是否有办法读取pymodbus内连接设备的数据？

Question

我有一个pymodbus异步服务器作为例子

#!/usr/bin/env python
"""
Pymodbus Asynchronous Server Example
--------------------------------------------------------------------------

The asynchronous server is a high performance implementation using the
twisted library as its backend.  This allows it to scale to many thousands
of nodes which can be helpful for testing monitoring software.
"""
# --------------------------------------------------------------------------- # 
# import the various server implementations
# --------------------------------------------------------------------------- # 
from pymodbus.server.asynchronous import StartTcpServer
from pymodbus.server.asynchronous import StartUdpServer
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,
                                  ModbusBinaryFramer)
from custom_message import CustomModbusRequest

# --------------------------------------------------------------------------- # 
# configure the service logging
# --------------------------------------------------------------------------- # 
import logging
FORMAT = ('%(asctime)-15s %(threadName)-15s'
          ' %(levelname)-8s %(module)-15s:%(lineno)-8s %(message)s')
logging.basicConfig(format=FORMAT)
log = logging.getLogger()
log.setLevel(logging.DEBUG)


def run_async_server():
    # ----------------------------------------------------------------------- # 
    # initialize your data store
    # ----------------------------------------------------------------------- # 
    # The datastores only respond to the addresses that they are initialized to
    # Therefore, if you initialize a DataBlock to addresses from 0x00 to 0xFF,
    # a request to 0x100 will respond with an invalid address exception.
    # This is because many devices exhibit this kind of behavior (but not all)
    #
    #     block = ModbusSequentialDataBlock(0x00, [0]*0xff)
    #
    # Continuing, you can choose to use a sequential or a sparse DataBlock in
    # your data context.  The difference is that the sequential has no gaps in
    # the data while the sparse can. Once again, there are devices that exhibit
    # both forms of behavior::
    #
    #     block = ModbusSparseDataBlock({0x00: 0, 0x05: 1})
    #     block = ModbusSequentialDataBlock(0x00, [0]*5)
    #
    # Alternately, you can use the factory methods to initialize the DataBlocks
    # or simply do not pass them to have them initialized to 0x00 on the full
    # address range::
    #
    #     store = ModbusSlaveContext(di = ModbusSequentialDataBlock.create())
    #     store = ModbusSlaveContext()
    #
    # Finally, you are allowed to use the same DataBlock reference for every
    # table or you you may use a seperate DataBlock for each table.
    # This depends if you would like functions to be able to access and modify
    # the same data or not::
    #
    #     block = ModbusSequentialDataBlock(0x00, [0]*0xff)
    #     store = ModbusSlaveContext(di=block, co=block, hr=block, ir=block)
    #
    # The server then makes use of a server context that allows the server to
    # respond with different slave contexts for different unit ids. By default
    # it will return the same context for every unit id supplied (broadcast
    # mode).
    # However, this can be overloaded by setting the single flag to False
    # and then supplying a dictionary of unit id to context mapping::
    #
    #     slaves  = {
    #         0x01: ModbusSlaveContext(...),
    #         0x02: ModbusSlaveContext(...),
    #         0x03: ModbusSlaveContext(...),
    #     }
    #     context = ModbusServerContext(slaves=slaves, single=False)
    #
    # The slave context can also be initialized in zero_mode which means that a
    # request to address(0-7) will map to the address (0-7). The default is
    # False which is based on section 4.4 of the specification, so address(0-7)
    # will map to (1-8)::
    #
    #     store = ModbusSlaveContext(..., zero_mode=True)
    # ----------------------------------------------------------------------- # 
    store = ModbusSlaveContext(
        di=ModbusSequentialDataBlock(0, [17]*100),
        co=ModbusSequentialDataBlock(0, [17]*100),
        hr=ModbusSequentialDataBlock(0, [17]*100),
        ir=ModbusSequentialDataBlock(0, [17]*100))
    store.register(CustomModbusRequest.function_code, 'cm',
                   ModbusSequentialDataBlock(0, [17] * 100))
    context = ModbusServerContext(slaves=store, single=True)

    # ----------------------------------------------------------------------- # 
    # 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/bashwork/pymodbus/'
    identity.ProductName = 'Pymodbus Server'
    identity.ModelName = 'Pymodbus Server'
    identity.MajorMinorRevision = '2.3.0'

    # ----------------------------------------------------------------------- # 
    # run the server you want
    # ----------------------------------------------------------------------- # 

    # TCP Server

    StartTcpServer(context, identity=identity, address=("localhost", 5020),
                   custom_functions=[CustomModbusRequest])

    # TCP Server with deferred reactor run

    # from twisted.internet import reactor
    # StartTcpServer(context, identity=identity, address=("localhost", 5020),
    #                defer_reactor_run=True)
    # reactor.run()

    # Server with RTU framer
    # StartTcpServer(context, identity=identity, address=("localhost", 5020),
    #                framer=ModbusRtuFramer)

    # UDP Server
    # StartUdpServer(context, identity=identity, address=("127.0.0.1", 5020))

    # RTU Server
    # StartSerialServer(context, identity=identity,
    #                   port='/dev/ttyp0', framer=ModbusRtuFramer)

    # ASCII Server
    # StartSerialServer(context, identity=identity,
    #                   port='/dev/ttyp0', framer=ModbusAsciiFramer)

    # Binary Server
    # StartSerialServer(context, identity=identity,
    #                   port='/dev/ttyp0', framer=ModbusBinaryFramer)


if __name__ == "__main__":
    run_async_server()

这是连接的设备内的命令，假定该设备正在向服务器传递数据

例如

modbusrtu -m tcp -a 1 -r 2 -p 502 192.168.1.2 1

假设上述modbusrtu命令通过tcp端口502将值1发送至modbus寄存器地址2，该地址位于地址为192.168.1.2的服务器中

那么，我应该如何在粘贴的python代码中获取数据呢？ 例如，在pymodbus服务器代码中，我想捕获寄存器地址2及其值1，并将它们存储在一个变量中，以便稍后使用

Answer 1

有几种方法，但您可以使用的一件事是从您创建的ModbusSlaveContext中删除值。例如，您可能可以执行类似store.store['h'].getValues(0, 1)的操作来读取地址0处保持寄存器的前8位。如果你想要一整行，读2。然后你就可以随心所欲地解码了