MEMOBUS/Modbus Communication Error

What does CE mean?

This minor fault indicates that control data was not received correctly for two seconds, primarily due to noise interference or incompatible communication settings. Noise can corrupt data transmission, while incorrect protocol settings or a too-short CE detection time can prevent proper communication. Unresolved, this fault prevents the drive from receiving critical control commands, leading to loss of control over the connected equipment.

• High levels of electromagnetic interference (EMI) or radio-frequency interference (RFI) corrupting data packets on the communication line.
• Incorrect communication parameters (e.g., drive address b5-01, baud rate b5-02, data format b5-03) mismatch between the drive and the master controller.
• Loose or improperly shielded communication cabling, allowing noise ingress or poor signal transmission.
• Communication timeout setting (e.g., b5-08) on the drive is too short for the network traffic or the master controller's polling interval.
• Master controller not sending valid Modbus/MEMOBUS requests, or experiencing its own internal communication issues.

Click steps to track your progress.

1. 1

   Verify the drive's slave address (b5-01), baud rate (b5-02), data format (b5-03), and communication timeout (b5-08) parameters match the master controller's settings exactly.

2. 2

   Ensure communication cables are properly shielded, grounded at one end (typically the master end), and routed away from high-current power cables or inductive loads.

3. 3

   Check the termination resistor settings (e.g., internal DIP switch SW1) on the drive and all other devices on the Modbus/MEMOBUS network.

4. 4

   Use a Modbus/MEMOBUS protocol analyzer tool to monitor data traffic and identify corrupt packets, incorrect addressing, or communication timing issues.

5. 5

   Temporarily increase the communication timeout parameter (b5-08) in the drive to see if the fault clears, indicating a timing sensitivity.