import serial
import time

usb_relay = serial.Serial("COM17",9600)

if usb_relay.is_open:
   print(usb_relay)
   on_cmd = b'\xA0\x01\x01\xa2'
   off_cmd =  b'\xA0\x01\x00\xa1'
   usb_relay.write(on_cmd )
   time.sleep(1)
   usb_relay.write(off_cmd)
   time.sleep(1)

usb_relay.close()