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.