The VESDA Laser Scanner (VLS) is similar to the VESDA Laser Plus (VLP), with the addition of an inlet manifold valve mechanism and software to control airflow from four separate sectors (pipes).

This configuration enables a single zone to be divided into four sectors, for example, distinguishing between separate spaces within a room.

In normal operation, the VLS draws air from all sectors in use. If the smoke level reaches a pre-determined threshold, the VLS identifies which sectors have smoke. The VLS then designates the first alarm sector. (If multiple sectors have smoke, the sector with the highest smoke concentration is designated as the first alarm sector, FAS.)

Once the FAS has been identified, the VLS continues to monitor all four sectors (pipes) to monitor fire growth.

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