Index: TD_HDF/loader.py
===================================================================
diff -u -r31a04301e0719002e80528c8d1e08aa452925f78 -rfc43fc2ed484aec6f49ef1c7f67a71c4d0d5d0d3
--- TD_HDF/loader.py	(.../loader.py)	(revision 31a04301e0719002e80528c8d1e08aa452925f78)
+++ TD_HDF/loader.py	(.../loader.py)	(revision fc43fc2ed484aec6f49ef1c7f67a71c4d0d5d0d3)
@@ -14,7 +14,8 @@
 from engine.dynamicloader   import DynamicLoader
 
 # plugin specific
-from leahi_dialin.common.msg_defs import MsgIds, MsgFieldPositions
+from leahi_dialin.common.msg_ids    import MsgIds
+from leahi_dialin.common.constants  import MSG_HEADER_SIZE
 from leahi_dialin.protocols       import CAN
 from leahi_dialin.utils           import conversions
 
@@ -207,7 +208,7 @@
         @return: None
         """
         message = message['message']
-        index = MsgFieldPositions.START_POS_FIELD_1
+        index = MSG_HEADER_SIZE
         value,index = conversions.bytearray_to_integer(message, index)
         cmdString = self.hdfState[value] if value >= 0 and value < len(self.hdfState) else "<unknown>"
         self.lbHDFState.setText(f"{cmdString} ({value})")
@@ -220,7 +221,7 @@
         @return: None
         """
         message = message['message']
-        index = MsgFieldPositions.START_POS_FIELD_1
+        index = MSG_HEADER_SIZE
         value,index = conversions.bytearray_to_integer(message, index)
         cmdString = self.autoSubState[value] if value >= 0 and value < len(self.autoSubState) else "<unknown>"
         self.lbAutoSub.setText(f"{cmdString} ({value})")
@@ -233,7 +234,7 @@
         @return: None
         """
         message = message['message']
-        index = MsgFieldPositions.START_POS_FIELD_1
+        index = MSG_HEADER_SIZE
         txMode,index    = conversions.bytearray_to_integer  (message, index)
         vol,index       = conversions.bytearray_to_float    (message, index)
         self.lbtxMode           .setText(f"{txMode}")