Communication system for field bus hybrid networking and method thereof

Abstract

The invention discloses a communication system and method for field bus hybrid networking, and the system comprises two DP transceiver circuits which are connected with a DP bus in parallel, the two DP transceiver circuits are respectively connected with an FPGA through a first isolation capacitor coupler, the FPGA is connected with two parallel MAU circuits through a second isolation capacitor coupler to form two parallel channels, and the two MAU circuits are connected with a PA bus; the FPGA is connected with the MCU through an SPI bus, and the MCU is connected with the redundancy mode setting dial switch and the DP baud rate setting dial switch; the DP bus is connected with a DP master station and a DP slave station which are cascaded, the DP master station sends data to the DP slave station, the outgoing line direction of the DP slave station is connected to the next-level DP slave station, and the DP slave station returns a response message; and the PA bus is connected with a PA instrument, and the PA instrument returns a response message to the DP master station after receiving a corresponding DP master station message frame, so as to complete the receiving of the frame message. According to the invention, the communication rate is improved.

Description

technical field [0001] The invention belongs to the field bus field, and in particular relates to a communication system and method for field bus hybrid networking. Background technique [0002] The system in the field of thermal power generation has the characteristics of high reliability requirements, many and complex monitoring equipment and objects, and high real-time requirements. In the control system, a large number of pressure transmitters, liquid level gauges, temperature, acidity, flow and other instruments and various execution instruments are used. institutions and other equipment. In this type of system, there are both process control loops and transmission control loops, and there are even occasions where intrinsic safety requirements exist. If the Profibus bus is used as the control system equipment layer network to connect Profibus DP devices and Profibus PA field instruments, then a Profibus DP / PA coupler is required to connect the Profibus PA instruments t...

AI Technical Summary

Problems solved by technology

[0003]Profibus DP / PA coupler realizes the conversion between Profibus DP RS485 (asynchronous, NRZ) and Profibus PA signal (synchronous, Manchester code), Profibus DP network The rate can be changed, flexible and changeable from 12M to 9600bps, the higher the rate, the shorter the communication distance, and the Profibus PA network communication rate is fixed at 31.25Kbps, so, in conventional applications, if there is a PA network connected to the DP network, the DP network needs to be The communication rate is lowered to 45.45Kbps. In actual engineering applications, considering the system scale, real-time bus communication and cost, the DP network rate is generally set to 500Kbps, so the conventional Profibus DP / PA coupler is difficult to meet this application scenario.

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