A computer-assisted device comprising: a drive unit (2130, 2810) comprising a first actuator (2152, 2812) and a second actuator (2162, 2830); a first engagement member (2158, 2870) drivably coupled to the first actuator (2152, 2812); a second engagement member (2168, 2880) drivably coupled to the second actuator (2162, 2830); and a control unit coupled to the drive unit (2130, 2810); wherein the control unit is configured to, in an engagement mode: actuate the first actuator (2152, 2812) to drive the first engagement member (2158, 2870); detect engagement of the first engagement member (2158, 2870) with a third engagement member of an instrument, where a movement of the third engagement member causes a movement of an end effector of the instrument in a first direction of a degree of freedom; actuate the second actuator (2162, 2830) to drive the second engagement member (2168, 2880); and detect engagement of the second engagement member (2168, 2880) with a fourth engagement member of the instrument, where a movement of the fourth engagement member causes a movement of the end effector in a second direction of the degree of freedom, the second direction being opposite the first direction; characterized in that the control unit is further configured to: servo the first actuator (2152, 2812) to a constant commanded position after the detection of the engagement of the first engagement member (2158, 2870) with the third engagement member and before detection of the engagement of the second engagement member (2168, 2880) with the fourth engagement member; or continue actuation of the first actuator (2152, 2812) after the detection of the engagement of the first engagement member (2158, 2870) with the third engagement member and before detection of the engagement of the second engagement member (2168, 2880) with the fourth engagement member. a drive unit (2130, 2810) comprising a first actuator (2152, 2812) and a second actuator (2162, 2830); a first engagement member (2158, 2870) drivably coupled to the first actuator (2152, 2812); a second engagement member (2168, 2880) drivably coupled to the second actuator (2162, 2830); and a control unit coupled to the drive unit (2130, 2810); wherein the control unit is configured to, in an engagement mode: actuate the first actuator (2152, 2812) to drive the first engagement member (2158, 2870); detect engagement of the first engagement member (2158, 2870) with a third engagement member of an instrument, where a movement of the third engagement member causes a movement of an end effector of the instrument in a first direction of a degree of freedom; actuate the second actuator (2162, 2830) to drive the second engagement member (2168, 2880); and detect engagement of the second engagement member (2168, 2880) with a fourth engagement member of the instrument, where a movement of the fourth engagement member causes a movement of the end effector in a second direction of the degree of freedom, the second direction being opposite the first direction; actuate the first actuator (2152, 2812) to drive the first engagement member (2158, 2870); detect engagement of the first engagement member (2158, 2870) with a third engagement member of an instrument, where a movement of the third engagement member causes a movement of an end effector of the instrument in a first direction of a degree of freedom; actuate the second actuator (2162, 2830) to drive the second engagement member (2168, 2880); and detect engagement of the second engagement member (2168, 2880) with a fourth engagement member of the instrument, where a movement of the fourth engagement member causes a movement of the end effector in a second direction of the degree of freedom, the second direction being opposite the first direction; characterized in that the control unit is further configured to: servo the first actuator (2152, 2812) to a constant commanded position after the detection of the engagement of the first engagement member (2158, 2870) with the third engagement member and before detection of the engagement of the second engagement member (2168, 2880) with the fourth engagement member; or continue actuation of the first actuator (2152, 2812) after the detection of the engagement of the first engagement member (2158, 2870) with the third engagement member and before detection of the engagement of the second engagement member (2168, 2880) with the fourth engagement member. servo the first actuator (2152, 2812) to a constant commanded position after the detection of the engagement of the first engagement member (2158, 2870) with the third engagement member and before detection of the engagement of the second engagement member (2168, 2880) with the fourth engagement member; or continue actuation of the first actuator (2152, 2812) after the detection of the engagement of the first engagement member (2158, 2870) with the third engagement member and before detection of the engagement of the second engagement member (2168, 2880) with the fourth engagement member.