multi-master-station token scheduling device, communication method and system based on MODBUS

Abstract

The invention discloses a multi-master station token scheduling device based on a MODBUS bus. The device comprises a first interface, a second interface and a controller, the first interface is connected with a main station; the second interface is connected with a slave station and other token scheduling devices through a bus; wherein a first address information configuration table and a second address information configuration table are stored in the controller, the first address information configuration table comprises slave station parameters, self-owned protocol addresses and fixed broadcast addresses, and the second address information configuration table comprises self-owned protocol addresses of other token scheduling devices; and the controller is configured to sequentially obtain the MODBUS bus control right through a preset token rotation mode and communicate with the corresponding main station. Through a token scheduling mechanism of the multi-master-station token scheduling device, MODBUS multi-master-station communication is realized.

Description

technical field [0001] The invention relates to the technical field of gateways, in particular to a multi-master token scheduling device, a communication method and a system based on a MODBUS bus. Background technique [0002] MODBUS-RTU bus is one of the most popular general industrial standard protocols in the world, which can be applied to various data acquisition and process monitoring. This protocol supports legacy RS-232, RS-422, RS-485 devices. Many industrial equipment, including PLC, DCS, and smart meters, are using MODBUS-RTU bus. MODBUS-RTU bus communication uses master-slave technology, that is, only one master station and multiple slave stations are allowed to perform digital communication on a MODBUS-RTU bus. The master-slave communication protocol of MODBUS-RTU bus determines that at any time Only one master station can exist for data collection. At present, in the practical application of MODBUS-RTU bus, there are more and more application requirements for...

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Problems solved by technology

[0003] However, this kind of multi-master communication through the use of communication converters has the following disadvantages: each master needs to be connected to the same communication converter, and when the master is far away, it will cause inconvenient installation and difficult wiring; At the same time, each master station needs to be connected to the independent MODBUS-RTU interface on the communication converter, and the number of master stations connected is limited by the number of interfaces; adding or reducing the master station requires changing the configuration of the communication converter. This will affect the communication data of the bus, and can not achieve non-disturbance; in addition, when the communication converter fails, the entire bus will fail, and the system reliability is low

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