The connection has been broken for an unspecified reason

What does ERR_CONNECTION_BROKEN mean?

An established Modbus TCP connection was unexpectedly terminated. This indicates a loss of communication between the client and server without a graceful shutdown, often due to network issues or the remote peer failing.

• Physical network disconnection (e.g., cable unplugged, network interface failure).
• Remote device power loss, crash, or unexpected shutdown.
• Network router/switch failure or excessive network latency/packet loss.
• Firewall timeout or connection reset by an intermediate network device.

Click steps to track your progress.

1. 1

   Verify physical network connectivity between the controller and the remote Modbus TCP device.

2. 2

   Check the operational status of the remote Modbus TCP device to ensure it is powered and running.

3. 3

   Inspect network infrastructure (routers, switches) for faults or configuration issues.

4. 4

   Adjust firewall settings to prevent connection timeouts if applicable and permissible.