Communication control Analog control: The analog control background can send a current of 4-20mA to control the opening of the valve. Serial communication: This method only requires fewer cables and can achieve human and communication. Users can obtain valve operating information, suitable for RS485, RS232, RS422 interfaces. Fieldbus (Profibus or Lonwork): Typically suitable for industrial applications. All devices can be connected through a single data cable, which has a high cost-effectiveness.