A surgical system for selective connection to a robotic arm comprising: an instrument drive unit including a first actuator, a linkage member having opposing first and second portions, the first portion operatively coupled to the first actuator such that actuation of the first actuator moves the first portion in a first direction and the second portion in a second direction opposite of the first direction and a drive member operatively coupled to the second portion of the linkage member and a surgical instrument detachably coupled to the instrument drive unit, the surgical instrument including a driven member operatively associated with the drive member of the instrument drive unit, and an end effector operatively coupled with the driven member, wherein translation of the driven member effects a first function of the end effector.
