation

In this mode the irrigation cycle is triggered when the accumulated light or “light sum” reaches a threshold or when the maximum off time limit is reached.

This mode gives the system the ability to water on a demand based usage to match the plants watering needs to the plant stress levels as induced by light intensity and temperature.

The Pearl will start to accumulate the light level (in Moles/meter2) until it reaches the desired threshold. Once reached, the valve will be opened by the amount set in the On Time parameter. However, as a precautionary measure, the valve is only allowed to be opened between the Start time and the End time. The light integration (or accumulation) continues to happen outside of this time. Should the threshold is reached outside of the indicated time period, the system will delay the valve activation until the allowable time window is met again.

Because the plants typically stress differently at different inside temperatures, the Pearl supports 2 different thresholds at 2 different temperatures. Typically, the lower temperature is associated with the higher light accumulation threshold. The higher temperature is associated with a lower accumulated light level. For temperature in between the 2 levels, a linear interpolation is used. Note: If you don’t want it set as a function of temperature, then simply make the two accumulated light entries the same.

The “ Maximum Off Time ” is intended as 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 at that time or, if the system is outside of the allowable window, it will water at the Start time. Then the light accumulator will be reset as well as the off timer.

To program Accumulated Light Irrigation from Pearl Cloud Platform you would do the following:

To program Accumulated Light Irrigation from Pearl Controller you would do the following:

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