/
client.py
executable file
·255 lines (238 loc) · 10.7 KB
/
client.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
"""
Implementation of a Modbus Client Using Tornado
-----------------------------------------------
Example run:
from pymodbus_async.client import AsyncModbusSerialClient
from pymodbus.exceptions import ConnectionException, ModbusIOException
from pymodbus.register_read_message import ReadHoldingRegistersResponse
import tornado.ioloop
import sys
def read_async():
client = AsyncModbusSerialClient(method='rtu', stopbits=1, bytesize=8, parity='E', baudrate=19200, timeout=1, port='/dev/ttyUSB0')
try:
res = client.read_holding_registers(address=0, count=1, unit=1)
except ConnectionException as ex:
print("ConnectionException: %s" % str(ex))
sys.exit()
except ModbusIOException as ex:
print("ModbusIOException: %s" % str(ex))
sys.exit()
res.addCallback(async_reply)
def async_reply(result):
if isinstance(result, ReadHoldingRegistersResponse):
print("registers: %s" % str(result.registers))
else:
print("ERROR: %s" % str(result))
tornado.ioloop.IOLoop.instance().stop()
read_async()
tornado.ioloop.IOLoop.instance().start()
"""
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
from pymodbus.transaction import ModbusRtuFramer
from pymodbus.register_read_message import ReadHoldingRegistersRequest
from pymodbus.transaction import FifoTransactionManager
from pymodbus.client.sync import BaseModbusClient
from pymodbus.exceptions import ModbusIOException, NotImplementedException
from pymodbus.client.sync import ModbusSerialClient
from pymodbus.constants import Defaults
from pymodbus.factory import ClientDecoder
from pymodbus.pdu import ModbusResponse
from pymodbus.compat import byte2int
import socket
import tornado.ioloop
from functools import partial
import serial
import time
import datetime
import logging
_logger = logging.getLogger(__name__)
class AsyncErrorResponse(ModbusResponse):
SerialConnectionError = 1
SerialWriteError = 2
SerialReadError = 3
SerialReadTimeout = 4
def __init__(self, error_code, **kwargs):
_logger.info("AsyncErrorResponse.__init__()")
super(AsyncErrorResponse, self).__init__(**kwargs)
self.error_code = error_code
class AsyncModbusRtuFramer(ModbusRtuFramer):
def __init__(self, decoder):
_logger.info("AsyncModbusRtuFramer.__init__()")
super(AsyncModbusRtuFramer, self).__init__(decoder)
self.__buffer = b'' # we can't access ModbusRtuFramer.__buffer
self.__buflen = 0
def addToFrame(self, message):
ModbusRtuFramer.addToFrame(self, message)
self.__buffer += message
self.__buflen = self.__buflen + len(message)
def resetFrame(self):
ModbusRtuFramer.resetFrame(self)
self.__buffer = b''
self.__buflen = 0
def isFrameReady(self):
_logger.info("AsyncModbusRtuFramer.isFrameReady()")
if self.decoder:
_logger.info("self.decoder: %s", str(self.decoder))
return ModbusRtuFramer.isFrameReady(self)
def getFrameLen(self):
return self.__buflen
def isExceptionFrame(self):
if self.__buflen == 5 and byte2int(self.__buffer[1]) > 0x80:
return True
return False
def processIncomingPacket(self, data, callback):
_logger.info("AsyncModbusRtuFramer.processIncomingPacket(%s)", str(data))
_logger.debug(" FRAME READY? " + str(self.isFrameReady()))
while self.isFrameReady():
_logger.debug(" FRAME CHECK? " + str(self.checkFrame()))
if self.checkFrame():
result = self.decoder.decode(self.getFrame())
if result is None:
raise ModbusIOException("Unable to decode response")
self.populateResult(result)
self.advanceFrame()
self.resetFrame()
callback(result) # defer or push to a thread?
return
else: self.resetFrame() # clear possible errors
def processError(self, error, callback):
_logger.info("AsyncModbusRtuFramer.processError(%s)", str(error))
self.resetFrame()
result = AsyncErrorResponse(error)
callback(result)
class AsyncFifoTransactionManager(FifoTransactionManager):
def execute(self, request):
_logger.info("AsyncFifoTransactionManager.execute(%s)", str(request))
self.request = request
self.request.transaction_id = self.getNextTID()
self.frame = self.client.framer.buildPacket(self.request)
try:
self.recvsize = self.client.framer.getResponseSize(self.request)
except NotImplementedException:
self.recvsize = 0;
time_since_last_read = time.time() - self.client._last_frame_end
_logger.info(" time_since_last_read: %f, _silent_interval: %f", time_since_last_read, self.client._silent_interval)
if time_since_last_read < self.client._silent_interval:
_logger.debug(" will delay to wait for 3.5 char")
self.client.ioloop.add_timeout(datetime.timedelta(seconds=(self.client._silent_interval - time_since_last_read)), partial(self._sendAsyncRequest, self.frame))
else:
try:
self._sendSyncRequest(self.frame)
except socket.error as ex:
self.delTransaction(self.request.transaction_id)
raise ModbusIOException(str(ex))
return self._buildResponse(self.request.transaction_id)
def _sendSyncRequest(self, data):
try:
self.client._send(self.frame)
except socket.error as ex:
self.client.close()
_logger.debug(" Transaction failed. (%s) " % ex)
raise ex
def _sendAsyncRequest(self, data):
try:
self.client._send(self.frame)
except socket.error as msg:
self.client.close()
_logger.debug(" Transaction failed. (%s) " % msg)
self.client.framer.processError(AsyncErrorResponse.SerialWriteError, self.client._handleResponse)
def _buildResponse(self, tid):
_logger.info("AsyncFifoTransactionManager._buildResponse(%s)", str(tid))
d = self
self.addTransaction(d, tid)
return d
def addCallback(self, cb):
_logger.info("AsyncFifoTransactionManager.addCallback(%s)", str(cb))
self.callback = cb
def executeCallback(self, reply):
_logger.info("AsyncFifoTransactionManager.executeCallback(%s)", str(reply))
if self.callback:
self.callback(reply)
class AsyncModbusClient(BaseModbusClient):
def __init__(self, framer):
_logger.info("AsyncModbusClient.__init__()")
self.framer = framer
self.transaction = AsyncFifoTransactionManager(self)
class AsyncModbusSerialClient(ModbusSerialClient):
def __init__(self, method='ascii', **kwargs):
_logger.info("AsyncModbusSerialClient.__init__()")
self.method = method
self.socket = None
AsyncModbusClient.__init__(self, self.__implementation(method))
self.port = kwargs.get('port', 0)
self.stopbits = kwargs.get('stopbits', Defaults.Stopbits)
self.bytesize = kwargs.get('bytesize', Defaults.Bytesize)
self.parity = kwargs.get('parity', Defaults.Parity)
self.baudrate = kwargs.get('baudrate', Defaults.Baudrate)
self.timeout = kwargs.get('timeout', Defaults.Timeout) or Defaults.Timeout
self._last_frame_end = 0.0
self._silent_interval = 3.5 * (1 + 8 + 2) / self.baudrate
self.ioloop = tornado.ioloop.IOLoop.instance()
self.timer = None
@staticmethod
def __implementation(method):
method = method.lower()
if method == 'rtu': return AsyncModbusRtuFramer(ClientDecoder())
raise ParameterException("Unsupported framer method requested")
def connect(self):
_logger.info("AsyncModbusSerialClient.connect()")
if self.socket: return True
timeout = self.timeout # remember timeout
self.timeout = 0 # use non-blocking serial
res = ModbusSerialClient.connect(self)
self.timeout = timeout
if self.socket:
self.ioloop.add_handler(self.socket.fileno(), partial(self.dataReceived, self.socket), self.ioloop.READ)
return res
def close(self):
if self.socket:
self.ioloop.remove_handler(self.socket.fileno())
return ModbusSerialClient.close(self)
def dataReceived(self, socket, fd, events):
_logger.info("AsyncModbusSerialClient.dataReceived(%s, %s, %s)", str(socket), str(fd), str(events))
if events & self.ioloop.ERROR:
_logger.critical("Serial ERROR")
self.framer.processError(AsyncErrorResponse.SerialConnectionError, self._handleResponse)
return
try:
data = socket.read(65535)
except serial.serialutil.SerialException as msg:
_logger.critical("SerialException: %s", str(msg))
self.framer.processError(AsyncErrorResponse.SerialReadError, self._handleResponse)
return
_logger.debug("DATA: %s", str(data))
self.framer.addToFrame(data)
if self.framer.isExceptionFrame():
self.framer.processIncomingPacket(data, self._handleResponse)
return
if self.transaction.recvsize:
if self.framer.getFrameLen() < self.transaction.recvsize:
_logger.debug(" not enough data yet")
return
self.framer.processIncomingPacket(data, self._handleResponse)
def _handleResponse(self, reply):
_logger.info("AsyncModbusSerialClient._handleResponse(%s)", str(reply))
if self.timer:
self.ioloop.remove_timeout(self.timer)
self.timer = None
self.framer.resetFrame()
if reply is not None:
tid = reply.transaction_id
handler = self.transaction.getTransaction(tid)
if handler:
handler.executeCallback(reply)
else: _logger.error(" Unrequested message: " + str(reply))
def _send(self, request):
_logger.info("AsyncModbusSerialClient._send(%s)", str(request))
super(AsyncModbusSerialClient, self)._send(request)
self._last_frame_end = time.time()
if self.timeout:
self.timer = self.ioloop.add_timeout(datetime.timedelta(seconds=self.timeout), self._timeout)
def _recv(self, size):
_logger.info("AsyncModbusSerialClient._recv((%d)", size)
result = self.socket.read(size)
self._last_frame_end = time.time()
return result
def _timeout(self):
_logger.info("AsyncModbusSerialClient._timeout()")
self.framer.processError(AsyncErrorResponse.SerialReadTimeout, self._handleResponse)