Luminaire arrangement having a ballast and at least one luminaire connected to the ballast via a cable, in which - the ballast has at least two terminals for providing an operating voltage for the luminaire with alternating voltage potential at the two terminals so that a current flows with alternating polarity, a terminal for a protection potential, and a terminal for an ignition pulse, - the luminaire has a luminaire housing, a luminous means and an ignition circuit, and at least two terminals connected to the illuminant for the supply of the operating voltage, a protective terminal connected to the lamp housing, and a terminal connected to the ignition circuit, - the cable connects the ballast to the luminaire with at least one number of conductors corresponding to the number of connections, characterised in that the luminaire has a microcomputer and at least one sensor connected to the microcomputer and the ballast has a microcomputer, the microcomputer of the luminaire being set up for the intermediate storage of data of the at least one sensor connected to it and for the transmission of the data to the ballast after a corresponding request by the ballast, and in that a bidirectional digital data exchange is provided between the microcomputers (18, 20) respectively by a data transmission circuit connected to two further terminals of the luminaire and a data reception circuit connected to two further terminals of the ballast in the ballast and in the luminaire via additional conductors of the cable, and in that the data transmission circuits are designed as a current source with a high internal resistance and the data reception circuits are designed with a low internal resistance and with low passes. - the ballast has at least two terminals for providing an operating voltage for the luminaire with alternating voltage potential at the two terminals so that a current flows with alternating polarity, a terminal for a protection potential, and a terminal for an ignition pulse, two terminals for providing an operating voltage for the luminaire with alternating voltage potential at the two terminals so that a current flows with alternating polarity, a terminal for a protection potential, and a terminal for an ignition pulse, - the luminaire has a luminaire housing, a luminous means and an ignition circuit, and at least two terminals connected to the illuminant for the supply of the operating voltage, a protective terminal connected to the lamp housing, and a terminal connected to the ignition circuit, two terminals connected to the illuminant for the supply of the operating voltage, a protective terminal connected to the lamp housing, and a terminal connected to the ignition circuit, - the cable connects the ballast to the luminaire with at least one number of conductors corresponding to the number of connections, characterised in that the luminaire has a microcomputer and at least one sensor connected to the microcomputer and the ballast has a microcomputer, the microcomputer of the luminaire being set up for the intermediate storage of data of the at least one sensor connected to it and for the transmission of the data to the ballast after a corresponding request by the ballast, and in that a bidirectional digital data exchange is provided between the microcomputers (18, 20) respectively by a data transmission circuit connected to two further terminals of the luminaire and a data reception circuit connected to two further terminals of the ballast in the ballast and in the luminaire via additional conductors of the cable, and in that the data transmission circuits are designed as a current source with a high internal resistance and the data reception circuits are designed with a low internal resistance and with low passes. characterised in that the luminaire has a microcomputer and at least one sensor connected to the microcomputer and the ballast has a microcomputer, the microcomputer of the luminaire being set up for the intermediate storage of data of the at least one sensor connected to it and for the transmission of the data to the ballast after a corresponding request by the ballast, and in that a bidirectional digital data exchange is provided between the microcomputers (18, 20) respectively by a data transmission circuit connected to two further terminals of the luminaire and a data reception circuit connected to two further terminals of the ballast in the ballast and in the luminaire via additional conductors of the cable, and in that the data transmission circuits are designed as a current source with a high internal resistance and the data reception circuits are designed with a low internal resistance and with low passes.