High-speed RS485 energy/data transmission terminal

Abstract

The invention relates to a high-speed RS485 energy / data transmission terminal which belongs to the field of data transmission technology in an industrial site bus. The transmission terminal comprises an FPGA device, a RS 485 interface unit, a network transformer unit, a terminal impedance matching unit and a DC energy unit, wherein the network transformer unit is respectively connected with the DC energy unit and the terminal impedance matching unit and is also connected with the FPGA device by the RS 485 interface unit. The method comprises the following steps: the terminal reads data, codes the data, carries out parallel / series conversion of the data and then overlays the data with DC energy signals to carry out long-line transmission; after the signals are received by the next level terminal, the serial data is separated from the DC energy signals to extract DC energy signals and detect the DC energy signals, and the original transmission data signals are extracted from the DC energy signals which is carried out parallel / series conversion and decoding. The invention has simplified peripheral hardware design, can increase data transmission rate, extend a transmission distance, has a simple hardware circuit, can be flexibly controlled and is convenient to expand the number of RS 485 transmission nodes.

Description

technical field [0001] The invention belongs to the technical field of data transmission of industrial field bus, and in particular relates to a high-speed data transmission terminal based on RS485 bus, which is used for high-speed and long-distance data transmission of monitoring parameters along the RS485 bus in the industrial field. Background technique [0002] The RS485 bus system has the advantages of simple hardware design, convenient control, low cost, and long transmission distance. It is widely used in industrial control, community monitoring, water regime monitoring, seismic exploration and other fields, among which RS (Recommended Standard) represents the recommended standard. At present, at home and abroad, the existing general-purpose RS485 bus is mainly used for the design of the data transmission part in the measurement and control system or the conversion between different interface standards (for example, the data conversion between RS485 and RS232, or betwe...

AI Technical Summary

Problems solved by technology

In 2004, Clark K pointed out that the amplitude and frequency of signal attenuation during long-distance transmission are related to the characteristics of the cable, and intersymbol interference will occur during high-speed transmission, resulting in signal distortion

Journal of Instrumentation, 2006, 27(6): 2458-2459), but the research in China is mainly to realize the application of RS485 bus under conventional indicators, such as the general data controller based on RS485 bus, and the interface between RS485 and RS232 or USB The conversion of RS485 high-speed data transmission technology is very little

Moreover, the existing RS485 bus system mainly focuses on realizing data communication between different nodes in the distributed monitoring system, and rarely involves superimposed transmission between data and DC energy in the bus

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