What does a sensor do on a Pick-to-Light compartment display?

A sensor on a Pick-to-Light compartment display is used to automatically acknowledge the removal of individual parts and also monitors access to the storage compartments. If the picker reaches into an incorrect compartment, the system automatically signals the incorrect access and ensures the quality of the removal.

Range from one Pick-to-Light sensor

Through a small red disc the transmitter emits its signals and receives the reflections back. The range, without additional reflection surface, is 15-20cm. In the range must be access to the storage compartment. For this reason, there are different designs in the installation.

The executions

The Pick-to-Light sensor must be connected to the electronics of the storage compartment display. There are various possibilities for its installation. Depending on the design, the modules are then installed above or below the storage compartments.

The classic: Pick-to-Light sensor below a compartment display

In the application, the compartment indicator is placed above the storage compartment. The access sensor monitors access to the compartment below. Advantage: The hand of the picker is clearly detected from a short distance during access.

Above the compartment display

If the containers are very flat or have a side access opening, the Pick-to-Light indicator can also be installed below the storage compartment with an access sensor facing upwards. This is also the natural way to install the compartment indicator (instead of the storage compartment labels).

Which version is better?

Both designs are good, and the choice depends on the dimensions of the containers and storage compartments. However, a uniform method must always be used here. The compartment displays should always be installed above or below. Mixed operation is not expedient for the orientation of employees.

The mode of operation

The main function of the Pick-to-Light sensor is a registration of accesses to a storage compartment. Depending on the state of the compartment display, different functions are possible:

  • With withdrawal quantity = 1: The sensor automatically acknowledges the withdrawal.
  • With withdrawal quantity > 1: The sensor only releases the acknowledgement key, but does not automatically acknowledge the withdrawal.
  • The display does not light up: An access error is signaled (light signal or horn).

There are many scenarios for how the functions are executed. We will be happy to advise you personally on this.


A Pick-to-Light sensor can be used very well for the removal of individual articles with the number of pieces = 1. The removal is automatically acknowledged and reported back. Access to the wrong storage compartments is automatically registered and an alarm can be triggered (optically or acoustically).


What is a Pick to Light sensor?

An access sensor on the Pick-to-Light compartment display is an electronic circuit with a component (transmitter diode) that emits a light signal and receives the reflection back from an object (receiver diode). By interrupting the light signal or receiving the distance modulation, access to a storage compartment can be determined automatically.

Can a Pick-to-Light sensor count the number of pieces?

No. A Pick-to-Light sensor only monitors access to a storage compartment, but cannot record the number of items removed. Counting scales are used for this purpose (see Pick-by-Weight).

What does a Pick-to-Light sensor cost?

An access sensor is always an option to a Pick-to-Light compartment display and costs approx. 60,-€ extra per storage compartment.

When is it worthwhile to use a Pick-to-Light sensor?

Especially for fast picking with the number = 1 piece. Here, the removal is immediately acknowledged with the sensor and automatically reported back to the warehouse management system.

Many years of experience in paperless order picking


WordPress Cookie Plugin by Real Cookie Banner