Python读取modbus RTU协议

下载modbus_tk库

pip3 install modbus_tk

execute主要函数

参考文章Python玩转modbus

软件模拟

• vspd
• modbus slave

虚拟COM1和COM2

modbus slave连接COM2口

更改从机数据

Python读取

import serial
from modbus_tk import defines as cst
from modbus_tk import modbus_rtu

try:
    port = 'COM1'  # 串口号
    baud = 115200  # 波特率
    ser = serial.Serial(port, baud, bytesize=8, parity='N', stopbits=1, timeout=0.5)
    flag = ser.isOpen()
    if flag:
        print("Succeed to open port")
        master = modbus_rtu.RtuMaster(ser)
        master.set_timeout(1.0)

        read_tuple = master.execute(1, cst.READ_HOLDING_REGISTERS, 0x00, 10)
        print(read_tuple)
        read_tuple_hex = [hex(i) for i in read_tuple]
        print(read_tuple_hex)

except Exception as exc:
    print("Failed to open port")

输出

Succeed to open port
(0, 0, 1546, 0, 20, 0, 0, 100, 0, 36)
['0x0', '0x0', '0x60a', '0x0', '0x14', '0x0', '0x0', '0x64', '0x0', '0x24']