From 0de88ff0fb69b49d10624d94b0893a11ffad7e3f Mon Sep 17 00:00:00 2001
From: Philippe Gauthier <philippe.gauthier@deuxpi.ca>
Date: Thu, 29 Mar 2012 17:34:08 -0400
Subject: [PATCH] Fix binary framer and add start and end tokens

Fixes a TypeError occuring while escaping token bytes in the message and
adds the start and end tokens to the packet.
---
 pymodbus/transaction.py  | 3 ++-
 test/test_transaction.py | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/pymodbus/transaction.py b/pymodbus/transaction.py
index 4118ba826..9bfc4d779 100644
--- a/pymodbus/transaction.py
+++ b/pymodbus/transaction.py
@@ -742,6 +742,7 @@ def buildPacket(self, message):
             message.unit_id,
             message.function_code) + data
         packet += struct.pack(">H", computeCRC(packet))
+        packet = '%s%s%s' % (self.__start, packet, self.__end)
         return packet
 
     def _preflight(self, data):
@@ -755,7 +756,7 @@ def _preflight(self, data):
         '''
         def _filter(a):
             if a in ['}', '{']: return a * 2
-            else: return a, data
+            else: return a
         return ''.join(map(_filter, data))
 
 #---------------------------------------------------------------------------#
diff --git a/test/test_transaction.py b/test/test_transaction.py
index a0ac8c7ad..2df2736f6 100644
--- a/test/test_transaction.py
+++ b/test/test_transaction.py
@@ -340,7 +340,7 @@ def testBinaryFramerPacket(self):
         message = ModbusRequest()
         message.unit_id        = 0xff
         message.function_code  = 0x01
-        expected = '\xff\x01\x81\x80'
+        expected = '\x7b\xff\x01\x81\x80\x7d'
         actual = self._binary.buildPacket(message)
         self.assertEqual(expected, actual)
         ModbusRequest.encode = old_encode