Received packet is rejected

What does ERR_PACKET_REJECTED mean?

A received Modbus TCP packet was explicitly rejected by the controller. This might be due to security policies, internal resource limitations, or unsupported operations within the Modbus TCP server implementation, even if the packet format is valid.

• Packet fails internal validation checks beyond basic format and CRC (e.g., protocol violations).
• Internal controller state preventing packet processing (e.g., Modbus service temporarily offline).
• Security features rejecting packets from suspicious sources or with unusual characteristics.

Click steps to track your progress.

1. 1

   Review any security settings or filters configured on the Modbus TCP server that might reject valid packets.

2. 2

   Check controller logs for additional information regarding the specific rejection reason.

3. 3

   Ensure the Modbus TCP client is sending standard, expected Modbus requests, avoiding unsupported function codes.