Interfaces

Interfaces are necessary for different components within a light management system to communicate. All relevant information is gathered and processed in the control device, and then transmitted to the components if necessary. Interfaces exist between the control device and

  • the sensors,

  • the operator, and

  • the luminaires’ control gear units.

The sensors of the lighting control capture movements or presence as well as light and convert the measured values into signals for transmission to the control device. The type of connection as well as the composition of signals, meaning the protocol, characterise the interface. This interface is usually system-specific in commercial sensor systems today. This means that sensors only fulfil their intended function when connected to the corresponding control device without necessitating adjustments outside of obligatory commissioning.

However, even when using commercially available, general-use interfaces for sensors or operating elements such as ZigBee or WLAN, the definition of interfaces in use regarding lighting is incomplete. The assignment of functions to commands, meaning the protocol, is only formally defined, but not specified in terms of content. The content definition is established by the provider of the functional overall system. Due to this, components of different light management systems are usually not mutually compatible despite using the same interface.

Lighting interfaces
For the communication between control device and luminaires or control gear units, there are commercially available interfaces which are more or less standardised regarding the effects of their functions on the lighting to be operated. They can be referred to as lighting interfaces.

The following passage is intended to describe and compare common commercially
available lighting interfaces.

In the following chapter, DALI, an internationally standardized lighting interface, is examined in more detail (see chapter 2.4.4.5). In a currently extended version of this interface (DALI-2), sensors and the operation devices are also standardized (see Figure).