In order to implement non-polar transmission of the data, in this paper, we took a new way to solve the problem by automated correction method, which used the RS485 standard as physical layer protocol, used multi-function meter Convention (DL/645-1997) as implementation layer protocol, and implemented the data transfer protocol in the FPGA platform data transfer protocol. This paper introduced the design way, simulation waveforms and measured results, and solved reserve connection of the traditional polarity RS485 communication.