According to a feature of the present invention, information regarding wakeup or shut-down may be conveyed from inverter 204 to converters 205. The information may be transmitted using any of the methods well known to those experienced in the art. According to certain embodiments, a modulation method may be used, by way of example, frequency modulation (FM) transmission, amplitude modulation (AM), FSK (frequency shift keying) modulation, PSK (phase shift keying) modulation, various QAM (Quadrature amplitude modulation) constellations, or any other method of modulation. Alternatively, inverter 204, while converting power from its input to its output, actively creates a frequency ripple in serial string 203. During normal operation, the 100 Hz (or 120 Hz in USA) ripple is detectable in serial string 203 since the capacitors of inverter 204 do not entirely block the alternating current (AC), and an additional signaling mechanism is not required to produce the 100/120 Hz signal in serial string 203. Alternatively or in addition, one or more switching frequencies of inverter 204, typically 16 Khz or 32 KHz may be detectable as leakage or provided intentionally to serial string 203.

Reference is now made to FIG. 2A which illustrates a feature of the present invention. In FIG. 2A, converter 205 is shown in more detail. Integrated with power converter 205 is a detector/receiver 207, according to a feature of the present invention which is configured to receive, optionally amplify and detect the signal, e.g. at 100/120 Hz originating in inverter 204.