Because the output voltage of the frequency converter is a PWM high-frequency pulse sequence waveform, its spectral envelope is a quasi sine wave, which contains harmonic components. Its transient voltage amplitude and frequency are very high, resulting in capacitance effect and induction of high voltage between the motor winding and the casing under strong electric field (the frequency converter casing also has a certain amplitude of static voltage). 

Therefore, there is a warning in the user manual of the frequency converter that requires reliable grounding, which is why. In addition, in industrial sites, there is usually no separate grounding wire and a neutral wire is used instead. Many equipment casings and frequency converters share the same system grounding wire, which will generate high voltage static electricity in the entire system. 

This high voltage will generate a strong electric field, which will interfere with the normal operation of the frequency converter. 

If this situation occurs, as long as a dedicated grounding wire for the frequency converter control system is buried separately, the fault can be eliminated.

1. Telephone inquiries with after-sales personnel, agents, etc;

2. Customers can determine by manually sending data: first, prepare an RS232 to RS48 serial port cable, computer, and serial port debugging software; Then connect the frequency converter to the computer through a serial port cable, open the serial port debugging software on the computer, set the communication parameters (the debugging software should be consistent with the frequency converter), and send the following data when the frequency converter is stopped;

1. Confirm whether the frequency converter is in operation and whether the FWD and REV indicator lights on the panel are on, as some parameters of the frequency converter are not allowed to be changed during operation;

2. Check if the parameters F2.13 for EDS1000 series, EDS800 series, and F2.16 for EDS2000 series are set to not allow modification;

1. Pressing the ESC key on the keyboard did not enter the functional parameter group, but instead resulted in four zeros appearing;

2. This is to set the user password for the customer. Please contact the agent to determine if it is set for the agent.

3. Collect machine information and contact the manufacturer.

1. The MODBUS protocol of the frequency converter only supports 03 (maximum reading of 10 registers) and 06 (single writing) command codes, and does not support continuous writing of command code 10. Communication failure may be due to incorrect command codes;

2. Communication format error, Eason only supports 8 data bits and does not support 7 bits, it may also be due to CRC verification error;

3. The baud rate, communication address, parity check, and frequency converter are inconsistent;

4. Reverse or incorrect connection of communication lines, such as

frequency converter has two communication protocols, "Free Protocol" and "MODBUS", while "MODBSU" has two versions, new and old. The main difference is that the communication register addresses are different. The old version supports both RTU and ASCLL formats, while the new version only supports RTU format;

Interference pathway: Aerial radiation, propagating in the air as electromagnetic waves;
Preventive measures: Communication cables should use shielded twisted pair and the shielding layer should be grounded;

Firstly, check whether the frequency converter parameter F0.00 is set to 03 or 10 (given by the serial port), and whether F0.02 is set to 03 or 04 (controlled by the serial port operation command); If there are no issues with the parameter settings of the frequency converter, check if there are any errors in the programming of the upper computer. Additionally, the frequency converter only supports single modification command code 06 and does not support continuous modification command code 10;

In terms of communication, if there are no issues with the parameters and wiring, check if the register address of the link variable established on the touch screen is correct. For example, Kunlun on state, Siemens PLC, rectangular PLC register addresses need to be increased by 1, and it is possible that the communication protocol version does not match;

1. Check if the wiring is properly connected and if the parameters are the same as the original settings;
2. Consult the after-sales engineer to confirm whether the communication protocol is consistent with the old frequency converter;
3. Check if the machine has communication function;

Being able to control the start stop indicates that there are no issues with communication parameters and wiring. The problem may lie in the programming of the touch screen. Check if the touch screen has read more than ten consecutive registers from the frequency converter. If it has read more than ten consecutive registers, the frequency converter will not recognize it, so communication errors may occur;