Emergency lighting system (1, 101), comprising an interface device (51, 151, 251) which is equipped with a radio module (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239), or comprising multiple interface devices (51, 151, 251) which are equipped with radio modules (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239), and comprising at least one first emergency light (19, 119) and comprising at least one second emergency light (21, 121), which are connected to one another via a radio channel, wherein data (177, 185, 187, DK1, DK2, DK2', DK3) can be transmitted on the radio channel by the second emergency light (21, 121), which is equipped with a radio module (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239), wherein data (179, 181, 183, 185, 187, 189, 191, DK2, DK2') regarding a state of the second emergency light (21, 121) can be forwarded by the first emergency light (19, 119), which is equipped with a radio module (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239), and wherein the interface device (51, 151, 251) by means of its radio module (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239) represents a radio node (P1, P2, P3) communicating (SK1, SK2, SK3) on the radio channel, and the interface device (51, 151, 251) has at least one contact (61, 63, 261, 263, 264, 265), characterized in that the at least one first emergency light (19, 119, 21, 121, 23, 123, 24, 124) and the at least one second emergency light (19, 119, 21, 121, 23, 123, 24, 124) and the interface device (51, 151, 251) can be brought into data exchange, by means of the at least one radio channel over which state data (177, 179, 181, 183, 185, 187, 189, 191) can be transmitted, with a further radio participant device (29, 33, 35, 36, 37, 38, 39, 134, 136, 137, 138, 139) of the emergency lighting system (1, 101), to which a communication path is not initially established, wherein the interface device (51, 151, 251) is equipped with an electronic part, having a timer or a timing element, for the connection of at least one building management system (57, 157, 59), and in that one contact (61, 63, 261, 263, 264, 265) of the at least one contact (61, 63, 261, 263, 264, 265) is an output contact (63, 263, 264) which, as a combined fault contact (269, 269'), designates a number of different faults for informing the building management system (57, 157, 59) about faults and which is switchable only when a fault exists for a minimum duration, and one contact (61, 63, 261, 263, 264, 265) of the at least one contact (61, 63, 261, 263, 264, 265) is an input contact (61, 261, 265) which is an galvanically decoupled voltage contact for a wide-range voltage or which serves to connect a remote radio module (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239) via connecting lines, and in that the radio module (33, 34, 134, 35, 36, 136, 37, 137, 38, 138, 39, 139, 239) of the interface device (51, 151, 251) comprises a microcontroller with a control program, so that, via the input contact (61, 261, 265), emergency lights (19, 119, 21, 121, 23, 123, 24, 124) of the emergency lighting system (1, 101) can be switched on by objects in a data tuple which are filled in by the microcontroller, the data tuple being communicated on the at least one radio channel.