The AST420 Series Signal Converter is a device facilitates the conversion between analog signal an radio signal. It aims to convert 4-20 mA analog signal into radio signal to transmit the analog signal remotely without cable, which is widely used in the occasion of transmitting analog signals over long distances. The wireless communication distance is up to 600 meters, saving a lot of cables. It also isolates the power supply of the signal collection end and the control end of the device to improve the security.