Variable frequency drive (VFD) is a power control device that uses frequency conversion technology and microelectronics technology to control the AC motor by changing the frequency of the motor's working power supply. The variable frequency drive is mainly composed of rectification, filtering, inverter, braking unit, driving unit, detection unit and micro-processing unit. It adjusts the voltage and frequency of the output power supply by switching on and off the internal IGBT, and provides the required power supply voltage according to the actual needs of the motor, thereby achieving the purpose of energy saving and speed regulation. In addition, the VFD has many protection functions, such as overcurrent, overvoltage and overload protection, etc. Now, we will talk about ATO VFD analog output setting and wiring.