In various embodiments, a surgical tool for use with a robotic system is disclosed. The surgical tool comprises a housing, a shaft, an end effector, a motor configured to generate at least one rotational motion, a modular adapter, a motion conversion assembly, and a lockout sensor. The end effector comprises a circular stapler. The modular adapter is coupled to the housing and the robotic system and comprises at least three rotary shaft interfaces configured to actuate a closing motion and a firing motion of the circular stapler. The motion conversion assembly is operably coupled to the motor and the circular stapler. The motion conversion assembly is configured to convert the at least one rotational motion to at least one axial motion. The lockout sensor is operable to lockout the firing motion when the lockout sensor senses a spent condition of an interchangeable staple cartridge supported by the circular stapler.