IWR1642BOOST: How to send the .cfg to radar through USB to boot the mmWave demo Visualizer?

I've flashed the .bin of the mmWave demo Visualizer using IWR1642BOOST. I tried to send the .cfg to the radar through python code but it didn't work. 

#serial_transmit

import serial
import time

ser = serial.Serial()

#open the port
def port_open(index, rate):
    ser.port = index
    ser.baudrate = rate
    ser.bytesize = 8
    ser.stopbits = 1
    ser.party = 'N'
    ser.open()
    if(ser.isOpen()):
        print("open_successfully!")
    else:
        print("open_fail!")

#close the port
def port_close():
    ser.close()
    if(ser.isOpen()):
        print("close_fail!")
    else:
        print("close_successfully!")

#send the cfg
def send_cfg(dest):
    length = len(open(dest).readlines())
    f = open(dest)
    for i in range(length):
        a = f.readline()
        if(ser.isOpen()):
            ser.write(a.encode('utf-8'))
            time.sleep(1)
    print("write_successfully!")

#main
if __name__ == "__main__":
    dest = "F:/DirEng/profile(1).cfg"
    port_open('COM6', 115200)
    send_cfg(dest)
    port_close()
    port_open('COM5', 921600)