Abstract: This paper introduces the coordinated control of a frequency converter, sensor, and stepper motor using an S7-200 PLC in a cable winding machine, thereby achieving closed-loop speed control of the active drum and closed-loop tension control of the passive drum. The system not only achieves active constant-speed cable winding, but its key feature is the realization of constant-tension cable unwinding, effectively solving the problem of unifying the winding and unwinding processes. Experiments demonstrate the system's significant application value. Keywords: PLC, frequency converter, closed-loop control, constant tension, TD200 Aircraft dipping sonar is a detection device used by aircraft to detect enemy submarines, torpedoes, and other underwater weapons. During detection operations, the sonar detector needs to be lowered into the water using a dipping cable via a hydraulic winch, and continuously moved with the aircraft according to detection needs. This process causes significant damage to the dipping cable. Therefore, the dipping cable needs to be inspected and replaced after a period of use. Traditional cable replacement methods have significant drawbacks: First, manual replacement is slow, with uneven winding speed and force, leading to loose winding and uneven cable arrangement, requiring repeated operations. Second, while hydraulic winches mitigate some of the drawbacks of manual operation, their complex structure, low reliability, difficult maintenance, complex control mechanisms, and high hydraulic pressure make them prone to oil leaks. Third, microcontroller-based frequency conversion speed control cable arrangement has a long system development cycle, requires skilled operators, is inconvenient to maintain, and is unsuitable for harsh working environments. The development of the cable winding machine aims to solve these problems. Currently, most cable winding devices on the market are single-function, for example, only capable of constant-speed winding. Such winding devices require a lot of auxiliary work to complete their operation. The cable winding machine design solves these problems. This cable winding machine primarily utilizes a Programmable Logic Controller (PLC) as its automatic control system. This system not only achieves constant-speed cable take-up from the active winding drum but also constant-tension cable release from the passive winding drum, effectively solving the problem of unifying the cable take-up and release processes. [b]1 PLC Composition and System Working Principle 1.1 Introduction to PLC Composition[/b] [b][align=center]For detailed information, please click: Automatic Control System for Cable Wrapping Machine Based on PLC[/align][/b]