1024AirConditioner-526互联

import serial
import crcmod

def getCrc16(veritydata):
    if not veritydata:
        return
    crc16 = crcmod.mkCrcFun(0x18005, 0xFFFF, True, 0x0000)
    return crc16(veritydata)

def getModbus04(addr, startRegAddr, regNum, funCode=4):
    if addr < 0 or addr > 0xFF or startRegAddr < 0 or startRegAddr > 0xFFFF or regNum < 1 or regNum > 0x70:
        return
    sendBytes = addr.to_bytes(1, byteorder="big", signed=False) +\
                funCode.to_bytes(1, byteorder="big", signed=False) +\
                startRegAddr.to_bytes(2, byteorder="big", signed=False) +\
                regNum.to_bytes(2, byteorder="big", signed=False)
    crcCode = getCrc16(sendBytes)
    sendBytes += crcCode.to_bytes(2, byteorder="little", signed=False)
    return sendBytes

if __name__ == '__main__':
    last_state = 0
    com = serial.Serial("com1", 38400, timeout=0.2)
    while True:
        sendBytes = getModbus04(1, 0, 1)
        com.write(sendBytes)
        readBytes = com.read(1*2+5)
        if readBytes[4] == 1:
            if last_state == 0:
                print("1\n")
                file = open(r"D:\PycharmProjects\temp\new_file.txt", "w")
                file.close()
                last_state = 1
        else:
            last_state = 0