Overview

This manual introduces M4 series Serial to Ethernet Converters (Include USR-N510, USR-N520, USR-N540, USR-TCP232-410s and USR-TCP232-ED2, USR-TCP232-E2, USR-K3) Modbus Gateway function.

Modbus Gateway includes: Modbus RTU transparent transmission, Modbus ASCII transparent transmission, Modbus RTU<=>Modbus TCP protocol conversion, Modbus polling and serial port querying. In this manual, we take USR-TCP232-410S as a example to introduce Modbus Gateway and configure.

1.Configuration Method

User can configure module by setup software or Web Server. User can download setup software for M4 series Serial To Ethernet Converters from https://www.usriot.com/usr-tcp232-m4k3-setup-software/ and log in Web Server by entering module’s IP and username/password.(When user runs setup software to configure module or logs in Web Server on PC, user must ensure that module connects directly to PC by Ethernet interface or connects to router which in same network as PC by Ethernet interface.)

2.Modbus RTU<=>Modbus TCP

Set module in TCP Server or TCP Client mode, then user can set module with Modbus RTU<=>Modbus TCP function. Data transmission diagram as follow:

User can enable Modbus RTU<=>Modbus TCP function by setup software or Web Server as follows:

3.Serial Port Querying

 User can realize Modbus serial port querying function by serial heartbeat packet function. User should enable serial heartbeat packet function and modify heartbeat packet data to Modbus querying commands by Web Server as follow:

4.Modbus Polling

 Modbus polling function diagram as follow:

User can enable Modbus polling function and configure timeout time by Web Server as follow: