485 bus type monitoring system and its high extendibility method

Abstract

The invention discloses a 485 bus monitoring system and a high expansibility method thereof, comprising a main device node and a slave device node. Without the additional artificial configuration, the main device node monitors an adding system and a withdrawing system of the salve device node. The quantity of the device nodes is increased or reduced flexibly or the hot-swap is implemented. Conflicts of device addresses and recognizing problems of the main device node are not needed to be considered. Therefore, the high expansibility and the adaptability of the controlled nodes in the 485 bus monitoring system are realized. The method solves the inconveniences of the node configuration in the 485 bus monitoring system and the weakness that the expansibility of the system is not strong.

Description

technical field [0001] The invention relates to a flexible configuration method of a 485 bus type monitoring system, which realizes high scalability of the system by supporting node hot plugging technology. Background technique [0002] In the field of multi-node industrial monitoring, the 485 bus system is a commonly used low-cost solution. Although the 485 bus only stays on the specification of the physical layer compared with the data link layer protocol of the CAN bus that supports competitive data transmission, it seems rudimentary, but its low cost and simple design advantages make it still have a wide range of applications. [0003] The biggest weakness of the 485 bus structure lies in the exclusiveness of the bus. 485 only supports the bus structure of one master and multiple slaves. There can only be one master device on the bus, and multiple slave devices are connected to the bus. At the same time, only one device can occupy the bus to send data, and other device...

AI Technical Summary

Problems solved by technology

[0003] The biggest weakness of the 485 bus structure lies in the exclusiveness of the bus.

Its problems are: first, it increases the difficulty of circuit design and increases the cost; second, when the number of nodes is small and the communication is infrequent, this method will have a good effect, but when the number of nodes is large and the communication In the case of high density, the number and time of bus conflicts and waiting times will be increased, resulting in a reduction in the working efficiency of the system, and the degree of reduction in efficiency is unpredictable

There is a bottleneck, that is, when the system expands or the device is damaged or replaced with a new device, the master device cannot automatically identify and configure the slave device.

Therefore, one host corresponds to the application of several known devices, and the scalability is not strong

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