A monitoring system including a reading device electrically connected to a probe via a wired interface. The probe has a physiological sensor/transducer configured as a Wheatstone resistive bridge balancing circuit. Integrated within the housing of the probe to prohibit separation during use by a user is a memory device arranged in parallel with the sensor. Communication between the reading device and the probe occurs via a wired interface utilizing a same number of electrical wires between the reading device and the Wheatstone as would be required without the memory device. Control circuitry selects between one of two modes for accessing either data detected by the sensor or the memory device. Reading Device Probe z 130 4 wires Control vs+ Vs- Sensor/Transducer circuit Cnrland bridge ControloCircui Sensor+ balancing 115 circuit Siensor- (e.g. Wheatstone) 5135 Line 1 S 15SCILK ( ..) DIM ory Line k! Do Device. k wires Control Circuit 1/o -w wON/OFF One-wire sci 8W3a 250 master NO '255 VD AD Memory i235 VS+ Devi
