A method for data communication between a transmitter/receiver module and an LED module comprising at least one LED or between a transmitter/receiver module and LED modules (M1, M2, Mn) in a series connection of several LED modules (M1, M2, Mn) each comprising at least one LED, each LED module (M, M1, M2, Mn) being supplied with current from a common controlled current regulator via a current supply line, wherein data is modulated onto the current supply line by means of an integrated circuit integrated into each LED module (M, M1, M2, Mn) for data communication from the respective LED module (M, M1, M2, Mn) to a modem arranged downstream of the current regulator and connected to the transmitter/receiver module, the data then being demodulated by the modem, wherein for data communication from the modem to the respective LED module (M, M1, M2, Mn) data is modulated onto the current supply line and demodulated by the integrated circuit, wherein the data from each LED module (M, M1, M2, Mn) to the modem is modulated onto the current supply line by means of changing the voltage drop across the LED module (M, M1, M2, Mn), and wherein the data to be transmitted from the modem to the respective LED module (M, M1, M2, Mn) is modulated by means of ASK (amplitude shift keying), wherein for the purpose of modulation, the current flowing from the current regulator via the current supply line to the respective LED module (M, M1, M2, Mn) is modulated with a modulation depth of m=1, wherein the data to be transmitted is Manchester-coded and wherein during data transmission the voltage drop across one LED of the LED module (M, M1, M2, Mn) is passed onto the integrated circuit which directly receives the transmitted data, wherein each LED module (M, M1, M2, Mn) is unequivocally addressed, characterised in that the method comprises the following steps: linearly increasing the nominal current of at least one LED module (M, M1, M2, Mn) during data transmission from the modem to the at least one LED module (M, M1, M2, Mn) in order to compensate for a drop in light output during this time, supplying each integrated circuit integrated into each LED module (M, M1, M2, Mn) with current through energy harvesting by means of a solar cell, a photo diode or a Seebek (Peltier) element, triggering an algorithm for failure detection by means of a broadcast command from the modem and starting a timer immediately upon triggering the algorithm for failure detection for a pre-set period of time in each LED module (M, M1, M2, Mn), wherein the pre-set period of time depends on an address of the respective LED module (M, M1, M2, Mn) and is thus unequivocal, wherein when the timer expires, the respective LED module (M, M1, M2, Mn) transmits data on the status of the LED module (M, M1, M2, Mn) to the modem, and wherein at the point in time that the timer expires, no data is received during an associated receive time slot of the algorithm on the status of the LED module (M, M1, M2, Mn), a failure or absence of the LED module (M, M1, M2, Mn) is detected. linearly increasing the nominal current of at least one LED module (M, M1, M2, Mn) during data transmission from the modem to the at least one LED module (M, M1, M2, Mn) in order to compensate for a drop in light output during this time, supplying each integrated circuit integrated into each LED module (M, M1, M2, Mn) with current through energy harvesting by means of a solar cell, a photo diode or a Seebek (Peltier) element, triggering an algorithm for failure detection by means of a broadcast command from the modem and starting a timer immediately upon triggering the algorithm for failure detection for a pre-set period of time in each LED module (M, M1, M2, Mn), wherein the pre-set period of time depends on an address of the respective LED module (M, M1, M2, Mn) and is thus unequivocal, wherein when the timer expires, the respective LED module (M, M1, M2, Mn) transmits data on the status of the LED module (M, M1, M2, Mn) to the modem, and wherein at the point in time that the timer expires, no data is received during an associated receive time slot of the algorithm on the status of the LED module (M, M1, M2, Mn), a failure or absence of the LED module (M, M1, M2, Mn) is detected.