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Implementation of a Modbus Client Using Twisted
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--------------------------------------------------
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from twisted.internet import reactor, protocol
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from pymodbus.client.async import ModbusClientProtocol
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def printResult(result):
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print "Result: %d" % result.bits[0]
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result = client.write_coil(1, True)
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result.addCallback(printResult)
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reactor.callLater(1, reactor.stop)
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defer = protocol.ClientCreator(reactor, ModbusClientProtocol
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).connectTCP("localhost", 502)
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defer.addCallback(process)
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from twisted.internet import reactor
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from pymodbus.client.async import ModbusClientFactory
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from pymodbus.bit_read_message import ReadCoilsRequest
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requests = [ ReadCoilsRequest(0,99) ]
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p = reactor.connectTCP("localhost", 502, ModbusClientFactory(requests))
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factory = reactor.connectTCP("localhost", 502, ModbusClientFactory())
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if __name__ == "__main__":
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reactor.callLater(1, clientTest)
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reactor.callLater(1, process)
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from collections import deque
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from twisted.internet import reactor, defer, protocol
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from twisted.internet import defer, protocol
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from pymodbus.factory import ClientDecoder
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from pymodbus.exceptions import ConnectionException
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from pymodbus.transaction import ModbusSocketFramer
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from pymodbus.transaction import ModbusSocketFramer, ModbusTransactionManager
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from pymodbus.client.common import ModbusClientMixin
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#---------------------------------------------------------------------------#
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_logger = logging.getLogger(__name__)
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#---------------------------------------------------------------------------#
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# A manager for the transaction identifiers
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#---------------------------------------------------------------------------#
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_manager = ModbusTransactionManager()
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#---------------------------------------------------------------------------#
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# Connected Client Protocols
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#---------------------------------------------------------------------------#
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class ModbusClientProtocol(protocol.Protocol, ModbusClientMixin):
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This represents the base modbus client protocol. All the application
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layer code is deferred to a higher level wrapper.
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def __init__(self, framer=None):
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''' Initializes the framer module
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:param framer: The framer to use for the protocol
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self.framer = framer or ModbusSocketFramer(ClientDecoder())
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self._requests = deque() # link queue to tid
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self._requests = deque() # link queue to tid
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self._connected = False
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def connectionMade(self):
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:param data: The data returned from the server
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self.framer.processIncomingPacket(data, self._callback)
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def _callback(reply): # todo errback/callback
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self._requests.popleft().callback(reply)
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self.framer.processIncomingPacket(data, _callback)
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def execute(self, request):
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''' Starts the producer to send the next request to
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consumer.write(Frame(request))
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request.transaction_id = self.__getNextTID()
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request.transaction_id = _manager.getNextTID()
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#self.handler[request.transaction_id] = request
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packet = self.framer.buildPacket(request)
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self.transport.write(packet)
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return self._buildResponse()
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def _callback(self, reply):
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''' The callback to call with the response message
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:param reply: The decoded response message
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# todo errback/callback
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self._requests.popleft().callback(reply)
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def _buildResponse(self):
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''' Helper method to return a deferred response
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for the current request.
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self._requests.append(d)
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def __getNextTID(self):
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''' Used to retrieve the next transaction id
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:return: The next unique transaction id
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As the transaction identifier is represented with two
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bytes, the highest TID is 0xffff
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..todo:: Remove this and use the transaction manager
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tid = (ModbusClientProtocol.__tid + 1) & 0xffff
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ModbusClientProtocol.__tid = tid
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#----------------------------------------------------------------------#
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# Extra Functions
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#----------------------------------------------------------------------#
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# self.retry -= 1
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#---------------------------------------------------------------------------#
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# Not Connected Client Protocol
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#---------------------------------------------------------------------------#
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class ModbusUdpClientProtocol(protocol.DatagramProtocol, ModbusClientMixin):
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This represents the base modbus client protocol. All the application
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layer code is deferred to a higher level wrapper.
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def __init__(self, framer=None):
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''' Initializes the framer module
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:param framer: The framer to use for the protocol
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self.framer = framer or ModbusSocketFramer(ClientDecoder())
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self._requests = deque() # link queue to tid
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def datagramReceived(self, data, (host, port)):
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''' Get response, check for valid message, decode result
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:param data: The data returned from the server
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def _callback(reply): # todo errback/callback
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self._requests.popleft().callback(reply)
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_logger.debug("Datagram from: %s:%d" % (host, port))
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self.framer.processIncomingPacket(data, _callback)
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def execute(self, request):
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''' Starts the producer to send the next request to
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consumer.write(Frame(request))
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request.transaction_id = _manager.getNextTID()
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#self.handler[request.transaction_id] = request
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packet = self.framer.buildPacket(request)
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self.transport.write(packet)
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return self._buildResponse()
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def _buildResponse(self):
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''' Helper method to return a deferred response
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for the current request.
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:returns: A defer linked to the latest request
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self._requests.append(d)
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#---------------------------------------------------------------------------#
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# Client Factories
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#---------------------------------------------------------------------------#
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class ModbusClientFactory(protocol.ReconnectingClientFactory):
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protocol = ModbusClientProtocol
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#---------------------------------------------------------------------------#
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#---------------------------------------------------------------------------#
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# Exported symbols
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#---------------------------------------------------------------------------#
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#---------------------------------------------------------------------------#
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"ModbusClientProtocol", "ModbusClientFactory",
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"ModbusClientProtocol", "ModbusUdpClientProtocol",
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"ModbusClientFactory",
added
removed
pymodbus/client/async.py
