Communication method, communication device, communication system and storage medium based on modbustcp protocol

Abstract

The invention discloses a communication method, a communication device, a communication system and a storage medium based on the ModbusTCP protocol. The communication method based on the ModbusTCP protocol comprises the steps of: obtaining the register read number of the request data packet and the data domain length of the returned data packet; according to the register read number and the data domain length, setting up the request data packet Correspondence with the returned data packet. The communication equipment includes a data transceiver and a processor, the data transceiver is used to send a request packet and receive a return packet, and the processor is used to obtain the number of register reads of the request packet and the length of the data field of the return packet, and is used to The number of registers read and the length of the data field are used to establish the corresponding relationship between the request data packet and the return data packet. The communication method, communication device, communication system and storage medium based on the ModbusTCP protocol of the present invention can improve communication efficiency and communication reliability.

Description

technical field [0001] The invention relates to the technical field of network communication, in particular to a communication method based on the ModbusTCP protocol, a communication device, a communication system and a storage medium. Background technique [0002] The Modbus protocol is an industrial fieldbus protocol standard, and the ModbusTCP protocol is a Modbus protocol based on Ethernet TCP / IP. The ModbusTCP protocol request packet format includes: transaction identifier, protocol identifier, length, unit identifier, function code, starting register address, and the number of registers read. The returned data packet format of the normal response of the ModbusTCP protocol includes: transaction identifier, protocol identifier, length, unit identifier, function code, data field length, and data field. [0003] In actual use, some equipment manufacturers do not fully comply with the ModbusTCP protocol format when using this protocol, and the transaction identifier is oft...

AI Technical Summary

Problems solved by technology

If the host requests multiple times and the slave device responds multiple times, but because there is no transaction identifier in the returned data packet, or the transaction identifier is a default fixed value, it will appear that after the host receives multiple response packets, it cannot Corresponding to the relationship between request and response, which leads to the problem of indistinguishable parsing, which seriously affects the data communication rate between devices

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