A method for communication between transceivers of module level devices, MLD, provided to monitor and/or to control associated photovoltaic modules, PVM, and a transceiver of a base station of an inverter having a transmitter (2-TX) and a receiver (2-RX), wherein the transceivers are coupled by associated duplexer circuits to a DC power network comprising power cables connecting the photovoltaic modules, PVM, of at least one photovoltaic string of a photovoltaic array with said inverter, wherein a signal amplitude of a communication signal, CS, transmitted by a transceiver via its associated duplexer circuit is adjusted automatically depending on a monitored impedance, Z PV, of said photovoltaic array, wherein the monitored impedance, Z PV, of the photovoltaic array is determined depending on a measured communication signal, CS, or a test signal received by the receiver (2-RX) of the transceiver of the base station of the inverter via its associated duplexer circuit and depending on a reference signal, RefSig, wherein the reference signal, RefSig, comprises a calibrated communication signal with a predetermined amplitude transmitted by the transmitter (2-TX) of the transceiver of the base station of the inverter via its associated duplexer circuit, wherein the signal amplitude of the communication signal, CS, transmitted by the transmitter (2-TX) of the transceiver of the base station during operation of the photovoltaic array is adjusted automatically depending on the determined impedance value, Z PV, of the photovoltaic array such that the amplitude of the communication signal, CS, is below a predetermined threshold value, characterized in that the monitored impedance value, Z PV, of the photovoltaic array is determined by calculating the impedance value, Z PV, depending on a turn ratio, N, and a coupling coefficient, K, of a transformer of the duplexer circuit coupling the transceiver of the base station of the inverter to the DC power network connecting the photovoltaic modules, PVM, in the respective photovoltaic string of the photovoltaic array and depending on a resistance, R, of a voltage divider resistor connected to a primary side of said transformer in response to the measured received communication or test signal and the reference signal, RefSig. wherein a signal amplitude of a communication signal, CS, transmitted by a transceiver via its associated duplexer circuit is adjusted automatically depending on a monitored impedance, Z PV, of said photovoltaic array, wherein the monitored impedance, Z PV, of the photovoltaic array is determined depending on a measured communication signal, CS, or a test signal received by the receiver (2-RX) of the transceiver of the base station of the inverter via its associated duplexer circuit and depending on a reference signal, RefSig, wherein the reference signal, RefSig, comprises a calibrated communication signal with a predetermined amplitude transmitted by the transmitter (2-TX) of the transceiver of the base station of the inverter via its associated duplexer circuit, wherein the signal amplitude of the communication signal, CS, transmitted by the transmitter (2-TX) of the transceiver of the base station during operation of the photovoltaic array is adjusted automatically depending on the determined impedance value, Z PV, of the photovoltaic array such that the amplitude of the communication signal, CS, is below a predetermined threshold value, characterized in that the monitored impedance value, Z PV, of the photovoltaic array is determined by calculating the impedance value, Z PV, depending on a turn ratio, N, and a coupling coefficient, K, of a transformer of the duplexer circuit coupling the transceiver of the base station of the inverter to the DC power network connecting the photovoltaic modules, PVM, in the respective photovoltaic string of the photovoltaic array and depending on a resistance, R, of a voltage divider resistor connected to a primary side of said transformer in response to the measured received communication or test signal and the reference signal, RefSig.