Problem: After opening the serial port of the MCU with the serial port assistant written in labview for a period of time, I found that it has been in the state of failing to open the serial port. It can be successfully opened by changing another USB port, but it fails to open again after a while. But when using the serial port assistant XCOM to debug, the two sides can always communicate.
Solution: The receiving buffer of the labview serial port overflows, and the program has not been closed by visa, so the serial port cannot be opened. After the visa has been successfully closed, the receive buffer overflow can be cleared.