Method for converting Modbus TCP (Transmission Control Protocol)/IP (Internet Protocol) into Modbus serial gateway

The invention relates to a method for converting a Modbus TCP (Transmission Control Protocol)/IP (Internet Protocol) into a Modbus serial gateway. Equipment response data is stored in a gateway arranged between a server and a serial network; after the server sends a read order to the gateway, the gateway searches the read order in an order list; if the order list has the read order, data is directly read from a cache corresponding to the order and is returned to the server; otherwise, the read order is converted by the gateway and is sent to the serial network; the read order obtains the equipment response data corresponding to the server, which is returned after response, and the gateway records the read order and caches the equipment response data corresponding to the read order simultaneously; and after the server sends a write order to the gateway, the gateway directly converts the write order and sends the write order to the serial network, so that the data cache in the gateway is successfully updated.