An invasive instrument (1) is disclosed comprising an instrument tip including a sensor chip (10) comprising a sensor (20) adapted to produce a modulated sensor signal having a signal frequency and a non-volatile memory (30) responsive to said sensor signal for storing data relating to said sensor； a first supply wire (11) for connecting the sensor chip to ground and a second supply wire (13) for connecting the sensor chip to a power supply (61) for providing a supply voltage to the sensor chip. The device further comprises a circuitry arrangement arranged to combine said sensor signal and said output into a combined signal and superimpose said combined signal as a modulation over the supply voltage such that simultaneous data communication of the sensor and memory data can be provided using two interface wires only. A system including such an invasive instrument and a method of operating such a system are also disclosed.
