具有多个从设备上下文的 pymodbus Modbus 服务器实现 - 写入寄存器会覆盖所有从设备

Posted 2023-03-23

【中文标题】具有多个从设备上下文的 pymodbus Modbus 服务器实现 - 写入寄存器会覆盖所有从设备

【英文标题】：pymodbus Modbus Server implementation with multiple slave devices context - writing to a register overwrites to all slaves

【发布时间】：2020-09-08 22:48:17

【问题描述】：

我对简单的 pymodbus 服务器实现有疑问。从我在文档中读到的内容来看，这个实现应该有每个从设备唯一的从上下文，即写入设备 0x01，寄存器地址 1，应该是与设备 0x02，寄存器 1 不同的寄存器。

在我的情况下，写入寄存器 1 会写入所有从地址的寄存器 1。有人可以检查我的服务器代码，看看我是否遗漏了什么，或者澄清我是否理解 pymodbus 服务器应该如何在单个标志设置为 False 的情况下工作。

干杯。代码在这里：

#!/usr/bin/env python3
"""
Pymodbus Synchronous Server
--------------------------------------------------------------------------

This synced server is implemented using TCP, with multiple slave contexts
"""
# --------------------------------------------------------------------------- #
# import the various server implementations
# --------------------------------------------------------------------------- #
from pymodbus.server.sync import StartTcpServer

from pymodbus.device import ModbusDeviceIdentification
from pymodbus.datastore import ModbusSequentialDataBlock
from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext

def run_server():

    slaves = 

        0x01: ModbusSlaveContext(),
        0x02: ModbusSlaveContext()

    

    context = ModbusServerContext(slaves=slaves, single=False)

    # ----------------------------------------------------------------------- #
    # initialize the server information
    # ----------------------------------------------------------------------- #
    # If you don't set this or any fields, they are defaulted to empty strings.
    # ----------------------------------------------------------------------- #
    identity = ModbusDeviceIdentification()
    identity.VendorName = 'Pymodbus'
    identity.ProductCode = 'PM'
    identity.VendorUrl = 'http://github.com/riptideio/pymodbus/'
    identity.ProductName = 'Pymodbus Server'
    identity.ModelName = 'Pymodbus Server'
    identity.MajorMinorRevision = '2.3.0'

    # ----------------------------------------------------------------------- #
    # run the server
    # ----------------------------------------------------------------------- #
    StartTcpServer(context, identity=identity, address=("0.0.0.0", 5020))

if __name__ == "__main__":
    run_server()

【参考方案1】：

我在 RTU 服务器上遇到了类似的问题，并且代码和你的代码不太一样。

但对我来说，我没有在从属字典中创建单独的 ModbusSlaveContext 对象。但您的代码中并非如此。

我在这里分享我的代码，也许它可以帮助某人。

Python code:
    #!/usr/bin/env python
    """
    Pymodbus Server With Updating Thread
    --------------------------------------------------------------------------
    
    This is an example of having a background thread updating the
    context while the server is operating. This can also be done with
    a python thread::
    
        from threading import Thread
    
        thread = Thread(target=updating_writer, args=(context,))
        thread.start()
    """
    # --------------------------------------------------------------------------- #
    # import the modbus libraries we need
    # --------------------------------------------------------------------------- #
    from pymodbus.server.asynchronous import StartSerialServer
    from pymodbus.device import ModbusDeviceIdentification
    from pymodbus.datastore import ModbusSequentialDataBlock
    from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext
    from pymodbus.transaction import ModbusRtuFramer, ModbusAsciiFramer
    
    # --------------------------------------------------------------------------- #
    # import the payload builder
    # --------------------------------------------------------------------------- #
    from pymodbus.constants import Endian
    from pymodbus.payload import BinaryPayloadDecoder
    from pymodbus.payload import BinaryPayloadBuilder
    
    # --------------------------------------------------------------------------- #
    # import the twisted libraries we need
    # --------------------------------------------------------------------------- #
    from twisted.internet.task import LoopingCall
    
    # --------------------------------------------------------------------------- #
    # configure the service logging
    # --------------------------------------------------------------------------- #
    import logging
    logging.basicConfig()
    log = logging.getLogger()
    log.setLevel(logging.DEBUG)
    
    # --------------------------------------------------------------------------- #
    # define your callback process
    # --------------------------------------------------------------------------- #
    
    
    def updating_writer(a):
        """ A worker process that runs every so often and
        updates live values of the context. It should be noted
        that there is a race condition for the update.
    
        :param arguments: The input arguments to the call
        """
        context = a[0]
        register = 3
        
        #### Write to registers slave 1 ####
        slave_id = 0x01
        log.debug(f"::: Make payload to SLAVE=slave_id :::")
    
        # Total energy
        builder = BinaryPayloadBuilder(
            byteorder=Endian.Big,
            wordorder=Endian.Little
            )
        builder.add_32bit_int(20000)  # kWh Tot*10
        energy = builder.to_registers()
    
        # Phase 1 variables
        builder = BinaryPayloadBuilder(
            byteorder=Endian.Big,
            wordorder=Endian.Little
            )
        builder.add_32bit_int(4000)  # VL1L2*10
        builder.add_32bit_int(2300)  # VL1N*10
        builder.add_32bit_int(1000)  # AL1*1000
        builder.add_32bit_int(2300)  # kWL1*10
        phase1 = builder.to_registers()
    
        log.debug(f"::: Write registers to SLAVE=slave_id :::")
        context[slave_id].setValues(register, 0x0112, energy)
        context[slave_id].setValues(register, 0x011e, phase1)
        context[slave_id].setValues(register, 0x000b, [0x0155])
    
        #### Write to registers slave 100 ####
        slave_id = 0x64
        log.debug(f"::: Make payload to SLAVE=slave_id :::")
    
        # Total energy
        builder = BinaryPayloadBuilder(
            byteorder=Endian.Big,
            wordorder=Endian.Little
            )
        builder.add_32bit_int(20000)  # kWh Tot*10
        energy = builder.to_registers()
    
        # Phase 1 variables
        builder = BinaryPayloadBuilder(
            byteorder=Endian.Big,
            wordorder=Endian.Little
            )
        builder.add_32bit_int(4000)  # VL1L2*10
        builder.add_32bit_int(2300)  # VL1N*10
        builder.add_32bit_int(2000)  # AL1*1000
        builder.add_32bit_int(4600)  # kWL1*10
        phase1 = builder.to_registers()
    
        log.debug(f"::: Write registers to SLAVE=slave_id :::")
        context[slave_id].setValues(register, 0x0112, energy)
        context[slave_id].setValues(register, 0x011e, phase1)
        context[slave_id].setValues(register, 0x000b, [0x0155])
    
    
    def run_updating_server():
        # ----------------------------------------------------------------------- # 
        # initialize your data store
        # ----------------------------------------------------------------------- # 
    
        addresses = [1, 100]
        slaves = 
        for adress in addresses:
            store = ModbusSlaveContext(zero_mode=True)
            slaves.update(adress: store)
    
        context = ModbusServerContext(slaves=slaves, single=False)
    
        # ----------------------------------------------------------------------- # 
        # initialize the server information
        # ----------------------------------------------------------------------- # 
        identity = ModbusDeviceIdentification()
        identity.VendorName = 'pymodbus'
        identity.ProductCode = 'PM'
        identity.VendorUrl = 'http://github.com/bashwork/pymodbus/'
        identity.ProductName = 'pymodbus Server'
        identity.ModelName = 'pymodbus Server'
        identity.MajorMinorRevision = '2.3.0'
    
        # ----------------------------------------------------------------------- # 
        # run the server you want
        # ----------------------------------------------------------------------- # 
        time = 5  # 5 seconds delay
        loop = LoopingCall(f=updating_writer, a=(context,))
        loop.start(time, now=False) # initially delay by time
        StartSerialServer(
            context=context,
            framer=ModbusRtuFramer,
            identity=identity,
            port='/dev/ttyUSB0',
            timeout=0.0001,
            baudrate=9600,
            parity='N',
            bytesize=8,
            stopbits=1,
            ignore_missing_slaves=True)

if __name__ == "__main__":
    run_updating_server()