Many other DALI functions are also defined. Commercially available DALI control devices are often designed for certain applications and only access a portion of defined DALI functions. Construction and operation of DALI control devices, design of operating panels used (push-button, touch panel etc.) as well as the range of supported functions are not defined in the DALI standard. DALI control gear units, however, are universally usable – meaning compatible with any DALI control device – if they feature the DALI logo (see section “DALI parameters and initialisation” at the end of chapter ). For colour control applications, other aspects may require consideration. In some cases, so-called DT8 control gear units can be used (see chapter ). There is a distinction between two communication principles:DALI broadcast mode (direct DALI) – all participants collectively follow one control signal. DALI addressing mode – every participant receives an individual address that facilitates individual operation, with the number of possible addresses being limited to 64. The DALI interface thus serves communication between one control device (master) and several control gear units to be controlled (slaves). This basic function, in contrast to the aforementioned interfaces, is optimised for functional lighting applications through a detailed definition of the standard. The DALI-2 interface offers fundamentally expanded functionalities on top, such as:parallel operation of several control devices (multi master operation), and connection and operation of standardised light sensors, standardised presence sensors and standardised push-buttonsat one joint control line with the control gear units. These functions have proven to be expedient supplements regarding frequently occurring lighting tasks.
