V5−T is a special inverter with high-performance vector control on Tension Control. It devotes to controlling speed with roll diameter calculation and tension matched with pendulum but no encoder. V6−T is a special inverter with high-performance torque control and vector control on Tension Control. It devotes to controlling speed with an encoder, roll diameter calculation and tension pendulum and also or not. With the requirements met on rewinding and unwinding machine, it not only achieves requirements of cost saving, improvement on product quality and production efficiency,but also easy maintenance and easy debugging.