Modbus Communication Error

What does CE mean?

Control data was not received correctly for two seconds over the Modbus connection. This implies a broken Modbus connection or the master device has stopped communicating, preventing proper control and data exchange.

• Physical break in the Modbus communication cable (RS-485 A/B wires) or loose terminal connections.
• Incorrect Modbus communication parameters (e.g., baud rate S5-02, parity S5-03, address S5-01) mismatch between drive and master.
• Missing or incorrect termination resistors (120 Ohm) at both ends of the Modbus network segment.
• Modbus master device has stopped transmitting data or is faulty.
• High electrical noise or electromagnetic interference (EMI) on the Modbus line causing data corruption.

Click steps to track your progress.

1. 1

   1. Verify Modbus communication wiring (A, B, GND) for continuity and proper shielding between the drive and master controller.

2. 2

   2. Confirm that Modbus parameters S5-01 (Drive Address), S5-02 (Baud Rate), and S5-03 (Parity) match the master device settings.

3. 3

   3. Check for proper 120 Ohm termination resistors at the first and last devices on the Modbus network segment.

4. 4

   4. Using a Modbus sniffer or diagnostic software, monitor Modbus traffic to analyze communication integrity and packet loss.

5. 5

   5. Cycle power to both the drive and the Modbus master device to clear any temporary communication glitches.