Troubleshooting Modbus Poll: "Insufficient Bytes Received" Error Fixed
Common Modbus RTU settings: 8 data bits, Even parity, 1 stop bit (8E1). If your slave uses 8N2 (No parity, 2 stop bits), the master’s frame synchronization will fail.
In Modbus Poll, open . Look at the actual response packets. If the last 2 bytes (CRC) are sometimes missing: