A two-wire active sensor interface circuit includes a constant current circuit adapted to be coupled to a two-wire active sensor for receipt of a sensor current signal indicating one of two sensor states. The constant current circuit provides a preselected constant current amount positioned between the two sensor states that vary the sensor current signal thereby generating a current level indicator signal. Additionally, the two-wire active sensor interface circuit includes a digital interface circuit operably coupled to the constant current circuit for receipt of the current level indicator signal and produces an interface output indicating which of the two sensor states is present.