Rope displacement sensors are particularly suitable for linear guide systems, hydraulic cylinder systems, testing machines, telescopic systems (forklifts, presses, elevators, pipe benders, bending machines, etc.), cranes or cable winches, reservoir dam protection systems, gate openings Degree control system, testing machine pressure machine, hydraulic universal experimental machine, storage location positioning, pressure machine, paper machine, textile machine, sheet metal machine, packaging machine, printing machine, level control instrument, construction machine, level control instrument, construction machinery , Industrial robots, injection machines, woodworking machinery, elevators, air compressors/hydraulic machines, height machines, XY axis and other length displacements and other related size measurement and position control, especially suitable for the control of electro-hydraulic servo hydraulic universal testing machines. It can completely replace the grating ruler, and can be customized for other applications, which can completely realize low-cost and high-precision measurement.