Patent ID: 8497700

Claim:
A method comprising: superimposing a first carrier waveform upon a first logic level of a first digital signal, the first digital signal using a first local ground as a reference level; superimposing a second carrier waveform upon a second logic level of the first digital signal; propagating the first digital signal comprising the superimposed first carrier waveform, through an isolation barrier; and processing the propagated digital signal using a second local ground that is different than the first local ground, the processing comprising: using the first carrier waveform to enforce the first logic level upon an output digital signal generated from the propagated digital signal, the enforcing comprising: detecting the first carrier waveform in the propagated digital signal; and setting the output digital signal to the first logic level upon detecting the first carrier waveform in the propagated digital signal; and using the second carrier waveform to enforce the second logic level upon the output digital signal generated from the propagated digital signal.