An instrument including working arms and a moveable member. The working arms include a first arm, a second arm, a first electrode located on the first arm, and a second electrode located on the second arm. The moveable member includes a passive circuit element, a first terminal, and a second terminal. The moveable member is moveable to a first position and a second position. In the first position, the first terminal is in electrical communication with the first electrode and the second terminal is in electrical communication with the second electrode so that in the first position an electrical circuit is completed. An impedance is measured of the passive circuit element in the completed electrical circuit. The instrument is adapted to provide a modality based on the measured impedance or a determined position of the moveable member.
