? What exactly is a Modbus gateway

A Modbus gateway is to convert a Modbus protocol frame into other protocol frames.For example, the data of Modbus RTU and Modbus TCP data can be converted to each other; the application development of master request and slave response can also be carried out to improve the efficiency of protocol conversion; The storage gateway replaces the host to initiate active reporting of Modbus requests. convert ethernet to wifi The device is in Modbus gateway mode to ensure the Modbus conversion efficiency to discard non-Modbus data and prevent interference to the serial bus. The difference between the three data frames The Modbus protocol defines a simple protocol data unit (PDU) that is independent of the basic communication layer and consists of function code (1Bit) + data (n Bit); Modbus RTU data frame: encoded in hexadecimal, including address field (1Bit) + PDU + CRC check (2Bit); Modbus TCP data frame: encoded in hexadecimal, including transaction identifier (2Bit) +rs232 to ethernet adapter protocol identifier (00 00: 2 bytes, indicating Modbus RTU protocol) + length (2Bit) + address field (1Bit) + PDU; Modbus ASCII data frame: encoded in ASCII, including start character (':') + address code (2 Bit) + data (0 to 2*255 Bit) + LRC check (2Bit) + line feed (CR, LF) )