class ModbusUdpClientProtocol(protocol.DatagramProtocol, ModbusClientMixin):
'''
This represents the base modbus client protocol. All the application
layer code is deferred to a higher level wrapper.
'''
def __init__(self, framer=None, **kwargs):
''' Initializes the framer module
:param framer: The framer to use for the protocol
'''
self.framer = framer or ModbusSocketFramer(ClientDecoder())
if isinstance(self.framer, ModbusSocketFramer):
self.transaction = DictTransactionManager(self, **kwargs)
else: self.transaction = FifoTransactionManager(self, **kwargs)
def datagramReceived(self, data, params):
''' Get response, check for valid message, decode result
:param data: The data returned from the server
:param params: The host parameters sending the datagram
'''
_logger.debug("Datagram from: %s:%d" % params)
self.framer.processIncomingPacket(data, self._handleResponse)
def execute(self, request):
''' Starts the producer to send the next request to
consumer.write(Frame(request))
'''
request.transaction_id = self.transaction.getNextTID()
packet = self.framer.buildPacket(request)
self.transport.write(packet)
return self._buildResponse(request.transaction_id)
def _handleResponse(self, reply):
''' Handle the processed response and link to correct deferred
:param reply: The reply to process
'''
if reply is not None:
tid = reply.transaction_id
handler = self.transaction.getTransaction(tid)
if handler:
handler.callback(reply)
else: _logger.debug("Unrequested message: " + str(reply))
def _buildResponse(self, tid):
''' Helper method to return a deferred response
for the current request.
:param tid: The transaction identifier for this response
:returns: A defer linked to the latest request
'''
d = defer.Deferred()
self.transaction.addTransaction(d, tid)
return d
class ModbusClientProtocol(protocol.Protocol, ModbusClientMixin):
'''
This represents the base modbus client protocol. All the application
layer code is deferred to a higher level wrapper.
'''
def __init__(self, framer=None, **kwargs):
''' Initializes the framer module
:param framer: The framer to use for the protocol
'''
self._connected = False
self.framer = framer or ModbusSocketFramer(ClientDecoder())
if isinstance(self.framer, ModbusSocketFramer):
self.transaction = DictTransactionManager(self, **kwargs)
else: self.transaction = FifoTransactionManager(self, **kwargs)
def connectionMade(self):
''' Called upon a successful client connection.
'''
_logger.debug("Client connected to modbus server")
self._connected = True
def connectionLost(self, reason):
''' Called upon a client disconnect
:param reason: The reason for the disconnect
'''
_logger.debug("Client disconnected from modbus server: %s" % reason)
self._connected = False
for tid in self.transaction:
self.transaction.getTransaction(tid).errback(Failure(
ConnectionException('Connection lost during request')))
def dataReceived(self, data):
''' Get response, check for valid message, decode result
:param data: The data returned from the server
'''
self.framer.processIncomingPacket(data, self._handleResponse)
def execute(self, request):
''' Starts the producer to send the next request to
consumer.write(Frame(request))
'''
request.transaction_id = self.transaction.getNextTID()
packet = self.framer.buildPacket(request)
self.transport.write(packet)
return self._buildResponse(request.transaction_id)
def _handleResponse(self, reply):
''' Handle the processed response and link to correct deferred
:param reply: The reply to process
'''
if reply is not None:
tid = reply.transaction_id
handler = self.transaction.getTransaction(tid)
if handler:
handler.callback(reply)
else: _logger.debug("Unrequested message: " + str(reply))
def _buildResponse(self, tid):
''' Helper method to return a deferred response
for the current request.
:param tid: The transaction identifier for this response
:returns: A defer linked to the latest request
'''
if not self._connected:
return defer.fail(Failure(
ConnectionException('Client is not connected')))
d = defer.Deferred()
self.transaction.addTransaction(d, tid)
return d
