Socket error during Listen operation

What does ERR_SOCKET_LISTEN mean?

An error occurred during the socket listen operation. This prevents the Modbus TCP server from listening for incoming client connections on the designated port, often indicating a port conflict or permission issue.

• Modbus TCP port (default 502) is already in use by another application.
• Insufficient privileges for the Modbus TCP server to listen on the specified port.
• Network configuration issue preventing the listen operation.

Click steps to track your progress.

1. 1

   Verify no other application or service is using the Modbus TCP port (default 502).

2. 2

   Check network configuration for potential port conflicts or incorrect port assignments.

3. 3

   Restart the controller to attempt clearing the port if it's in a stuck state.