Modbus主机无法更新第二个客户端编写的数据。

Question

我们一直在努力将传送带纳入我们的应用程序。供应商告诉我们，他们有一个modbus主机，每10 us更新一次值，我们应该在某个IP/端口上有一个从服务器。经过调查，我们发现我们需要分拆一个modbus tcp服务器。我们试图利用：

PyModbusTCP

from pyModbusTCP.server import ModbusServer
server = ModbusServer(host="", port=502)
server.start()

pymodbus：

import logging
import asyncio

from pymodbus.version import version
from pymodbus.server.async_io import StartTcpServer

from pymodbus.device import ModbusDeviceIdentification
from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext
from pymodbus.datastore import ModbusSequentialDataBlock
import os
BASE_DIR = os.path.dirname(os.path.abspath(__file__))


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


async def run_server(host: str = '10.0.0.2',
                     port: int = 502,
                     debug: bool = True):
    """Run server."""
    logger.debug(f'Starting server at host="{host}", port="{port}"')
    store = ModbusSlaveContext(
        di=ModbusSequentialDataBlock.create(),
        co=ModbusSequentialDataBlock.create(),
        hr=ModbusSequentialDataBlock.create(),
        ir=ModbusSequentialDataBlock.create(),
        zero_mode=True,
    )

    context = ModbusServerContext(slaves=store, single=True)

    server = await StartTcpServer(
        context,
        address=(host, port),  # nosec
        allow_reuse_address=True,
        defer_start=True,
        console=debug,
    )

    asyncio.get_event_loop().call_later(20, lambda: server.serve_forever)
    await server.serve_forever()


if __name__ == '__main__':
    host: str = ""
    port: int = 502
    debug: bool = 1

    asyncio.run(run_server(host, port, debug))

对他们两人来说：

• 主程序可以编写值
• 第二个客户端(来自不同的进程)可以编写值
• ，第二个客户端可以从主服务器读取更新的值以及它早先编写的

值。

但是，第二个客户端编写的值不会在主服务器中得到更新。事实上，供应商说他们根本看不到任何值，尽管他们可以看到modbus连接是活动的。

在从第二个客户端写入时，来自服务器(从服务器)的日志有一个错误，我们不知道它是什么：

2022-06-22 12:38:11,796 MainThread      DEBUG    selector_events:59       Using selector: EpollSelector
2022-06-22 12:38:11,796 MainThread      DEBUG    server         :93       Starting server at host="", port="503"
2022-06-22 12:38:19,008 MainThread      DEBUG    async_io       :76       Socket [10.42.0.149:503] opened
2022-06-22 12:38:19,008 MainThread      DEBUG    async_io       :282      TCP client connection established [10.42.0.148:60480]
2022-06-22 12:38:19,008 MainThread      DEBUG    async_io       :76       Socket [10.42.0.149:503] opened
2022-06-22 12:38:19,008 MainThread      DEBUG    async_io       :282      TCP client connection established [10.42.0.148:60478]
2022-06-22 12:38:19,008 MainThread      DEBUG    async_io       :168      Handling data: 0x4d 0x4b 0x0 0x0 0x0 0x6 0x1 0x3 0x60 0x0 0x0 0x1
2022-06-22 12:38:19,008 MainThread      DEBUG    socket_framer  :147      Processing: 0x4d 0x4b 0x0 0x0 0x0 0x6 0x1 0x3 0x60 0x0 0x0 0x1
2022-06-22 12:38:19,008 MainThread      DEBUG    factory        :137      Factory Request[ReadHoldingRegistersRequest: 3]
2022-06-22 12:38:19,008 MainThread      DEBUG    context        :63       validate: fc-[3] address-24576: count-1
2022-06-22 12:38:19,008 MainThread      DEBUG    context        :77       getValues fc-[3] address-24576: count-1
2022-06-22 12:38:19,009 MainThread      DEBUG    async_io       :233      send: [ReadHoldingRegistersResponse (1)]- b'4d4b000000050103020000'
2022-06-22 12:38:19,009 MainThread      DEBUG    async_io       :76       Socket [10.42.0.149:503] opened
2022-06-22 12:38:19,009 MainThread      DEBUG    async_io       :282      TCP client connection established [10.42.0.148:60482]
2022-06-22 12:38:19,009 MainThread      DEBUG    async_io       :76       Socket [10.42.0.149:503] opened
2022-06-22 12:38:19,009 MainThread      DEBUG    async_io       :282      TCP client connection established [10.42.0.148:60484]
2022-06-22 12:38:19,009 MainThread      DEBUG    async_io       :168      Handling data: 0xd2 0x19 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1
2022-06-22 12:38:19,009 MainThread      DEBUG    socket_framer  :147      Processing: 0xd2 0x19 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1
2022-06-22 12:38:19,009 MainThread      DEBUG    factory        :137      Factory Request[ReadCoilsRequest: 1]
2022-06-22 12:38:19,010 MainThread      DEBUG    context        :63       validate: fc-[1] address-16384: count-1
2022-06-22 12:38:19,010 MainThread      DEBUG    context        :77       getValues fc-[1] address-16384: count-1
2022-06-22 12:38:19,010 MainThread      DEBUG    async_io       :233      send: [ReadCoilsResponse(1)]- b'd2190000000401010100'
2022-06-22 12:38:19,012 MainThread      DEBUG    async_io       :168      Handling data: 0xec 0x78 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x1 0x0 0x1
2022-06-22 12:38:19,012 MainThread      DEBUG    socket_framer  :147      Processing: 0xec 0x78 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x1 0x0 0x1
2022-06-22 12:38:19,012 MainThread      DEBUG    factory        :137      Factory Request[ReadCoilsRequest: 1]
2022-06-22 12:38:19,012 MainThread      DEBUG    context        :63       validate: fc-[1] address-16385: count-1
2022-06-22 12:38:19,012 MainThread      DEBUG    context        :77       getValues fc-[1] address-16385: count-1
2022-06-22 12:38:19,012 MainThread      DEBUG    async_io       :233      send: [ReadCoilsResponse(1)]- b'ec780000000401010100'
2022-06-22 12:38:20,011 MainThread      DEBUG    async_io       :168      Handling data: 0xf 0x14 0x0 0x0 0x0 0x6 0x1 0x5 0x0 0x0 0x0 0x0
2022-06-22 12:38:20,011 MainThread      DEBUG    socket_framer  :147      Processing: 0xf 0x14 0x0 0x0 0x0 0x6 0x1 0x5 0x0 0x0 0x0 0x0
2022-06-22 12:38:20,011 MainThread      DEBUG    factory        :137      Factory Request[WriteSingleCoilRequest: 5]
2022-06-22 12:38:20,011 MainThread      DEBUG    context        :63       validate: fc-[5] address-0: count-1
2022-06-22 12:38:20,011 MainThread      DEBUG    context        :90       setValues[5] 0:1
2022-06-22 12:38:20,011 MainThread      DEBUG    context        :77       getValues fc-[5] address-0: count-1
2022-06-22 12:38:20,011 MainThread      DEBUG    async_io       :233      send: [WriteCoilResponse(0) => 0]- b'0f1400000006010500000000'
2022-06-22 12:38:20,012 MainThread      DEBUG    async_io       :168      Handling data: 0x1a 0x83 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1
2022-06-22 12:38:20,012 MainThread      DEBUG    socket_framer  :147      Processing: 0x1a 0x83 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1
2022-06-22 12:38:20,012 MainThread      DEBUG    factory        :137      Factory Request[ReadCoilsRequest: 1]
2022-06-22 12:38:20,012 MainThread      DEBUG    context        :63       validate: fc-[1] address-16384: count-1
2022-06-22 12:38:20,012 MainThread      DEBUG    context        :77       getValues fc-[1] address-16384: count-1
2022-06-22 12:38:20,013 MainThread      DEBUG    async_io       :233      send: [ReadCoilsResponse(1)]- b'1a830000000401010100'
2022-06-22 12:38:21,014 MainThread      DEBUG    async_io       :168      Handling data: 0xd1 0x28 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1
2022-06-22 12:38:21,014 MainThread      DEBUG    socket_framer  :147      Processing: 0xd1 0x28 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1
2022-06-22 12:38:21,014 MainThread      DEBUG    factory        :137      Factory Request[ReadCoilsRequest: 1]
2022-06-22 12:38:21,014 MainThread      DEBUG    context        :63       validate: fc-[1] address-16384: count-1
2022-06-22 12:38:21,014 MainThread      DEBUG    context        :77       getValues fc-[1] address-16384: count-1
2022-06-22 12:38:21,014 MainThread      DEBUG    async_io       :233      send: [ReadCoilsResponse(1)]- b'd1280000000401010100'
2022-06-22 12:38:21,015 MainThread      DEBUG    async_io       :76       Socket [10.42.0.149:503] opened
2022-06-22 12:38:21,015 MainThread      DEBUG    async_io       :282      TCP client connection established [10.42.0.148:60512]
2022-06-22 12:38:21,015 MainThread      DEBUG    async_io       :168      Handling data: 0x80 0xb6 0x0 0x0 0x0 0x6 0x1 0x5 0x0 0x0 0xff 0x0
2022-06-22 12:38:21,015 MainThread      DEBUG    socket_framer  :147      Processing: 0x80 0xb6 0x0 0x0 0x0 0x6 0x1 0x5 0x0 0x0 0xff 0x0
2022-06-22 12:38:21,015 MainThread      DEBUG    factory        :137      Factory Request[WriteSingleCoilRequest: 5]
2022-06-22 12:38:21,015 MainThread      DEBUG    context        :63       validate: fc-[5] address-0: count-1
2022-06-22 12:38:21,015 MainThread      DEBUG    context        :90       setValues[5] 0:1
2022-06-22 12:38:21,016 MainThread      DEBUG    context        :77       getValues fc-[5] address-0: count-1
2022-06-22 12:38:21,016 MainThread      DEBUG    async_io       :233      send: [WriteCoilResponse(0) => 1]- b'80b60000000601050000ff00'
2022-06-22 12:38:21,016 MainThread      ERROR    async_io       :54       Handler for stream [10.42.0.148:60512] has been canceled
2022-06-22 12:38:21,016 MainThread      DEBUG    async_io       :291      TCP client disconnected [10.42.0.148:60512]
2022-06-22 12:38:21,016 MainThread      ERROR    async_io       :54       Handler for stream [10.42.0.148:60512] has been canceled
2022-06-22 12:38:22,016 MainThread      DEBUG    async_io       :168      Handling data: 0xd1 0x8 0x0 0x0 0x0 0x6 0x1 0x3 0x60 0x0 0x0 0x1
2022-06-22 12:38:22,016 MainThread      DEBUG    socket_framer  :147      Processing: 0xd1 0x8 0x0 0x0 0x0 0x6 0x1 0x3 0x60 0x0 0x0 0x1
2022-06-22 12:38:22,016 MainThread      DEBUG    factory        :137      Factory Request[ReadHoldingRegistersRequest: 3]
2022-06-22 12:38:22,016 MainThread      DEBUG    context        :63       validate: fc-[3] address-24576: count-1
2022-06-22 12:38:22,016 MainThread      DEBUG    context        :77       getValues fc-[3] address-24576: count-1
2022-06-22 12:38:22,016 MainThread      DEBUG    async_io       :233      send: [ReadHoldingRegistersResponse (1)]- b'd108000000050103020000'
2022-06-22 12:38:22,016 MainThread      DEBUG    async_io       :168      Handling data: 0xe4 0x7f 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x1 0x0 0x1
2022-06-22 12:38:22,016 MainThread      DEBUG    socket_framer  :147      Processing: 0xe4 0x7f 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x1 0x0 0x1
2022-06-22 12:38:22,016 MainThread      DEBUG    factory        :137      Factory Request[ReadCoilsRequest: 1]
2022-06-22 12:38:22,017 MainThread      DEBUG    context        :63       validate: fc-[1] address-16385: count-1
2022-06-22 12:38:22,017 MainThread      DEBUG    context        :77       getValues fc-[1] address-16385: count-1
2022-06-22 12:38:22,017 MainThread      DEBUG    async_io       :233      send: [ReadCoilsResponse(1)]- b'e47f0000000401010100'
2022-06-22 12:38:22,017 MainThread      DEBUG    async_io       :168      Handling data: 0x4f 0x95 0x0 0x0 0x0 0x6 0x1 0x1 0x40 0x0 0x0 0x1

任何帮助都将不胜感激！提前感谢！

Answer 1

这个问题现在已经解决了。问题是供应商已经设置了硬件连接，所以他们使用不同的功能来读取：

​

​

而他们使用的是FC2s和FC4s等，因此主程序无法读取我们的值。

Answer 2

从您的描述中，我们并不清楚问题是什么(正如您所说的，“有一个错误，我们不知道它是什么”)。来自服务器的日志不会显示任何错误，但它们确实显示了一些可能解释您所看到的内容的内容。

编写单线圈请求是：0f 14 00 00 00 06 01 05 00 00 00 00。这是将线圈01 (物理00)的值设置为off的请求。

然后我们看到一个读取请求1a 83 00 00 00 06 01 01 40 00 00 01。这是要求从线圈0x4001 (物理0x4000)开始的1个线圈。

因此，您似乎没有访问相同的线圈(写入0x01，而是从0x4001读取)(因此，值没有发生变化也就不足为奇了)。请注意，我只快速扫描了日志，因此可能遗漏了一些内容。