Index: leahi_dialin/protocols/CAN.py
===================================================================
diff -u -r779949e7648b7957c57ad970c4056e91abc0819d -r6d104d3185ac3ed7c18c97ecdc13fd59bf53a8d1
--- leahi_dialin/protocols/CAN.py	(.../CAN.py)	(revision 779949e7648b7957c57ad970c4056e91abc0819d)
+++ leahi_dialin/protocols/CAN.py	(.../CAN.py)	(revision 6d104d3185ac3ed7c18c97ecdc13fd59bf53a8d1)
@@ -24,16 +24,13 @@
 from can.interfaces import socketcan
 import math
 from time import sleep
-from datetime import datetime
 import sys
 from logging import Logger
 import struct
-from .. import common
-from ..common import MsgIds, msg_defs
+from ..common import MsgIds, MSG_HEADER_SIZE, ACK_NOT_REQUIRED
 from ..utils import SingletonMeta, IntervalTimer
 from concurrent.futures import ThreadPoolExecutor
 
-import os
 
 class DenaliMessage:
     BYTE_ORDER = 'little'
@@ -42,7 +39,7 @@
     MSG_SEQ_INDEX = 1
     MSG_ID_INDEX = 3
     PAYLOAD_LENGTH_INDEX = 5
-    PAYLOAD_START_INDEX = 6
+    PAYLOAD_START_INDEX = MSG_HEADER_SIZE
     PAYLOAD_LENGTH_FIRST_PACKET = 1
     HEADER_LENGTH = 6
     PACKET_LENGTH = 8
@@ -107,7 +104,7 @@
 
                 seq = cls._seq_num
 
-                if message_id not in common.msg_defs.ACK_NOT_REQUIRED:
+                if message_id not in ACK_NOT_REQUIRED:
                     seq *= -1
 
             message_seq_in_bytes = seq.to_bytes(2, byteorder=DenaliMessage.BYTE_ORDER, signed=True)
@@ -297,7 +294,7 @@
 
         message = DenaliMessage.build_message(
             channel_id=channel_id_tx,
-            message_id=common.msg_defs.MsgIds.MSG_ID_ACK_MESSAGE_THAT_REQUIRES_ACK.value,
+            message_id=MsgIds.MSG_ID_ACK_MESSAGE_THAT_REQUIRES_ACK.value,
             payload=payload,
             seq=-seq)