Alotcer industrial gateway supports standard embedded OPC UA protocol, which can convert PLC device data into standard OPC protocol data, and realize the function of OPC system to access diversified PLC device data. Currently, it can be connected to protocol devices such as Modbus RTU, Modbus TCP, and Modbus RTU Over TCP.

Alotcer industrial gateway

Test environment:

LAN test, router local IP (, OPCUA client (, Modbus simulation tool

test tools:

1. Modbus Salve — Modbus equipment simulation debugging tool

2. UaExpert — OPCUA’s GUI tool

Testing process:

1. Add Modbus type devices (ModbusRtu, ModbusTCP, ModbusRtuOverTCP) in router interface configuration, add device register mapping table (format: register name, data type, register address, register length; data type selection: SByte|Byte|Int16|UInt16|Int32 |UInt32|Int64|UInt64|Float|Double|StringSTRING type is string length, other types greater than 1 will generate an array; eg:reg1,String,1,6;)

Add Modbus type devices

router interface configuration

2. Set OPCUA server port (default 4840, can be changed according to needs, be careful not to conflict with other ports)

Set OPCUA server port


3. Modbus Salve settings

Device1 Modbus RTU setting screenshot

Device1 Modbus RTU setting

Modbus Salve settings


Device2 Modbus TCP setting screenshot

Device2 Modbus TCP setting

Modbus TCP setting


Device3–Modbus Rtu Over TCP setting screenshot

Modbus Rtu Over TCP setting


Modbus Rtu Over TCP setting

4. OPCUA client configuration

OPCUA client configuration


5. After connecting to the OPCUA server, the client generates a device file (registered mapping file), and pulls the file to the Data Access View interface (the data will change with the Modbus device data)

connecting to the OPCUA server

connecting to the OPCUA server