The light communication system is a unique, low-cost way to improve communication between truck drivers and your dock personnel. The simple red and green lights -- instantly understood as "stop" and "go" -- provide clear signals to dock workers inside and truck drivers outside. So your loading dock can operate more safely and efficiently.
Light communication systems can also help to ease the loading dock approach for truck drivers.
Guarding the Docking Process
Principally, dock protecting devices always have to prevent the truck driver from causing damage to the building or the vehicle. This can normally be guaranteed by the right choice of dock bumpers. However if this is not possible – e.g. with extremely low loading docks or when truck doors have to be opened after vehicles are parked at the loading dock - other solutions have to be found. Since hydraulic dock bumpers have not yet become widely accepted on the market, light communication systems are often used as an alternative.
One or more photoeyes detect the approaching vehicle and the light signal changes from green to red, or in case of two photoeyes, from green via yellow to red. This will allow the truck driver to stop systematically without using any mechanical dock protection (dock bumpers).
The departure of the vehicle can also be controlled by a light communication system. The dock attendant changes the light signal – which is automatically turned to red by the photoeyes when the truck backs in – to green by pushing a button, while the vehicle is still standing in the detecting zone of the photoeyes. Dock personnel are responsible for their own safety by giving the truck driver the green light signal for departure.
Safeguarding Unintended Departure
If the loading dock can be protected against damages of approaching vehicles by choosing the right dock bumper, the light communication system indicates the truck driver the current status of the loading operation.
The simplest and most favored solution is to control the light communication system by a pushbutton. Only the dock attendant is responsible for changing the outside light signal from green to red before the loading operation begins. After finishing the loading operation, he indicates the truck driver when to depart safely from the loading dock by changing the light signal from red to green.
A more effective and expensive alternative is to control the light communication system by the position of the dock leveller. The light signal can be controlled by a limit switch either at the telescopic lip assembly (normally at support legs) or at the mechanical rest position (hinge lip). The light flashes green when the dock leveller is in its resting position. As soon as the dock leveller is activated, the light signal switches from green to red. When the dock attendant returns the dock leveller to its rest position after the loading operation is completed, the light signal changes automatically from red to green. Dock personnel can not “forget“ or “bypass” this safety system. | 
Traffic light with warning signs (normal and mirror writing)
Control box with red and green communication lights |