A surgical system for selective connection to a robotic arm includes an instrument drive unit and a surgical instrument detachably coupled to the instrument drive unit. The instrument drive unit includes a first actuator, a linkage member having opposing first and second portions, and a drive member. The first portion of the linkage member is 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. The drive member is operatively coupled to the second portion of the linkage member. The surgical instrument includes 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.