| Compared with the traditional Ethernet network, the most distinguished difference of industrial Ethernet is its fast-certain communication. This project focuses on R&D of industrial Ethernet, especially on the difference of EPA certain communication and the communication standard of the traditional Ethernet, and the conclusion is that the field devices in the EPA network are not restricted by the 5-4-3 principle, which means more series repeaters can be used in the industrial Ethernet.More series repeaters will introduce more shrinkage of inter-frame-gap and the total delay of data transmission, aim at this problem, a new solution for repeater's data transmitting is proposed based on double-bits data transmitting model and compensation-feedback, and the delay of repeater's data transmission and the shrinkage of inter-frame-gap can both be controlled. The Manchester decoder/encoder, the double-bits data transmitting and the means of controlling the shrinkage of inter-frame-gap are all carried out in the FPGA chip. This proposition is emulated by the wave emulation.While the programs are being carried out in the FPGA chip, the signal from the network is received and sent by the analog circuit around the FPGA chip. The analog circuit is designed according to the IEEE 802.3 standard using high quality OP amplifiers.The following chapters covered every contents of the design, including solution carried out and verification, repeater soft-core design, system hardware development and debug. |
