b = bytes([230, 136, 145, 232, 166, 129, 232, 135, 170, 229, 173, 166, 231, 189, 145])

# print(b)

# #�L��(w��n)
# print(b[0])
# #
# # #����
# print(b.decode('utf8'))
# print(int.from_bytes(b[0:2]))
# #
# #�޸�
# b[0] = 20
#
# data = bytearray(b)
#
# print(data)
#
# data[0] = 20
# print(list(data))

mydata = bytearray(12)

mydata[0:1] = int.to_bytes(121,1)   #VB0
mydata[1:2] = int.to_bytes(-66,1,signed=True)   #VB1
mydata[2:4] = int.to_bytes(7878,2)       #vw2
mydata[4:8] = int.to_bytes(7677876,4)
import struct

mydata[8:12] = struct.pack(">f",89897.67)




if __name__ == '__main__':
    from snap7 import client


    def connect_plc() -> client.Client:
        plc = client.Client()
        plc.set_connection_type(3)
        plc.connect("192.168.5.20", 0, 1)
        return plc


    def write_to_plc(start_addr, byte: bytes):
        plc = connect_plc()
        plc.db_write(1, start_addr, byte)
        plc.disconnect()


    def read_plc(start_addr, num) -> bytearray:
        plc = connect_plc()
        data = plc.db_read(1, start_addr, num)
        plc.disconnect()
        return data

    write_to_plc(0,mydata)