Patent ID: 7623413

Claim:
A system for determining a distance for building automation components, the system comprising: a first building automation device having a first wireless transmitter, a first wireless receiver and a first processor; a second building automation device having a second wireless transmitter, a second wireless receiver and a second processor; wherein the first wireless transmitter is operable to transmit a first signal, the second wireless receiver is operable to receive the first signal, the second wireless transmitter is operable to transmit a second signal in response to detection of a first zero point crossing within the first signal and after an interval, the first wireless receiver operable to receive the second signal and detect a second zero point crossing within the second signal, and the first processor, second processor or a third processor operable to determine a distance between the first and second building automation devices as a function of the time between the detection of the first zero point crossing within the first signal and the detection of the second zero point crossing within the second signal.