Programmable logic controller (PLC) communication method based on universal serial bus (USB)

Abstract

The invention discloses a programmable logic controller (PLC) communication method based on a universal serial bus (USB), particularly relates to a PLC backboard communication method adopting a USB3.0 serial bus, and aims to provide a PLC communication method which is high in communication speed and high in instantaneity. According to the technical scheme, a plurality of USB concentrators are arranged on the USB backboard; the backboard communicating with the USB3.0 serial bus is adopted; a master controller, a USB expansion external module and a backboard power supply are arranged on the USB bus backboard; the USB expansion external module comprises a communication module, an input module and an output module; the master controller and the USB expansion external module are connected to the USB3.0 serial bus through the USB concentrators connected with the master controller and the USB expansion external module to finish data communication; and the master controller is connected with an upper machine, interacts data with the upper machine and controls downlink USB expansion equipment. The PLC communication method can be widely applied to the field of communication.

Description

technical field [0001] The invention relates to a PLC communication method based on a USB bus, in particular to a PLC backboard communication method using a USB3.0 serial bus communication. Background technique [0002] In the process of industrial control, continuous and long-term synchronous acquisition, recording and real-time processing of various high and low speed signals are required, and data integration on the Internet is required. [0003] At present, the PCI bus, CAN bus and Ethernet bus are generally used in PLC to complete the connection with the expansion module. Although the PCI bus has a high transmission speed (132Mbps) and the function of "plug and play", its disadvantage is that it can be plugged and unplugged. Troublesome, and the expansion slot is limited, generally 5 to 6; CAN bus data communication has the advantages of reliability, real-time and flexibility, but also has problems such as direct connection with the host computer and remote information ...

AI Technical Summary

Problems solved by technology

[0003] At present, the PCI bus, CAN bus and Ethernet bus are generally used in PLC to complete the connection with the expansion module. Although the PCI bus has a high transmission speed (132Mbps) and the function of "plug and play", its disadvantage is that it can be plugged and unplugged. Troublesome, and the expansion slot is limited, generally 5 to 6; CAN bus data communication has the advantages of reliability, real-time and flexibility, but also has problems such as direct connection with the host computer and remote information sharing; Ethernet Although the transmission rate of the bus can reach 100Mbps, the technology is relatively mature, but the Ethernet uses CSMA / CD, which cannot guarantee the real-time requirements of data transmission

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