Install electronic labels on the shelf, in principle placing a product in the store (a label represents a product) and one order for a processing unit, the system causes the corresponding label to light up in the order, picking member according to the bright lights and digital display to take out the goods from the shelf. This is called pick to light according to the order.

Each label represents an order customer or a distribution object. Taking out the total quantity of the ordered goods first, and scanning the good's bar code to light up the according PTL label. The distributor can match the goods to the cargo space corresponding to the light or digital display of the PTL label. Put to light wall can be divided into fixed type or mobile type.