A software design method of Modbus protocol based on MSP430 single-chip microcomputer

The paper analyzed Modbus protocol specification, introduced a software design method of Modbus communication protocol realized by single-chip microcomputer taken MSP430 as example. The method divides communication process into four process: message reception, message receiving to send, transmission, sending to receive, and reasonably assigns communication tasks including message receiving, checking, unpacking, packing and responsing, which realizes modular programming of the Modbus protocol.