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我正在尝试编写一个脚本来从 modbus TCP 设备读取保持寄存器并将解码的 UINT32 插入 MySQL ：

  1. 使用 pymodbus 读取 2 个寄存器
  2. 解码成 uint32
  3. 将解码后的值插入 mySQL
  4. 每 x 分钟重新开始

我不是程序员，也不是发现 Python。

我尝试了这个似乎可以工作的代码，但我不明白所有内容，我不知道它是否是使用“线程”的正确解决方案。你有更好的给我吗？

谢谢

import time
import pymysql.cursors
from pymodbus.constants import Endian
from pymodbus.payload import BinaryPayloadDecoder
from threading import Thread, Lock
from pyModbusTCP.client import ModbusClient

# connect database
#sqlconnection = pymysql.connect(host='127.0.0.1',
#                             user='root',
#                             password='',
#                             database='database',
#                             charset='utf8mb4',
#                             cursorclass=pymysql.cursors.DictCursor)

# read devices informations (ID, IP, Port, Register address)
#with sqlconnection:
#    with sqlconnection.cursor() as cursor:
#        sql = "SELECT `dev_id`, H0.hw_address, H0.hw_port FROM `devicestatus` LEFT JOIN `hardware` H0 ON H0.hw_id = devicestatus.dev_hw_id WHERE H0.hw_enabled = 1 AND devicestatus.dev_used = 1 ORDER BY H0.hw_address, dev_name"
#        cursor.execute(sql,)
#        result = cursor.fetchall()



# sample of result
result = [{'dev_id': 7, 'hw_address': '127.0.0.1', 'hw_port': 502}, {'dev_id': 8, 'hw_address': '127.0.0.1', 'hw_port': 502}, {'dev_id': 9, 'hw_address': '127.0.0.1', 'hw_port': 502}]


# set global variables
regs = []
sf_value = 0


# init a thread lock
regs_lock = Lock()


# modbus polling thread
def polling_thread():
    global regs

    # polling loop
    while True:
        
        REGISTER_ADDRESS = 98 #First device is at address %MD100 (in Schneider M221 simulator), i dont' understand why i need to do -2

        # For each dictionary of the list, "extract" each value of element : information useful to launch Modbus requests, one per device.
        for val in result:
            # set modbusTCP variables :
            DEV_ID = val['dev_id']
            SERVER_HOST = val['hw_address']
            SERVER_PORT = val['hw_port']
            SERVER_ID = 1
            REGISTER_ADDRESS = REGISTER_ADDRESS + 2 # to read %MD100 %MD102 %MD104 ...
            REGISTER_COUNT = 2
            print("Target :", SERVER_HOST, SERVER_PORT, REGISTER_ADDRESS)

            client = ModbusClient(host=SERVER_HOST, port=int(SERVER_PORT), unit_id=int(SERVER_ID), auto_open=True, auto_close=True, timeout=2)
            
            # keep TCP open
            if not client.is_open():
                client.open()
            # do modbus reading on socket
            reg_read = client.read_holding_registers(REGISTER_ADDRESS, REGISTER_COUNT)


            # if read is ok, store result in regs (with thread lock synchronization)
            if reg_read:
                # decode the 2 registers into a 32 bit integer
                decoder = BinaryPayloadDecoder.fromRegisters(reg_read, byteorder=Endian.Big, wordorder=Endian.Little)
                sf_value = decoder.decode_32bit_int()

                with regs_lock:
                    regs = sf_value
                    print(regs)
                    # To do : insert each data into sql table
                    #with sqlconnection:
                        #with sqlconnection.cursor() as cursor:
                            # Create a new record
                            #sql = "INSERT INTO ...
        # x sec before next polling
        time.sleep(2)


# start polling thread
tp = Thread(target=polling_thread)
# set daemon: polling thread will exit if main thread exit
tp.daemon = True
tp.start()

# display loop (in main thread)
while True:
    # print regs (with thread lock synchronization)
    with regs_lock:
        #print(regs)
        print("What is this part ? everything is done in the polling_thread")
    # x sec before next print
    time.sleep(2)

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