Question

我使用以下代码尝试以ModbusTCP从属设备发送数据：

import socket
import logging

from pymodbus.constants import Defaults
from pymodbus.factory import ClientDecoder
from pymodbus.exceptions import NotImplementedException, ParameterException
from pymodbus.exceptions import ConnectionException
from pymodbus.transaction import ModbusSocketFramer, ModbusBinaryFramer
from pymodbus.client.common import ModbusClientMixin



#------------------------------------------------------------------#
#Logging
#------------------------------------------------------------------#
_logger = logging.getLogger(__name__)

##------------------------------------------------------------------##
##The Synchronous Clients
##------------------------------------------------------------------##

class BaseModbusClient(ModbusClientMixin):

    def __init__(self, framer, **kwargs):

        self.framer = framer
        if isinstance(self.framer, ModbusSocketFramer):
            self.transaction = DictTrasactionManager(self, **kwargs)
        else: self.transcation = FitoTransactionManager(self, **kwargs)

    def connect(self):
        raise NotImplementedException("Method not implemented by derived class")

    def close(self):
        pass

    def _send(self, request):
        raise NotImplementedException("Method not implemented by derived class")

    def _recv(self, size):
        raise NotImplementedException("Method not implemented by derived class")

    def excecute(self, request=None):
        if not self.connect():
            raise ConnectionException("Failed to connect[%s]" % (self.__str__()))
        return self.transaction.execute(request)


    def __enter__(self):
         if not self.connect():
             raise ConnectionException("Failed to connect [%s]" % (self.__str__()))
         raise self

    def __exit__(self, klass, value, traceback):
         self.close()

    def __str__(self):
         return "Null Transport"

class ModbusTcpClient(BaseModbusClient):

    def __init__(self, host='192.168.3.2', port=Defaults.Port, framer=ModbusSocketFramer, **kwargs):
        self.host = host
        self.port = port
        self.source_address = kwargs.get('source_address', ('', 0))
        BaseModbusClient.__init__(self,framer(ClientDecoder()), **kwargs)

    def connect(self):
        if self.socket: return True
        try:
            address = (self.host, self.port)
            self.socket = socket.create_connection((self.host, self.port),          timeout=Defaults.Timeout, source_address=self.source_address)
    except socket.error, msg:
        _logger.error('Connection to (%s, %s) failed: %s' % (self.host, self.port, msg))
        self.close()

    def close(self):
        if self.socket:
            self.socket.close()
        self.socket = None

    def _send(self, request):
        if not self.socket:
            raise ConnectionException(self.__str__())
        if request:
            return self.socket.send(request)
        return 0

    def _recv(self, size):
        if not self.socket:
            raise ConnectionException(self.__str__())
        return self.socket.recv(size)

    def __str__(self):
        return "%s:%s" % (self.host, self.port)

现在我愿意开始并使用所有这些功能。我该如何开始？我应该只调用我需要的功能吗？我的意思是作为从站连接到主站并更改寄存器值。

感谢您的回答。

Answer 1

这应该让你开始。

from pymodbus.client.sync import ModbusTcpClient

#modbus connection
client = ModbusTcpClient('192.168.1.100')
connection = client.connect()

#read register
request = client.read_holding_registers(xxxx,3) #covert to float
result = request.registers

#write to register
client.write_registers(xxxx, [xxxx,xxxx,xxxx])

使用Modbus TCP客户端实现

1 个答案: