An apparatus for the control of endoscopic instruments includes a control module (16) mountable to a standard instrument port (32) of an endoscope (12). The control module includes separate drive mechanisms (60,64) for a sheath (46) and a tensile cord (48) of an endoscopic tool having an end effector (38). Driving the sheath and the tensile cord together may serve to advance or withdraw the end effector, driving either component separately may cause an activation of the end effector.
