what is modbus gateway

Modbus gateway is a device that can convert Modubs TCP protocol into Modbus RTU protocol. You can understand it this way, it is an industrial router that supports the modbus protocol. I believe you will understand it better if you call it this way. Modbus is widely used in the field of instruments and sensors to obtain data from instruments and sensors.

Why does modbus gateway appear?

Because the traditional RS485-based Modbus RTU (or ASCII) has poor speed and scalability, a network-based protocol such as Modbus TCP later appeared. Compared with the traditional modbus RTU protocol, the Modbus TCP protocol is faster and has better scalability!

This is why converters such as Modbus gateways came into being. It supports more protocols and more interfaces. Modbus gateways on the market now generally support 8 working modes: TCP client, TCP server, UDP client, UDP server, RTU_Master–TCP_Slaver, TCP_Master–RTU_Slaver, ASCII_Master–TCP_Slaver, TCP_Master–ASCII_Slaver.

Note: The mobus protocol transmitted over TCP is completely different from the modbus TCP protocol.