Index: leahi_dialin/common/msg_defs.py
===================================================================
diff -u -r41de945f9c773e54e965e80d9e46def828beb732 -r6d104d3185ac3ed7c18c97ecdc13fd59bf53a8d1
--- leahi_dialin/common/msg_defs.py	(.../msg_defs.py)	(revision 41de945f9c773e54e965e80d9e46def828beb732)
+++ leahi_dialin/common/msg_defs.py	(.../msg_defs.py)	(revision 6d104d3185ac3ed7c18c97ecdc13fd59bf53a8d1)
@@ -14,10 +14,10 @@
 #
 ############################################################################
 from enum import unique
-from ..utils.base import DialinEnum
+from ..utils.enums import DialinEnum
 from .msg_ids import MsgIds
 
-
+MSG_HEADER_SIZE = 6         # Hardcoded for now to avoid cyclic import issue. See protocols.CAN.DenaliMessage class
 ACK_NOT_REQUIRED = [
 
 ]
@@ -75,9 +75,10 @@
     REQUEST_REJECT_REASON_TREATMENT_CANNOT_BE_RESUMED = 47
 RequestRejectReasons._str_list = {}
 
+
 class MsgFieldPositions:
     # Generic response msg field byte positions (where 32-bit data fields are used)
-    START_POS_FIELD_1 = 6  # Hardcoded for now to avoid cyclic import issue. See protocols.CAN.DenaliMessage class
+    START_POS_FIELD_1 = MSG_HEADER_SIZE         # Hardcoded for now to avoid cyclic import issue. See protocols.CAN.DenaliMessage class
     END_POS_FIELD_1 = START_POS_FIELD_1 + 4
     START_POS_FIELD_2 = END_POS_FIELD_1
     END_POS_FIELD_2 = START_POS_FIELD_2 + 4
@@ -139,7 +140,7 @@
 
 class MsgFieldPositionsFWVersions:
     # UI version message field positions
-    START_POS_MAJOR = 6 # Hardcoded for now to avoid cyclic import issue. See protocols.CAN.DenaliMessage class
+    START_POS_MAJOR = MSG_HEADER_SIZE       # Hardcoded for now to avoid cyclic import issue. See protocols.CAN.DenaliMessage class
     END_POS_MAJOR = START_POS_MAJOR + 1
     START_POS_MINOR = END_POS_MAJOR
     END_POS_MINOR = START_POS_MINOR + 1