1. Display Load moment indicator(also called as"crane computer" or "safe load indicator") can be in form of LCD dynamic graphics and comprehensive display the various parameters in the process of work. As the main hook load, auxiliary hook load,boom Angle, length, working radius, etc.; Alarm function Sound and light alarm function: when the crane boom work amplitude limit close to work, when lifting load and torque device close to the permitted load limit, torque system issued a warning of slow beeping sound. Warning lights flashing slowly torque system. When jib frame work scope to work limit, when the lifting load and torque reaches equipment when the permitted load limit moment send urgent alarm beeping sound. Shortness of torque system alarm indicating red light flashing. Torque protection function Control output function: when boom amplitude limit close to work, work when lifting load and torque device close to the permitted load limit, the system output torque control signal to stop the crane continue to continue to run in the direction of risk, allow crane moves in the direction of security. 2. Data control box 3. SHL Rope Rider three-pully load sensor 4. Boom angle-length sensor 5. GJ type A2B switch