An instrument drive connector for interconnecting an instrument drive unit and an end effector, wherein the instrument drive connector transmits at least one force from the instrument drive unit to the end effector to effect a function of the end effector, the instrument drive connector comprising: a housing assembly; an elongated shaft extending distally from the housing assembly; and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft, the first drive assembly including: a first drive screw having a proximal end and a distal end; a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw; a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto in response to rotation of the first drive screw; and a locking link including an elongated body having a proximal end portion and a distal end portion, the proximal end portion coupled to the first drive nut and longitudinally movable relative thereto between a proximal non-locking position and a distal locking position, and the distal end portion including a switch actuation assembly including a switch actuating arm biased towards the distal locking position; wherein the proximal end portion of the locking link includes a longitudinal slot formed therein, and the first drive nut has a rod disposed within the longitudinal slot of the locking link such that when the first drive nut is in the distal locking position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot, and when the first drive nut is in the proximal non-locking position, the rod of the first drive nut is disposed adjacent a proximal end surface of the longitudinal slot. a housing assembly; an elongated shaft extending distally from the housing assembly; and a first drive assembly at least partially disposed within the housing assembly and the elongated shaft, the first drive assembly including: a first drive screw having a proximal end and a distal end; a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw; a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto in response to rotation of the first drive screw; and a locking link including an elongated body having a proximal end portion and a distal end portion, the proximal end portion coupled to the first drive nut and longitudinally movable relative thereto between a proximal non-locking position and a distal locking position, and the distal end portion including a switch actuation assembly including a switch actuating arm biased towards the distal locking position; wherein the proximal end portion of the locking link includes a longitudinal slot formed therein, and the first drive nut has a rod disposed within the longitudinal slot of the locking link such that when the first drive nut is in the distal locking position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot, and when the first drive nut is in the proximal non-locking position, the rod of the first drive nut is disposed adjacent a proximal end surface of the longitudinal slot. a first drive screw having a proximal end and a distal end; a first input drive coupler non-rotatably coupled to the proximal end of the first drive screw; a first drive nut threadedly engaged with a threaded body portion of the first drive screw and longitudinally movable relative thereto in response to rotation of the first drive screw; and a locking link including an elongated body having a proximal end portion and a distal end portion, the proximal end portion coupled to the first drive nut and longitudinally movable relative thereto between a proximal non-locking position and a distal locking position, and the distal end portion including a switch actuation assembly including a switch actuating arm biased towards the distal locking position; wherein the proximal end portion of the locking link includes a longitudinal slot formed therein, and the first drive nut has a rod disposed within the longitudinal slot of the locking link such that when the first drive nut is in the distal locking position, the rod of the first drive nut is engaged with a distal end surface of the longitudinal slot, and when the first drive nut is in the proximal non-locking position, the rod of the first drive nut is disposed adjacent a proximal end surface of the longitudinal slot.