如何在pymodbus中分配保持寄存器？

Question

我在树莓派零上制作一个modbus服务器，将数据发送到modbus客户端/数据记录器。我正在尝试使用pymodbus，但在阅读文档时遇到了问题，我想知道是否有人可以向我演示如何为保持寄存器分配特定的值？我用Synchronous Server Example作为我的起点。我对Python还比较陌生，我真的需要了解这个代码/程序中发生了什么，所以如果需要进行更改，我可以这样做。任何帮助都将不胜感激。在

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

The synchronous server is implemented in pure python without any third
party libraries (unless you need to use the serial protocols which require
pyserial). This is helpful in constrained or old environments where using
twisted is just not feasible. What follows is an example of its use:
"""
# --------------------------------------------------------------------------- #
# import the various server implementations
# --------------------------------------------------------------------------- #
from pymodbus.server.sync import StartTcpServer
from pymodbus.server.sync import StartUdpServer
from pymodbus.server.sync import StartSerialServer

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

from pymodbus.transaction import ModbusRtuFramer, ModbusBinaryFramer
# --------------------------------------------------------------------------- #
# 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_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 of 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 may use a separate 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))

    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/riptideio/pymodbus/'
    identity.ProductName = 'Pymodbus Server'
    identity.ModelName = 'Pymodbus Server'
    identity.MajorMinorRevision = '1.5'

    # ----------------------------------------------------------------------- #
    # run the server you want
    # ----------------------------------------------------------------------- #
    # Tcp:
    StartTcpServer(context, identity=identity, address=("localhost", 5020))

    # TCP with different framer
    # StartTcpServer(context, identity=identity,
    #                framer=ModbusRtuFramer, address=("0.0.0.0", 5020))

    # Udp:
    # StartUdpServer(context, identity=identity, address=("0.0.0.0", 5020))

    # Ascii:
    # StartSerialServer(context, identity=identity,
    #                    port='/dev/ttyp0', timeout=1)

    # RTU:
    # StartSerialServer(context, framer=ModbusRtuFramer, identity=identity,
    #                   port='/dev/ttyp0', timeout=.005, baudrate=9600)

    # Binary
    # StartSerialServer(context,
    #                   identity=identity,
    #                   framer=ModbusBinaryFramer,
    #                   port='/dev/ttyp0',
    #                   timeout=1)


if __name__ == "__main__":
    run_server()

看起来我使用了错误的服务器，应该使用回调服务器，但我仍然不确定如何将数据分配给由本地传感器/设备读入的输入/保持寄存器。这是Call back Server:的代码

^{pr2}$

再次感谢任何帮助。在

Answer 1

from pymodbus.client.sync import ModbusTcpClient
address = 2 #register address
value = 12 #new value
unitId = 1
host = "127.0.0.1"
port = 502

client = ModbusTcpClient(host, port)
client.connect()
client.write_register(address,value,unit=unitId)

这里有两个基本功能代码（读、写线圈/保持寄存器）：https://github.com/omergunal/Modbus-Web-Interface/blob/master/app.py