If the cable drag chain cable is stretched by tension during wiring, it will friction with the inner wall of the drag chain and cause the sheath to wear. On the contrary, if the wiring is too loose, it will also cause friction with the inner wall of the drag chain, causing the sheath to wear, and it will easily be entangled with other cables. The wiring length of the drag chain cable should be set to just pass the center line of the drag chain. In addition, if the moving part of the drag chain cable is fixed, the bending stress will not be dispersed and absorbed. The fixed part of the cable should be set at both ends of the drag chain.