A controller for positioning on a shelf of a cabinet within a mass storage system for controlling communication among device enclosures in a reporting group. The magneto-resistive resistance associated with a pair of readwrite heads oriented to read and write opposite recording surfaces of the storage medium. In the second stage, we developed a modified version of automatic off-resonance correction with a frequency constraint from the first stage map. With a wideband amplitude match and 180\xb0 out of phase, the performance of the transceiver is improved by the present invention for a few wide applications. Related methods may be used to adjust the duty cycle based upon a detected characteristic such as light, sound, motion or time.