In a method for gathering time-variable data from electronic slave devices in data communication through a data transmission channel with an electronic master device, the slave devices periodically measure and store a current value of at least one respective time-variable parameter (P1(t), . . . Pn(t)). The master device sends a freeze command to the slave devices. Upon receipt of the freeze command from the master device, the slave devices freeze the last measured value of the at least one time-variable parameter. During a data-gathering time interval following sending of the freeze command, the master device gathers the frozen values from the slave devices.