Profibus-DP communication protocol redundancy master station

Abstract

The invention discloses a profibus-DP communication protocol redundancy master station which comprises a master station communication card and a master station backup card; the master station communication card is in a working state, exchanges data with a slave station through a display port (DP) interface circuit, and exchanges data with a central processing card piece through a dual port RAM (DPRAM) interface circuit; the master card communication card periodically backs up the parameter set of the master station communication card and the real-time input / output (I / O) data of the slave station to the master station backup card; and the master station backup card is in a heat backup waiting state, takes over the work of the master station communication card when the master station communication card fails to work, and periodically receives the parameter set of the master station communication card sent by the master station communication card and the real-time I / O data of the slave station. According to the Profibus-DP communication protocol redundancy master station, a working master station is not required to work together with a backup master station, can be connected with a DP slave station or directly connected with the redundancy master station products of the DP slave station; and the defects caused by the redundancy method of an existing master station that the selection of master station products is greatly restricted and the cost is increased after the single-DP slave station is connected in are overcome.

Description

technical field [0001] The invention belongs to the technical field of field bus redundancy, and relates to a Profibus-DP field bus communication protocol redundant master station and a redundant mode. Background technique [0002] Profibus field bus is an open, all-digital, serial communication bus with a wide range of applications. It is a major breakthrough in the transformation from centralized automation system to decentralized automation system. The Profibus communication protocol adopts information redundancy technology. For example, the Profibus-DP physical layer adopts RS485 differential mode, non-return-to-zero NRZ, and asynchronous transmission signals, and the data link layer message adopts HD=4 Hamming distance and CRC code verification Wait. The current industrial control field puts forward higher requirements on the reliability of the control system. There is no doubt that redundancy technology is a way to achieve high reliability. [0003] When discussing r...

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Problems solved by technology

[0007] The above master station redundancy method requires the working master station and the standby master station to exchange data with the slave station at the same time, which has high requirements on the master station and has great limitations in product selection; and in this redundancy method, a single DP must be connected. port slave station, network components must be added, which increases the cost

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