Cause : MEMOBUS/Modbus Communication Error comes when control data was not received correctly for two seconds.

1. A data error occurred due to noise.

• Check options available to minimize the effects of noise.
• Take steps to counteract noise in the control circuit wiring, main circuit lines, and ground wiring.
• Reduce noise on the controller side.
• Use surge absorbers for the magnetic contactors or other components that may be causing the disturbance.
• Use only recommended shielded line. Ground the shield on the controller side or on the drive input power side.
• Separate all wiring for communication devices from drive input power lines. Install an EMC noise filter to the drive input power supply.

2. Communication protocol is incompatible.

• Check the H5 parameter settings and the protocol setting in the controller.
• Ensure settings are compatible.

3. The CE detection time (H5-09) is set shorter than the time required for a communication cycle to take place.
• Check the PLC.
• Change the software settings in the PLC.
• Set a longer CE detection time using parameter H5-09.

4. Incompatible PLC software settings or there is a hardware problem.
• Check the PLC.
• Remove the cause of the error on the controller side.