PLC system and master-slave connection structure thereof

Abstract

The invention provides a PLC system and a master-slave connection structure thereof. The PLC system comprises a host and multiple slave machines. The data interaction interface of the host and the data interaction interfaces of multiple slave machines are connected to a communication bus. The address signal interface of the host and the address signal interfaces of multiple slave machines are connected in series in turn through a data line. The host outputs an address signal when the host is electrified, and the host transmits the address signal to each slave machine through the data line so as to allocate address for each slave machine. The host and each slave machine mutually transmit a differential signal through the communication bus so as to realize data interaction. According to the improved master-slave connection structure of the PLC system, the differential signal is transmitted between the host and the slave machines through the communication bus to realize data interaction between the host and the slave machines, and the address signal outputted by the host is transmitted to the slave machines through the data line to allocate the address for the slave machines so that the communication rate between the host and the slave machines of the PLC system can be effectively enhanced, the anti-interference capability can be enhanced, and the cost is low and the structure is easy to implement.

Description

technical field [0001] Embodiments of the present invention belong to the technical field of PLC (Programmable Logic Controller, programmable logic controller), and in particular relate to a PLC system and its master-slave connection structure. Background technique [0002] In the PLC system, the PLC system usually includes CPU (Central Processing Unit, central processing unit) module, I / O (Input / Output, input and output) module, power supply module and other modules, and the number of other modules can be expanded according to actual needs . The CPU module of the PLC system acts as the master, and the other modules act as slaves. The data exchange between the master and the slaves is carried out by means of bus communication. [0003] However, the existing communication method that only realizes data interaction between the master and slave of the PLC system through the SPI bus has defects such as low communication rate and weak anti-interference ability, and cannot adapt ...

AI Technical Summary

Problems solved by technology

[0003] However, the existing communication method that only realizes the data interaction between the master and slave of the PLC system through the SPI bus has defects such as low communication rate and weak anti-interference ability, and cannot adapt to the gradually increasing industry development requirements.

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