Abstract: The paper designs a serial server based on Direct-Net that supports next generation Internet communication protocol named as IPv6 to make single point signal controllers be networked based on IPv4 or IPv6, which has a certain practical significance for the development of intelligent transportation, Internet of Things and other fields. In the IPv4 and IPv6 environment, the PC client can communicate with the single point signal controller through the serial server to achieve the functions of remotely monitoring and controlling running state in the field. After testing, the reliability, stability, functionality and other indicators of system have reached the design requirements.