代码自用

 demo1 = master.execute(1, cst.READ_HOLDING_REGISTERS, 0, 9)

import modbus_tk
import modbus_tk.defines as cst
import modbus_tk.modbus_tcp as modbus_tcp

logger = modbus_tk.utils.create_logger("console")

if __name__ == "__main__":
    try:
        # 连接MODBUS TCP从机
        master = modbus_tcp.TcpMaster(host="127.0.0.1", port=502)
        master.set_timeout(5.0)
        logger.info("connected")
        # 读保持寄存器　
        demo1 = master.execute(1, cst.READ_HOLDING_REGISTERS, 0, 9)
        print(demo1)
        # 读输入寄存器
        # logger.info(master.execute(3, cst.READ_INPUT_REGISTERS, 0, 9, output_value=1))
        # # 读线圈寄存器
        # logger.info(master.execute(2, cst.READ_COILS, 0, 8))
        # logger.info(master.execute(2, cst.WRITE_SINGLE_COIL, 1, output_value=2))
        # # 读离散输入寄存器
        # logger.info(master.execute(4, cst.READ_DISCRETE_INPUTS, 0, 8))
        # 单个读写寄存器操作
        # 写寄存器地址为0的保持寄存器
        logger.info(master.execute(1, cst.WRITE_SINGLE_REGISTER, 0, output_value=25))
        logger.info(master.execute(1, cst.READ_HOLDING_REGISTERS, 0, 8))
        demo1 = master.execute(1, cst.READ_HOLDING_REGISTERS, 0, 9)
        print("demo1=",demo1)
        # 写寄存器地址为0的线圈寄存器，写入内容为0（位操作）
        logger.info(master.execute(2, cst.WRITE_SINGLE_COIL, 0, output_value=2))
        logger.info(master.execute(2, cst.READ_COILS, 0, 1))
        # # 多个寄存器读写操作
        # # 写寄存器起始地址为0的保持寄存器，操作寄存器个数为4
        logger.info(master.execute(1, cst.WRITE_MULTIPLE_REGISTERS, 0, output_value=[20, 21, 22, 23]))
        logger.info(master.execute(1, cst.READ_HOLDING_REGISTERS, 0, 4))
        # # 写寄存器起始地址为0的线圈寄存器
        logger.info(master.execute(2, cst.WRITE_MULTIPLE_COILS, 0, output_value=[0, 0, 0, 1]))
        logger.info(master.execute(2, cst.READ_COILS, 0, 4))
    except modbus_tk.modbus.ModbusError as e:
        logger.error("%s- Code=%d" % (e, e.get_exception_code()))

# import modbus_tk.defines
#
# #modbus exception codes  异常代码
# # 代码功能不合法
# ILLEGAL_FUNCTION = 1
# # 数据地址不合法
# ILLEGAL_DATA_ADDRESS = 2
# # 数据值不合法
# ILLEGAL_DATA_VALUE = 3
# # slave设备失败
# SLAVE_DEVICE_FAILURE = 4
# # 命令已收到
# COMMAND_ACKNOWLEDGE = 5
# # slave设备忙
# SLAVE_DEVICE_BUSY = 6
# # 内存奇偶校验差
# MEMORY_PARITY_ERROR = 8
#
# # supported modbus functions 功能代码
# # 读线圈
# READ_COILS = 1
# # 离散读输入
# READ_DISCRETE_INPUTS = 2
# # 读保持寄存器
# READ_HOLDING_REGISTERS = 3
# # 读输入寄存器
# READ_INPUT_REGISTERS = 4
# # 写单一线圈
# WRITE_SINGLE_COIL = 5
# # 写单一寄存器
# WRITE_SINGLE_REGISTER = 6
# # *读例外状态
# READ_EXCEPTION_STATUS = 7
# DIAGNOSTIC = 8
# # *报告slave的id
# REPORT_SLAVE_ID = 17
# # 写多个线圈
# WRITE_MULTIPLE_COILS = 15
# # 写多寄存器
# WRITE_MULTIPLE_REGISTERS = 16
# # *读写多个寄存器
# READ_WRITE_MULTIPLE_REGISTERS = 23
# # *设备信息
# DEVICE_INFO = 43
#
# # supported block types 支持的块类型
# # 线圈
# COILS = 1
# # 离散输入
# DISCRETE_INPUTS = 2
# # 保持寄存器
# HOLDING_REGISTERS = 3
# # 模拟量输入
# ANALOG_INPUTS = 4