Cause : Option Communication Error comes when the connection was lost after establishing initial communication or when the run command frequency reference is assigned to an option card.

1. No signal was received from the PLC or faulty communications wiring or an existing short circuit.

• Check for faulty wiring.
• Correct the wiring.
• Check for disconnected cables and short circuits and repair as needed.

2. Communication data error occurred due to noise .

• Check the various options available to minimize the effects of noise.
• Counteract noise in the control circuit, main circuit, and ground wiring.
• Ensure that other equipment such as switches or relays do not cause noise. Use surge absorbers if necessary.
• Use only recommended cables or other shielded line. Ground the shield on the controller side or the
drive input power side.
• Separate all communication wiring from drive power lines. Install an EMC noise filter to the drive power supply input.

3. The option card is damaged.

• Replace the option card if there are no problems with the wiring and the error continues to occur.

4. The option card is not properly connected to the drive.

• The connector pins on the option card do not line up properly with the connector pins on the drive.
• Reinstall the option card.