The present invention is generally directed to a system and method for communicating between a personal data access device and a remote communication unit. The method includes detecting at least one of a power supply failure and a unit failure, monitoring the detected unit failures, and determining a detected unit failure for a first unit is erroneous if the monitoring indicates another of the units receiving power from a same power supply system as the first unit has also detected a unit failure. The pole sub-assembly and the units define front and rear fluid chambers containing a magneto-rheological fluid. Circuit breakers including the circuit breaker tripping mechanism and methods of tripping a circuit breaker are provided, as are other aspects. Knowledge of the patient’s nucleotide sequence in the Wiskott-Aldrich Syndrome Protein gene allows diagnosis of the patient’s primary immunodeficiency.