Examples

Linking a Modbus tag to an OPC UA tag

This example demonstrates how to link a Modbus tag to an OPC UA tag, such as reading commands from a Modbus device and writing them to an OPC UA tag. In this case, the input tag is the Modbus tag, and the output tag is the OPC UA tag. The tags will be named /Modbus/Command and /OPC UA/Command, with the former having read/write permissions.

The screenshot below demonstrates the real-time status of the command tags. The Modbus/Command tag acts as the source, receiving data directly from a Modbus Client module; therefore, it is set to Read-only (R). In contrast, the OPC UA/Command tag has Read/Write (RW) access. This configuration allows the Linked Tags agent to read the value from the Modbus source and write it into the OPC UA tag, effectively synchronizing the two systems.

The next step is to configure the Linked Tags module to establish a unidirectional synchronization. As illustrated below, map the /Modbus/Command tag to the Input property and the /OPC UA/Command tag to the Output property. This configuration ensures that any value received from the Modbus client is automatically written to the OPC UA tag.