Implementing Redundancy in the SDG for OPC UA Output

Implementing Redundancy in the SDG for OPC UA Output

Step 1: Create the Channels

Configure the necessary channels to connect to the OPC DA servers.
// Make sure each channel points to the correct server: primary and secondary.

Verify that both channels are active and can read tags independently.
// This ensures that data can be received even if one of the servers fails.

Step 2: Configure the Internal MDO

Create an Internal MDO within the SDG to manage the redundancy logic.

Configure a conditional expression (if) within the MDO to evaluate the state of the primary server channel:

If the primary channel is active → read the tags from the primary server.

If the primary channel is inactive → read the tags from the secondary server.

This setup ensures that information remains available automatically, without manual intervention.

In this scenario, an if expression is implemented to evaluate the status of the channel connected to the primary OPC server.

• When the channel status is true, the T1 data from the primary server is transmitted.

• When the channel status is false, the T1 data from the secondary server is transmitted instead.

This ensures continuous data availability by automatically switching to the secondary server if the primary becomes unavailable.

Step 3: Save and Verify the Redundancy

Save the configuration of the MDO and the channels.

Test the logic by disconnecting the primary channel to confirm that data is correctly redirected to the secondary server.