Incoming Connection is rejected by the IP address validation

What does ERR_CONN_REJECTED mean?

An incoming Modbus TCP connection attempt was rejected because its source IP address did not pass the controller's configured IP address validation rules. This is a security feature to control access.

• The source IP address of the client is not in the allowed list configured on the Modbus TCP server.
• IP address validation is enabled and the client's IP is explicitly denied or not whitelisted.

Click steps to track your progress.

1. 1

   Review the Modbus TCP server's IP address validation settings in the controller configuration.

2. 2

   Add the client's IP address to the allowed list if it is a legitimate connection.

3. 3

   Temporarily disable IP address validation if it's not required for security, but exercise caution.