A 485 multi-master communication method and system based on single ring network

Abstract

The present invention provides a 485 multi-master communication method and system based on a single ring network, the system includes several 485 multi-master communication devices based on a single ring network, and the device is provided with two 485 communication ports: for sending The sending port of the data message and the receiving port used to receive the data message; the several 485 multi-master communication devices based on the single ring network are connected in pairs to form a ring network, and satisfy: the sending port of the previous device is the same as the one. The receiving ports of the latter device are connected; on the ring network, data packets can only be sent in one direction, forming a unidirectional data flow network; each of the 485 multi-master communication devices based on the single ring network has an address corresponding to it. The device includes: a data trigger mode configuration module, a data destination address configuration module, a data active sending module and a data receiving processing module, which are connected in sequence. The invention effectively solves the problem of low efficiency of traditional 485 communication.

Description

technical field [0001] The invention relates to the field of automation and communication, and in particular to a 485 multi-master communication method and system based on a single ring network. Background technique [0002] The 485 communication network is a digital multi-point system using differential balanced transmission. It generally adopts a master-slave communication method, that is, a master with multiple slaves, and at the same time, a half-dual between the master and multiple slaves is used. Therefore, the 485 communication network is widely used because of its low cost and simple design. [0003] At present, the half-duplex communication technology used in the 485 communication network can only be used by the host to query the slave for response, that is, the host polls the slaves on the bus one by one, and the slave responds to the host according to the polling mechanism, thereby avoiding the 485 communication network. The two subjects are in the sending state ...

AI Technical Summary

Problems solved by technology

This method increases the complexity of hardware design, and the design of the arbitration line will affect the transmission distance of the bus; in addition, the arbitration line is shared by all nodes. When multiple nodes need to send data at the same time and seize the arbitration line, each node The idle time of the bus is determined according to the node address. The smaller the node address, the smaller the delay, the easier it is to occupy 485 bus resources, and the larger the node address is, the longer the delay is, the less likely it is to occupy 485 bus resources. , the data transmission efficiency of a node with a large address will be lower than that of a node with a small address

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