Competition model RS-485 bus multimaster communication system and working method thereof

Abstract

A competition model RS-485 bus multimaster communication system and a working method thereof relate to a communication system. At present, the data transmission time of the nodes on an RS-485 bus is long, and the nodes only can detect the conflict of the bus while can not avoid actively, once the conflict occurs, competition needs to be carried out again. The competition model RS-485 bus multimaster communication system of the present invention comprises a plurality of nodes and an interface chip, and is characterized in that the nodes are equipped with an XNOR gate circuit, a double-path D-type rising edge trigger and an XOR gate circuit, and the output end of the XOR gate circuit and a node receiving signal end are connected with the interface chip; a first resistor is arranged between the anode output end of the interface chip and the anode of a power supply, and a second resistor is arranged between the cathode output end of the interface chip and a grounding end. The competition model RS-485 bus multimaster communication system and the working method thereof of the technical scheme are based on a hardware conflict detection mode, and take the bit as the unit. Once the conflict occurs, the failed party quits automatically, and the party obtained the control right can send the data continuously, thereby guaranteeing that the data is sent correctly.

Description

technical field [0001] The present invention relates to a communication system. Background technique [0002] Such as figure 1 As shown, in the traditional RS-485 bus, there is always a unique master node, and other nodes are all slave nodes. Its working process is as figure 2 As shown, the communication is always initiated by the master node. After receiving the command, the slave node obtains the control right of the bus, and then sends information to the bus. After sending, the bus control is returned to the master node. Slave nodes can only send data when inquired by the master node, so emergency data such as alarms cannot be transmitted; slave nodes cannot communicate with each other, and can only be transferred through the master node, which affects the speed. In order to improve node data transmission, a competition mechanism of bus monitoring bus is introduced, and its workflow is as follows image 3 As shown, the bus monitoring bus competition mechanism relies...

AI Technical Summary

Problems solved by technology

It needs to add a software module for node competition in the CPU. Due to the need for software processing and judgment time, the node data transmission time is long, and it can only detect bus conflicts and cannot actively avoid them. Once conflicts occur, communication fails and competition needs to be re-competed

Images