def _sendPacket(self, message, callback):
"""
Sends packets on the bus with 3.5char delay between frames
:param message: Message to be sent over the bus
:return:
"""
@gen.coroutine
def sleep(timeout):
yield gen.sleep(timeout)
try:
waiting = self.stream.connection.in_waiting
if waiting:
result = self.stream.connection.read(waiting)
LOGGER.info("Cleanup recv buffer before send: " +
hexlify_packets(result))
except OSError as e:
self.transaction.getTransaction(
message.transaction_id).set_exception(ModbusIOException(e))
return
start = time.time()
if self.last_frame_end:
waittime = self.last_frame_end + self.silent_interval - start
if waittime > 0:
LOGGER.debug("Waiting for 3.5 char before next send - %f ms",
waittime)
sleep(waittime)
self.state = ModbusTransactionState.SENDING
LOGGER.debug("send: " + hexlify_packets(message))
self.stream.write(message, callback)
def _transact(self, packet, response_length, full=False):
"""
Does a Write and Read transaction
:param packet: packet to be sent
:param response_length: Expected response length
:param full: the target device was notorious for its no response. Dont
waste time this time by partial querying
:return: response
"""
last_exception = None
try:
self.client.connect()
packet = self.client.framer.buildPacket(packet)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("SEND: " + hexlify_packets(packet))
size = self._send(packet)
if size:
_logger.debug("Changing transaction state from 'SENDING' "
"to 'WAITING FOR REPLY'")
self.client.state = ModbusTransactionState.WAITING_FOR_REPLY
result = self._recv(response_length, full)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("RECV: " + hexlify_packets(result))
except (socket.error, ModbusIOException,
InvalidMessageReceivedException) as msg:
self.client.close()
_logger.debug("Transaction failed. (%s) " % msg)
last_exception = msg
result = b''
return result, last_exception
def _transact(self, packet, response_length, full=False):
"""
Does a Write and Read transaction
:param packet: packet to be sent
:param response_length: Expected response length
:param full: the target device was notorious for its no response. Dont
waste time this time by partial querying
:return: response
"""
last_exception = None
try:
self.client.connect()
packet = self.client.framer.buildPacket(packet)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("SEND: " + hexlify_packets(packet))
size = self._send(packet)
if size:
_logger.debug("Changing transaction state from 'SENDING' "
"to 'WAITING FOR REPLY'")
self.client.state = ModbusTransactionState.WAITING_FOR_REPLY
result = self._recv(response_length, full)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("RECV: " + hexlify_packets(result))
except (socket.error, ModbusIOException,
InvalidMessageReceivedException) as msg:
self.client.close()
_logger.debug("Transaction failed. (%s) " % msg)
last_exception = msg
result = b''
return result, last_exception
def _dump(self, data, direction):
fd = self._debugfd if self._debugfd else sys.stdout
try:
fd.write(hexlify_packets(data))
except Exception as e:
self._logger.debug(hexlify_packets(data))
self._logger.exception(e)
def _send(self, request):
""" Sends data on the underlying socket
If receive buffer still holds some data then flush it.
Sleep if last send finished less than 3.5 character
times ago.
:param request: The encoded request to send
:return: The number of bytes written
"""
if not self.socket:
raise ConnectionException(self.__str__())
if request:
try:
waitingbytes = self._in_waiting()
if waitingbytes:
result = self.socket.read(waitingbytes)
if self.state == ModbusTransactionState.RETRYING:
_logger.debug("Sending available data in recv "
"buffer {}".format(
hexlify_packets(result)))
return result
if _logger.isEnabledFor(logging.WARNING):
_logger.warning("Cleanup recv buffer before "
"send: " + hexlify_packets(result))
except NotImplementedError:
pass
if self.state != ModbusTransactionState.SENDING:
_logger.debug("New Transaction state 'SENDING'")
self.state = ModbusTransactionState.SENDING
size = self.socket.write(request)
return size
return 0
def _dump(self, data, direction):
fd = self._debugfd if self._debugfd else sys.stdout
try:
fd.write(hexlify_packets(data))
except Exception as e:
self._logger.debug(hexlify_packets(data))
self._logger.exception(e)
def _transact(self, packet, response_length, full=False, broadcast=False):
"""
Does a Write and Read transaction
:param packet: packet to be sent
:param response_length: Expected response length
:param full: the target device was notorious for its no response. Dont
waste time this time by partial querying
:return: response
"""
last_exception = None
try:
self.client.connect()
packet = self.client.framer.buildPacket(packet)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("SEND: " + hexlify_packets(packet))
size = self._send(packet)
if isinstance(
size, bytes
) and self.client.state == ModbusTransactionState.RETRYING:
_logger.debug("Changing transaction state from "
"'RETRYING' to 'PROCESSING REPLY'")
self.client.state = ModbusTransactionState.PROCESSING_REPLY
return size, None
if broadcast:
if size:
_logger.debug("Changing transaction state from 'SENDING' "
"to 'TRANSACTION_COMPLETE'")
self.client.state = ModbusTransactionState.TRANSACTION_COMPLETE
return b'', None
if size:
_logger.debug("Changing transaction state from 'SENDING' "
"to 'WAITING FOR REPLY'")
self.client.state = ModbusTransactionState.WAITING_FOR_REPLY
if hasattr(self.client, "handle_local_echo"
) and self.client.handle_local_echo is True:
local_echo_packet = self._recv(size, full)
if local_echo_packet != packet:
return b'', "Wrong local echo"
result = self._recv(response_length, full)
# result2 = self._recv(response_length, full)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("RECV: " + hexlify_packets(result))
except (socket.error, ModbusIOException,
InvalidMessageReceivedException) as msg:
if self.reset_socket:
self.client.close()
_logger.debug("Transaction failed. (%s) " % msg)
last_exception = msg
result = b''
return result, last_exception
def getRawFrame(self):
"""
Returns the complete buffer
"""
_logger.debug("Getting Raw Frame - "
"{}".format(hexlify_packets(self._buffer)))
return self._buffer
def _send(self, request):
""" Sends data on the underlying socket
If receive buffer still holds some data then flush it.
Sleep if last send finished less than 3.5 character
times ago.
:param request: The encoded request to send
:return: The number of bytes written
"""
if not self.socket:
raise ConnectionException(self.__str__())
if request:
try:
waitingbytes = self._in_waiting()
if waitingbytes:
result = self.socket.read(waitingbytes)
if _logger.isEnabledFor(logging.WARNING):
_logger.warning("Cleanup recv buffer before "
"send: " + hexlify_packets(result))
except NotImplementedError:
pass
size = self.socket.write(request)
return size
return 0
def execute(self, request=None):
"""
Executes a transaction
:param request: Request to be written on to the bus
:return:
"""
request.transaction_id = self.transaction.getNextTID()
def callback(*args):
LOGGER.debug("in callback - {}".format(request.transaction_id))
while True:
waiting = self.stream.connection.in_waiting
if waiting:
data = self.stream.connection.read(waiting)
LOGGER.debug("recv: " + hexlify_packets(data))
unit = self.framer.decode_data(data).get("uid", 0)
self.framer.processIncomingPacket(
data,
self._handle_response,
unit,
tid=request.transaction_id)
break
packet = self.framer.buildPacket(request)
LOGGER.debug("send: " + hexlify_packets(packet))
self.stream.write(packet, callback=callback)
f = self._build_response(request.transaction_id)
return f
def _on_receive(fd, events):
LOGGER.debug("_on_receive: %s, %s", fd, events)
try:
waiting = self.stream.connection.in_waiting
if waiting:
LOGGER.debug("waiting = %d", waiting)
data = self.stream.connection.read(waiting)
LOGGER.debug(
"recv: " + hexlify_packets(data))
except OSError as ex:
_clear_timer()
self.close()
self.transaction.getTransaction(request.transaction_id).set_exception(ModbusIOException(ex))
return
self.framer.addToFrame(data)
# check if we have regular frame or modbus exception
fcode = self.framer.decode_data(self.framer.getRawFrame()).get("fcode", 0)
if fcode and (
(fcode > 0x80 and len(self.framer.getRawFrame()) == exception_response_length)
or
(len(self.framer.getRawFrame()) == expected_response_length)
):
_clear_timer()
self.io_loop.remove_handler(fd)
self.state = ModbusTransactionState.IDLE
self.framer.processIncomingPacket(
b'', # already sent via addToFrame()
self._handle_response,
0, # don't care for `single=True`
single=True,
tid=request.transaction_id
)
def handle(self, event):
reset_frame = False
try:
units = self.context.slaves()
if isinstance(event, QuicEvent):
# addr is populated when talking over UDP
data = event.data
else:
print("event is none")
return
if not isinstance(units, (list, tuple)):
units = [units]
# if broadcast is enabled make sure to
# process requests to address 0
if self.broadcast_enable: # pragma: no cover
if 0 not in units:
units.append(0)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
single = self.context.single
self.framer.processIncomingPacket(
data=data,
callback=lambda x: self.execute(x, event),
unit=units,
single=single)
finally:
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def getRawFrame(self):
"""
Returns the complete buffer
"""
_logger.debug("Getting Raw Frame - "
"{}".format(hexlify_packets(self._buffer)))
return self._buffer
def handle(self):
""" Callback when we receive any data
"""
reset_frame = False
while self.running:
try:
data, self.socket = self.request
if not data:
self.running = False
data = b''
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
# if not self.server.control.ListenOnly:
units = self.server.context.slaves()
single = self.server.context.single
self.framer.processIncomingPacket(data, self.execute,
units, single=single)
except socket.timeout: pass
except socket.error as msg:
_logger.error("Socket error occurred %s" % msg)
self.running = False
reset_frame = True
except Exception as msg:
_logger.error(msg)
self.running = False
reset_frame = True
finally:
# Reset data after processing
self.request = (None, self.socket)
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def handle(self):
""" Callback when we receive any data
"""
reset_frame = False
while self.running:
try:
data, self.socket = self.request
if not data:
self.running = False
data = b''
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
# if not self.server.control.ListenOnly:
units = self.server.context.slaves()
single = self.server.context.single
self.framer.processIncomingPacket(data, self.execute,
units, single=single)
except socket.timeout:
pass
except socket.error as msg:
_logger.error("Socket error occurred %s" % msg)
self.running = False
reset_frame = True
except Exception as msg:
_logger.error(msg)
self.running = False
reset_frame = True
finally:
# Reset data after processing
self.request = (None, self.socket)
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def _dataReceived(self, data):
''' Get response, check for valid message, decode result
:param data: The data returned from the server
'''
_logger.debug("recv: " + hexlify_packets(data))
unit = self.framer.decode_data(data).get("unit", 0)
self.framer.processIncomingPacket(data, self._handleResponse, unit=unit)
def handle(self):
"""Callback when we receive any data, until self.running becomes False.
Blocks indefinitely awaiting data. If shutdown is required, then the
global socket.settimeout(<seconds>) may be used, to allow timely
checking of self.running. However, since this also affects socket
connects, if there are outgoing socket connections used in the same
program, then these will be prevented, if the specfied timeout is too
short. Hence, this is unreliable.
To respond to Modbus...Server.server_close() (which clears each
handler's self.running), derive from this class to provide an
alternative handler that awakens from time to time when no input is
available and checks self.running.
Use Modbus...Server( handler=... ) keyword to supply the alternative
request handler class.
"""
reset_frame = False
while self.running:
try:
units = self.server.context.slaves()
data = self.request.recv(1024)
if not data:
self.running = False
else:
if not isinstance(units, (list, tuple)):
units = [units]
# if broadcast is enabled make sure to
# process requests to address 0
if self.server.broadcast_enable:
if 0 not in units:
units.append(0)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
single = self.server.context.single
self.framer.processIncomingPacket(data,
self.execute,
units,
single=single)
except socket.timeout as msg:
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("Socket timeout occurred %s", msg)
reset_frame = True
except socket.error as msg:
_logger.error("Socket error occurred %s" % msg)
self.running = False
except:
_logger.error("Socket exception occurred "
"%s" % traceback.format_exc())
self.running = False
reset_frame = True
finally:
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def _execute(self, request, **kwargs):
"""
Starts the producer to send the next request to
consumer.write(Frame(request))
"""
request.transaction_id = self.transaction.getNextTID()
packet = self.framer.buildPacket(request)
_logger.debug("send: " + hexlify_packets(packet))
self.write_transport(packet)
return self._buildResponse(request.transaction_id)
def handle(self):
"""Callback when we receive any data, until self.running becomes False.
Blocks indefinitely awaiting data. If shutdown is required, then the
global socket.settimeout(<seconds>) may be used, to allow timely
checking of self.running. However, since this also affects socket
connects, if there are outgoing socket connections used in the same
program, then these will be prevented, if the specfied timeout is too
short. Hence, this is unreliable.
To respond to Modbus...Server.server_close() (which clears each
handler's self.running), derive from this class to provide an
alternative handler that awakens from time to time when no input is
available and checks self.running.
Use Modbus...Server( handler=... ) keyword to supply the alternative
request handler class.
"""
reset_frame = False
while self.running:
try:
units = self.server.context.slaves()
data = self.request.recv(1024)
if not data:
self.running = False
else:
if not isinstance(units, (list, tuple)):
units = [units]
# if broadcast is enabled make sure to
# process requests to address 0
if self.server.broadcast_enable:
if 0 not in units:
units.append(0)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
single = self.server.context.single
self.framer.processIncomingPacket(data, self.execute, units,
single=single)
except socket.timeout as msg:
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("Socket timeout occurred %s", msg)
reset_frame = True
except socket.error as msg:
_logger.error("Socket error occurred %s" % msg)
self.running = False
except:
_logger.error("Socket exception occurred "
"%s" % traceback.format_exc() )
self.running = False
reset_frame = True
finally:
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def datagramReceived(self, data, addr):
""" Callback when we receive any data
:param data: The data sent by the client
"""
_logger.debug("Client Connected [%s]" % addr)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("Datagram Received: "+ hexlify_packets(data))
if not self.control.ListenOnly:
continuation = lambda request: self._execute(request, addr)
self.framer.processIncomingPacket(data, continuation)
def execute(self, request=None):
"""
Executes a transaction
:param request:
:return:
"""
request.transaction_id = self.transaction.getNextTID()
packet = self.framer.buildPacket(request)
LOGGER.debug("send: " + hexlify_packets(packet))
self.stream.write(packet)
return self._build_response(request.transaction_id)
def datagramReceived(self, data, addr):
""" Callback when we receive any data
:param data: The data sent by the client
"""
_logger.debug("Client Connected [%s]" % addr)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("Datagram Received: " + hexlify_packets(data))
if not self.control.ListenOnly:
continuation = lambda request: self._execute(request, addr)
self.framer.processIncomingPacket(data, continuation)
def resetFrame(self):
"""
Reset the entire message frame.
This allows us to skip over errors that may be in the stream.
It is hard to know if we are simply out of sync or if there is
an error in the stream as we have no way to check the start or
end of the message (python just doesn't have the resolution to
check for millisecond delays).
"""
_logger.debug("Resetting frame - Current Frame in "
"buffer - {}".format(hexlify_packets(self._buffer)))
self._buffer = b''
self._header = {}
def getFrame(self):
"""
Get the next frame from the buffer
:returns: The frame data or ''
"""
start = self._hsize
end = self._header['len'] - 2
buffer = self._buffer[start:end]
if end > 0:
_logger.debug("Getting Frame - {}".format(hexlify_packets(buffer)))
return buffer
return b''
def dataReceived(self, data):
""" Callback when we receive any data
:param data: The data sent by the client
"""
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Data Received: ' + hexlify_packets(data))
if not self.factory.control.ListenOnly:
units = self.factory.store.slaves()
single = self.factory.store.single
self.framer.processIncomingPacket(data, self._execute,
single=single,
unit=units)
def dataReceived(self, data):
""" Callback when we receive any data
:param data: The data sent by the client
"""
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Data Received: ' + hexlify_packets(data))
if not self.factory.control.ListenOnly:
units = self.factory.store.slaves()
single = self.factory.store.single
self.framer.processIncomingPacket(data, self._execute,
single=single,
unit=units)
def resetFrame(self):
"""
Reset the entire message frame.
This allows us to skip over errors that may be in the stream.
It is hard to know if we are simply out of sync or if there is
an error in the stream as we have no way to check the start or
end of the message (python just doesn't have the resolution to
check for millisecond delays).
"""
_logger.debug("Resetting frame - Current Frame in "
"buffer - {}".format(hexlify_packets(self._buffer)))
self._buffer = b''
self._header = {}
def getFrame(self):
"""
Get the next frame from the buffer
:returns: The frame data or ''
"""
start = self._hsize
end = self._header['len'] - 2
buffer = self._buffer[start:end]
if end > 0:
_logger.debug("Getting Frame - {}".format(hexlify_packets(buffer)))
return buffer
return b''
def callback(*args):
LOGGER.debug("in callback - {}".format(request.transaction_id))
while True:
waiting = self.stream.connection.in_waiting
if waiting:
data = self.stream.connection.read(waiting)
LOGGER.debug("recv: " + hexlify_packets(data))
unit = self.framer.decode_data(data).get("uid", 0)
self.framer.processIncomingPacket(
data,
self._handle_response,
unit,
tid=request.transaction_id)
break
def on_receive(self, *args):
"""
On data recieve call back
:param args: data received
:return:
"""
data = args[0] if len(args) > 0 else None
if not data:
return
LOGGER.debug("recv: " + hexlify_packets(data))
unit = self.framer.decode_data(data).get("unit", 0)
self.framer.processIncomingPacket(data,
self._handle_response,
unit=unit)
def dataReceived(self, data):
""" Callback when we receive any data
:param data: The data sent by the client
"""
log.event('Modbus, IPv4Address[{}]: Data Received (Raw): '.format(
self.transport.getPeer().host) + str(data))
log.event('Modbus, IPv4Address[{}]: Data Received (Hex): '.format(
self.transport.getPeer().host) + hexlify_packets(data))
if not self.factory.control.ListenOnly:
units = self.factory.store.slaves()
single = self.factory.store.single
self.framer.processIncomingPacket(data,
self._execute,
single=single,
unit=units)
def _execute(self, request):
# Build Framer Packet
request.transaction_id = self.transaction.getNextTID()
packet = self.framer.buildPacket(message=request)
logger.debug("send: " + hexlify_packets(packet))
# Send packet through QUIC
self.send(packet)
# Get response
waiter = self.client._loop.create_future()
self.transaction.addTransaction(waiter, request.transaction_id)
self._ack_waiter = waiter
self.client.transmit()
return waiter
def processIncomingPacket(self, data, callback, unit, **kwargs):
"""
The new packet processing pattern
This takes in a new request packet, adds it to the current
packet stream, and performs framing on it. That is, checks
for complete messages, and once found, will process all that
exist. This handles the case when we read N + 1 or 1 / N
messages at a time instead of 1.
The processed and decoded messages are pushed to the callback
function to process and send.
:param data: The new packet data
:param callback: The function to send results to
:param unit: Process if unit id matches, ignore otherwise (could be a
list of unit ids (server) or single unit id(client/server)
:param single: True or False (If True, ignore unit address validation)
"""
if not isinstance(unit, (list, tuple)):
unit = [unit]
single = kwargs.get("single", False)
_logger.debug("Processing: " + hexlify_packets(data))
self.addToFrame(data)
while True:
if self.isFrameReady():
if self.checkFrame():
if self._validate_unit_id(unit, single):
self._process(callback)
else:
_logger.debug("Not a valid unit id - {}, "
"ignoring!!".format(self._header['uid']))
self.resetFrame()
else:
_logger.debug("Frame check failed, ignoring!!")
self.resetFrame()
else:
if len(self._buffer):
# Possible error ???
if self._header['len'] < 2:
self._process(callback, error=True)
break
def processIncomingPacket(self, data, callback, unit, **kwargs):
"""
The new packet processing pattern
This takes in a new request packet, adds it to the current
packet stream, and performs framing on it. That is, checks
for complete messages, and once found, will process all that
exist. This handles the case when we read N + 1 or 1 // N
messages at a time instead of 1.
The processed and decoded messages are pushed to the callback
function to process and send.
:param data: The new packet data
:param callback: The function to send results to
:param unit: Process if unit id matches, ignore otherwise (could be a \
list of unit ids (server) or single unit id(client/server)
:param single: True or False (If True, ignore unit address validation)
:return:
"""
if not isinstance(unit, (list, tuple)):
unit = [unit]
single = kwargs.get("single", False)
_logger.debug("Processing: " + hexlify_packets(data))
self.addToFrame(data)
while True:
if self.isFrameReady():
if self.checkFrame():
if self._validate_unit_id(unit, single):
self._process(callback)
else:
_logger.debug("Not a valid unit id - {}, "
"ignoring!!".format(self._header['uid']))
self.resetFrame()
else:
_logger.debug("Frame check failed, ignoring!!")
self.resetFrame()
else:
if len(self._buffer):
# Possible error ???
if self._header['len'] < 2:
self._process(callback, error=True)
break
def testBaseModbusClient(self):
''' Test the base class for all the clients '''
client = BaseModbusClient(None)
client.transaction = None
self.assertRaises(NotImplementedException, lambda: client.connect())
self.assertRaises(NotImplementedException, lambda: client.send(None))
self.assertRaises(NotImplementedException, lambda: client.recv(None))
self.assertRaises(NotImplementedException, lambda: client.__enter__())
self.assertRaises(NotImplementedException, lambda: client.execute())
self.assertRaises(NotImplementedException,
lambda: client.is_socket_open())
self.assertEqual("Null Transport", str(client))
client.close()
client.__exit__(0, 0, 0)
# Test information methods
client.last_frame_end = 2
client.silent_interval = 2
self.assertEqual(4, client.idle_time())
client.last_frame_end = None
self.assertEqual(0, client.idle_time())
# Test debug/trace/_dump methods
self.assertEqual(False, client.debug_enabled())
writable = StringIO()
client.trace(writable)
client._dump(b'\x00\x01\x02', None)
self.assertEqual(hexlify_packets(b'\x00\x01\x02'), writable.getvalue())
# a successful execute
client.connect = lambda: True
client.transaction = Mock(**{'execute.return_value': True})
self.assertEqual(client, client.__enter__())
self.assertTrue(client.execute())
# a unsuccessful connect
client.connect = lambda: False
self.assertRaises(ConnectionException, lambda: client.__enter__())
self.assertRaises(ConnectionException, lambda: client.execute())
def _on_timeout():
LOGGER.warning("timeout")
_clear_timer()
if self.stream:
self.io_loop.remove_handler(self.stream.fileno())
self.framer.resetFrame()
transaction = self.transaction.getTransaction(request.transaction_id)
if self.state != ModbusTransactionState.IDLE:
self.state = ModbusTransactionState.IDLE
if self.stream:
try:
waiting = self.stream.connection.in_waiting
if waiting:
result = self.stream.connection.read(waiting)
LOGGER.info(
"Cleanup recv buffer after timeout: " + hexlify_packets(result))
except OSError as ex:
self.close()
if transaction:
transaction.set_exception(ModbusIOException(ex))
return
if transaction:
transaction.set_exception(TimeOutException())
def _on_receive(fd, events):
"""
New data in serial buffer to read or serial port closed
"""
if events & IOLoop.ERROR:
_on_fd_error(fd)
return
try:
waiting = self.stream.connection.in_waiting
if waiting:
data = self.stream.connection.read(waiting)
LOGGER.debug("recv: " + hexlify_packets(data))
self.last_frame_end = round(time.time(), 6)
except OSError as ex:
_on_fd_error(fd, ex)
return
self.framer.addToFrame(data)
# check if we have regular frame or modbus exception
fcode = self.framer.decode_data(self.framer.getRawFrame()).get(
"fcode", 0)
if fcode and (
(fcode > 0x80 and len(self.framer.getRawFrame())
== exception_response_length) or
(len(self.framer.getRawFrame()) == expected_response_length)):
_clear_timer()
self.io_loop.remove_handler(fd)
self.state = ModbusTransactionState.IDLE
self.framer.processIncomingPacket(
b'', # already sent via addToFrame()
self._handle_response,
0, # don't care when `single=True`
single=True,
tid=request.transaction_id)
def dataReceived(self, data):
logger.debug("recv: " + hexlify_packets(data))
unit = self.framer.decode_data(data=data).get("unit", 0)
self.framer.processIncomingPacket(data,
self._handleResponse,
unit=unit)
def execute(self, request):
""" Starts the producer to send the next request to
consumer.write(Frame(request))
"""
with self._transaction_lock:
try:
_logger.debug("Current transaction state - {}".format(
ModbusTransactionState.to_string(self.client.state))
)
retries = self.retries
request.transaction_id = self.getNextTID()
_logger.debug("Running transaction "
"{}".format(request.transaction_id))
_buffer = hexlify_packets(self.client.framer._buffer)
if _buffer:
_logger.debug("Clearing current Frame "
": - {}".format(_buffer))
self.client.framer.resetFrame()
broadcast = (self.client.broadcast_enable
and request.unit_id == 0)
if broadcast:
self._transact(request, None, broadcast=True)
response = b'Broadcast write sent - no response expected'
else:
expected_response_length = None
if not isinstance(self.client.framer, ModbusSocketFramer):
if hasattr(request, "get_response_pdu_size"):
response_pdu_size = request.get_response_pdu_size()
if isinstance(self.client.framer, ModbusAsciiFramer):
response_pdu_size = response_pdu_size * 2
if response_pdu_size:
expected_response_length = self._calculate_response_length(response_pdu_size)
if request.unit_id in self._no_response_devices:
full = True
else:
full = False
c_str = str(self.client)
if "modbusudpclient" in c_str.lower().strip():
full = True
if not expected_response_length:
expected_response_length = Defaults.ReadSize
response, last_exception = self._transact(
request,
expected_response_length,
full=full,
broadcast=broadcast
)
if not response and (
request.unit_id not in self._no_response_devices):
self._no_response_devices.append(request.unit_id)
elif request.unit_id in self._no_response_devices and response:
self._no_response_devices.remove(request.unit_id)
if not response and self.retry_on_empty and retries:
while retries > 0:
if hasattr(self.client, "state"):
_logger.debug("RESETTING Transaction state to "
"'IDLE' for retry")
self.client.state = ModbusTransactionState.IDLE
_logger.debug("Retry on empty - {}".format(retries))
response, last_exception = self._transact(
request,
expected_response_length
)
if not response:
retries -= 1
continue
# Remove entry
self._no_response_devices.remove(request.unit_id)
break
addTransaction = partial(self.addTransaction,
tid=request.transaction_id)
self.client.framer.processIncomingPacket(response,
addTransaction,
request.unit_id)
response = self.getTransaction(request.transaction_id)
if not response:
if len(self.transactions):
response = self.getTransaction(tid=0)
else:
last_exception = last_exception or (
"No Response received from the remote unit"
"/Unable to decode response")
response = ModbusIOException(last_exception,
request.function_code)
if hasattr(self.client, "state"):
_logger.debug("Changing transaction state from "
"'PROCESSING REPLY' to "
"'TRANSACTION_COMPLETE'")
self.client.state = (
ModbusTransactionState.TRANSACTION_COMPLETE)
return response
except ModbusIOException as ex:
# Handle decode errors in processIncomingPacket method
_logger.exception(ex)
self.client.state = ModbusTransactionState.TRANSACTION_COMPLETE
return ex
async def handle(self):
"""Asyncio coroutine which represents a single conversation between
the modbus slave and master
Once the client connection is established, the data chunks will be
fed to this coroutine via the asyncio.Queue object which is fed by
the ModbusBaseRequestHandler class's callback Future.
This callback future gets data from either asyncio.DatagramProtocol.datagram_received
or from asyncio.BaseProtocol.data_received.
This function will execute without blocking in the while-loop and
yield to the asyncio event loop when the frame is exhausted.
As a result, multiple clients can be interleaved without any
interference between them.
For ModbusConnectedRequestHandler, each connection will be given an
instance of the handle() coroutine and this instance will be put in the
active_connections dict. Calling server_close will individually cancel
each running handle() task.
For ModbusDisconnectedRequestHandler, a single handle() coroutine will
be started and maintained. Calling server_close will cancel that task.
"""
reset_frame = False
while self.running:
try:
units = self.server.context.slaves()
data = await self._recv_(
) # this is an asyncio.Queue await, it will never fail
if isinstance(data, tuple):
data, *addr = data # addr is populated when talking over UDP
else:
addr = (None, ) # empty tuple
if not isinstance(units, (list, tuple)):
units = [units]
# if broadcast is enabled make sure to
# process requests to address 0
if self.server.broadcast_enable: # pragma: no cover
if 0 not in units:
units.append(0)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
single = self.server.context.single
self.framer.processIncomingPacket(
data=data,
callback=lambda x: self.execute(x, *addr),
unit=units,
single=single)
except asyncio.CancelledError:
# catch and ignore cancelation errors
if isinstance(self, ModbusConnectedRequestHandler):
_logger.debug(
"Handler for stream [%s:%s] has been canceled" %
self.client_address)
else:
_logger.debug(
"Handler for UDP socket [%s] has been canceled" %
self.protocol._sock.getsockname()[1])
except Exception as e:
# force TCP socket termination as processIncomingPacket should handle applicaiton layer errors
# for UDP sockets, simply reset the frame
if isinstance(self, ModbusConnectedRequestHandler):
_logger.info(
"Unknown exception '%s' on stream [%s:%s] forcing disconnect"
% (e, *self.client_address))
self.transport.close()
else:
_logger.error("Unknown error occurred %s" % e)
reset_frame = True # graceful recovery
finally:
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def execute(self, request=None):
"""
Executes a transaction
:param request: Request to be written on to the bus
:return:
"""
request.transaction_id = self.transaction.getNextTID()
def _clear_timer():
LOGGER.debug("_clear_timer()")
if self.timeout_handle:
self.io_loop.remove_timeout(self.timeout_handle)
self.timeout_handle = None
def _on_timeout():
LOGGER.warning("timeout")
_clear_timer()
if self.stream:
self.io_loop.remove_handler(self.stream.fileno())
self.framer.resetFrame()
transaction = self.transaction.getTransaction(request.transaction_id)
if self.state != ModbusTransactionState.IDLE:
self.state = ModbusTransactionState.IDLE
if self.stream:
try:
waiting = self.stream.connection.in_waiting
if waiting:
result = self.stream.connection.read(waiting)
LOGGER.info(
"Cleanup recv buffer after timeout: " + hexlify_packets(result))
except OSError as ex:
self.close()
if transaction:
transaction.set_exception(ModbusIOException(ex))
return
if transaction:
transaction.set_exception(TimeOutException())
def _on_write_done(*args):
LOGGER.debug("frame sent, waiting for a reply")
self.last_frame_end = round(time.time(), 6)
self.state = ModbusTransactionState.WAITING_FOR_REPLY
self.io_loop.add_handler(self.stream.fileno(), _on_receive, IOLoop.READ)
def _on_receive(fd, events):
LOGGER.debug("_on_receive: %s, %s", fd, events)
try:
waiting = self.stream.connection.in_waiting
if waiting:
LOGGER.debug("waiting = %d", waiting)
data = self.stream.connection.read(waiting)
LOGGER.debug(
"recv: " + hexlify_packets(data))
except OSError as ex:
_clear_timer()
self.close()
self.transaction.getTransaction(request.transaction_id).set_exception(ModbusIOException(ex))
return
self.framer.addToFrame(data)
# check if we have regular frame or modbus exception
fcode = self.framer.decode_data(self.framer.getRawFrame()).get("fcode", 0)
if fcode and (
(fcode > 0x80 and len(self.framer.getRawFrame()) == exception_response_length)
or
(len(self.framer.getRawFrame()) == expected_response_length)
):
_clear_timer()
self.io_loop.remove_handler(fd)
self.state = ModbusTransactionState.IDLE
self.framer.processIncomingPacket(
b'', # already sent via addToFrame()
self._handle_response,
0, # don't care for `single=True`
single=True,
tid=request.transaction_id
)
LOGGER.debug("set timeout for %f sec", self.timeout)
self.timeout_handle = self.io_loop.add_timeout(time.time() + self.timeout, _on_timeout)
response_pdu_size = request.get_response_pdu_size()
expected_response_length = self.transaction._calculate_response_length(response_pdu_size)
LOGGER.debug("expected_response_length = %d", expected_response_length)
exception_response_length = self.transaction._calculate_exception_length() # TODO: this does not change
packet = self.framer.buildPacket(request)
LOGGER.debug("send: " + hexlify_packets(packet))
self.state = ModbusTransactionState.SENDING
f = self._build_response(request.transaction_id)
self._sendPacket(packet, callback=_on_write_done)
return f
