After the RPR ( Resilient Packet Ring ) protocol draft has been proposed, RPR promptly becomes a hotspot of research. But the special RPR chips are not commercialized. This paper proposes a design scheme of the RPR module using a NP which does not support the RPR protocol and implement a protocol converter. The protocol converter mainly serves the functions of RPR / Ethernet frame conversion and interface conversion. The structure and function of the RPR module are described and the implementation of protocol converter is discussed.