The invention relates to rotator (10) for a jib-carried tool, said rotator comprising a stator (20) and a rotor (30) and a device (40, 50) for determining an absolute position of rotation between the stator (20) and the rotor (30). Said device (40, 50) comprises an encoder (40) surrounding the rotor (30 30) and a sensor (50). The encoder (40) is arranged rotationally fixed relative to the stator (20) and the sensor (50) is arranged rotationally fixed relative to the rotor (30), or vice versa. Said sensor (50) is arranged to determine the absolute position of rotation between the stator (20) and the rotor (30).