A File Transfer Method Based on Modbus Protocol

Aiming at the demand for file transfer via fieldbus in power system terminal equipment and the lack of application cases of common file transfer protocols in fieldbus, this paper proposes a file transfer method based on Modbus protocol. The method is based on Modbus basic function code, and uses the TFTP-like protocol embedded in Modbus data frames for file transfer. The specific format of the transfer frames is proposed, the frame interaction process of file transfer is described, and the error control mechanism and failure exit mechanism during the transfer process are analyzed. The Modbus protocol-based file transfer is implemented. The experimental results show that the method can achieve reliable file transfer between master and slave devices. Compared with other file transfer methods, the method is simple, highly portable, and suitable for Modbus communication networks with low requirements for file transfer speed.