Modbus设备无故停止通讯

-2

我的公司已经购买了几个具有modbus功能的房间温控器。那些来自中国。当我在Modbus RTU上与他们交流时，会发生有趣的事情。设备有时不会回应我。然后在接下来的民意调查中，他们有时会回应但最后，在一段时间之后，不管一小时还是两天，他们完全停止响应，并且我从modbus master获得一些错误。我使用串口分析器来查看发生了什么。我做了所有的硬件检查点（端接电阻等）。我尝试了许多modbus大师。但即使只连接了一个恒温器，也会发生问题。具体到这个问题，我用Python开发了自己的modbus master。最好的部分是，我使用最小的modbus库，每次调查后我都有机会关闭端口。但是，即使我的modbus主程序继续轮询，恒温器也会完全停止响应。不知何故，我必须通过编程来解决这个问题。我不能总是重新启动恒温器来解决通信问题。Modbus设备无故停止通讯

这里是我的代码：

import os 
import sys 
import sqlite3 
import time 
import datetime 
import minimalmodbus 
minimalmodbus.CLOSE_PORT_AFTER_EACH_CALL=True 

PORT_NAME   = '/com5' 
SLAVE1_ADDRESS  = 1 
SLAVE2_ADDRESS  = 2 
SLAVE3_ADDRESS  = 3 
BAUDRATE   = 9600 # baud (pretty much bits/s). Use 2400 or 38400 bits/s. 
TIMEOUT    = 0.4 # seconds. At least 0.2 seconds required for 2400 bits/s. 
MODE    = minimalmodbus.MODE_RTU 

sqlite_file = 'ModbusTable.db' 

instrument1 = minimalmodbus.Instrument(PORT_NAME, SLAVE1_ADDRESS, MODE) 
instrument1.serial.baudrate = BAUDRATE 
instrument1.serial.timeout = TIMEOUT 
instrument1.debug = False 
instrument1.precalculate_read_size = True 

instrument2 = minimalmodbus.Instrument(PORT_NAME, SLAVE2_ADDRESS, MODE) 
instrument2.serial.baudrate = BAUDRATE 
instrument2.serial.timeout = TIMEOUT 
instrument2.debug = False 
instrument2.precalculate_read_size = True 

instrument3 = minimalmodbus.Instrument(PORT_NAME, SLAVE3_ADDRESS, MODE) 
instrument3.serial.baudrate = BAUDRATE 
instrument3.serial.timeout = TIMEOUT 
instrument3.debug = False 
instrument3.precalculate_read_size = True 

print ('Okuyor') 


while 1: 

    # Connecting to the database file 
    conn = sqlite3.connect(sqlite_file) 
    c = conn.cursor() 

    try: 
     values1 = instrument1.read_registers(40005, 2) 
    except IOError: 
     print ('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(datetime.datetime.now())+"Failed to read from instrument1") 

    # C) Updates the pre-existing entry    
    c.execute("""UPDATE ModbusData SET SetPoint = ? ,ActualTemp = ? WHERE ID= ? """, 
     (values1[0],values1[1],1)) 

    time.sleep(0.5) 

    try: 
     values2 = instrument2.read_registers(40005, 2) 
    except IOError: 
     print ('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(datetime.datetime.now())+"Failed to read from instrument2") 

    # C) Updates the pre-existing entry    
    c.execute("""UPDATE ModbusData SET SetPoint = ? ,ActualTemp = ? WHERE ID= ? """, 
     (values2[0],values2[1],2)) 

    time.sleep(0.5) 

    try: 
     values3 = instrument3.read_registers(40005, 2) 
    except IOError: 
     print ('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(datetime.datetime.now())+"Failed to read from instrument3") 

    # C) Updates the pre-existing entry    
    c.execute("""UPDATE ModbusData SET SetPoint = ? ,ActualTemp = ? WHERE ID= ? """, 
     (values3[0],values3[1],3)) 

    time.sleep(0.5) 

    # Committing changes and closing the connection to the database file 
    conn.commit() 
    conn.close()

这里是恒温如何执行：