Fix #387 Transactions failing on 2.2.0rc2.

Author: dhoomakethu

CHANGELOG.rst

@@ -18,6 +18,7 @@ from pymodbus.client.asynchronous import ModbusTcpClient
 * Support broadcasting in Modbus Client and Servers (sync).
 * Fix asyncio examples.
 * Improved logging in Modbus Server .
+* Fix regression introduced in 2.2.0rc2 (Modbus sync client transaction failing)
 * Minor update in factory.py, now server logs prints received request instead of only function code
 
 ```

pymodbus/server/sync.py

@@ -181,14 +181,21 @@ def handle(self):
         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))
-                # 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)

pymodbus/transaction.py

@@ -112,14 +112,17 @@ def execute(self, request):
                 )
                 retries = self.retries
                 request.transaction_id = self.getNextTID()
-                _logger.debug("Running transaction %d" % request.transaction_id)
+                _logger.debug("Running transaction "
+                              "{}".format(request.transaction_id))
                 _buffer = hexlify_packets(self.client.framer._buffer)
                 if _buffer:
-                    _logger.debug("Clearing current Frame : - {}".format(_buffer))
+                    _logger.debug("Clearing current Frame "
+                                  ": - {}".format(_buffer))
                     self.client.framer.resetFrame()
-
-                if request.unit_id == 0 and self.client.broadcast_enable:
-                    response, last_exception = self._transact(request, None)
+                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
@@ -139,10 +142,12 @@ def execute(self, request):
                         full = True
                         if not expected_response_length:
                             expected_response_length = Defaults.ReadSize
-                    response, last_exception = self._transact(request,
-                                                              expected_response_length,
-                                                              full=full
-                                                              )
+                    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)
@@ -193,7 +198,7 @@ def execute(self, request):
                 self.client.state = ModbusTransactionState.TRANSACTION_COMPLETE
                 return ex
 
-    def _transact(self, packet, response_length, full=False):
+    def _transact(self, packet, response_length, full=False, broadcast=False):
         """
         Does a Write and Read transaction
         :param packet: packet to be sent
@@ -209,20 +214,20 @@ def _transact(self, packet, response_length, full=False):
             if _logger.isEnabledFor(logging.DEBUG):
                 _logger.debug("SEND: " + hexlify_packets(packet))
             size = self._send(packet)
-            if response_length is not None:
-                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))
-            else:
+            if broadcast:
                 if size:
                     _logger.debug("Changing transaction state from 'SENDING' "
                                   "to 'TRANSACTION_COMPLETE'")
                     self.client.state = ModbusTransactionState.TRANSACTION_COMPLETE
-                result = b''
+                return b'', None
+            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()

pymodbus/version.py

@@ -41,7 +41,7 @@ def __str__(self):
         return '[%s, version %s]' % (self.package, self.short())
 
 
-version = Version('pymodbus', 2, 2, 0, "rc2")
+version = Version('pymodbus', 2, 2, 0, "rc3")
 
 
 version.__name__ = 'pymodbus'  # fix epydoc error