The function of circular loom series is mainly to achieve synchronization between rollers, uniform control of winding and unwinding. Its working principle can be divided into open-loop, closed-loop or free-loop control system according to the loop; According to the monitoring methods of different coils, it can be divided into ultrasonic type, floating roller type, tracking arm type and other control systems. The whole system is mainly composed of controller, detector, brake and clutch. The system is divided into direct control and indirect control. The control methods include manual control, semi-automatic mode, fully automatic and other methods.