Cable system

A cable system comprising:

• a cable connecting a base device and a travelling body, functions of the cable at least including transmission of signals;
• a reel device disposed on the travelling body, the reel device having a reel onto which the cable is to be wound, a motor that drives the reel and a rotation sensor that detects a rotation of the reel;
• a motor controller that controls the motor of the reel device;
• and
• an acceleration sensor that is disposed in the traveling body and detects an acceleration in a vertical direction;
• the motor controller basically opening a motor drive circuit for driving the motor or bringing a supply current to the motor to zero when it is determined that the reel is rotated in an unreeling direction for unreeling the cable based on sensed information from the rotation sensor;
• the motor controller basically activating the motor to provide the reel with a rotary torque in a reeling direction when it is determined that the reel is rotated in a reeling direction for reeling the cable based on the sensed information from the rotation sensor;
• and
• the motor controller activating the motor to provide the reel with the rotary torque in the reeling direction if a differential value of the acceleration sensor is greater than a reference value even when the reel is rotated in the unreeling direction.