Index: dialin/hd/air_trap.py
===================================================================
diff -u -rc8ab70ecfe3130fa98bc1626d905f323d7f4c7f3 -r924c42da99eaad59a4565fbd5dfedfa68f5dfe25
--- dialin/hd/air_trap.py	(.../air_trap.py)	(revision c8ab70ecfe3130fa98bc1626d905f323d7f4c7f3)
+++ dialin/hd/air_trap.py	(.../air_trap.py)	(revision 924c42da99eaad59a4565fbd5dfedfa68f5dfe25)
@@ -16,6 +16,7 @@
 import struct
 from ..utils.conversions import integer_to_bytearray, float_to_bytearray
 from .constants import RESET,NO_RESET
+from ..common.msg_defs import MsgIds
 from ..protocols.CAN import (DenaliMessage,
                              DenaliChannels)
 from ..utils.base import _AbstractSubSystem, _publish
@@ -54,7 +55,7 @@
 
         if self.can_interface is not None:
             channel_id = DenaliChannels.hd_sync_broadcast_ch_id
-            msg_id = self.MSG_ID_HD_AIR_TRAP_DATA
+            msg_id = MsgIds.MSG_ID_HD_AIR_TRAP_DATA
             self.can_interface.register_receiving_publication_function(channel_id, msg_id,
                                                                        self._handler_air_trap_sync)
 
@@ -126,7 +127,7 @@
         payload = rst + det + idx
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_hd_ch_id,
-                                              message_id=self.MSG_ID_DG_AIR_TRAP_LEVEL_SENSOR_OVERRIDE,
+                                              message_id=MsgIds.MSG_ID_DG_AIR_TRAP_LEVEL_SENSOR_OVERRIDE,
                                               payload=payload)
 
         self.logger.debug("override air trap level sensor detection value for sensor " + str(sensor))
@@ -159,7 +160,7 @@
         payload = rst + mis
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_hd_ch_id,
-                                              message_id=self.MSG_ID_DG_AIR_TRAP_DATA_BROADCAST_INTERVAL_OVERRIDE,
+                                              message_id=MsgIds.MSG_ID_DG_AIR_TRAP_DATA_BROADCAST_INTERVAL_OVERRIDE,
                                               payload=payload)
 
         self.logger.debug("override HD air trap data broadcast interval")
Index: dialin/hd/hemodialysis_device.py
===================================================================
diff -u -rc7effef22561b1c003184091240009e379835f74 -r924c42da99eaad59a4565fbd5dfedfa68f5dfe25
--- dialin/hd/hemodialysis_device.py	(.../hemodialysis_device.py)	(revision c7effef22561b1c003184091240009e379835f74)
+++ dialin/hd/hemodialysis_device.py	(.../hemodialysis_device.py)	(revision 924c42da99eaad59a4565fbd5dfedfa68f5dfe25)
@@ -32,6 +32,7 @@
 from ..utils.conversions import integer_to_bytearray
 from ..utils.base import _AbstractSubSystem, _publish, _LogManager
 from .constants import NO_RESET
+from ..common.msg_defs import MsgIds
 
 
 class HD(_AbstractSubSystem):
@@ -40,13 +41,6 @@
     the HD firmware.
     """
 
-    # HD message IDs
-    MSG_ID_HD_OPERATION_MODE_BROADCAST = 0x0025
-    MSG_ID_POWEROFF_NOTIFY = 0x0020
-    MSG_ID_LOGIN_TO_HD = 0x8000
-    MSG_ID_HD_SAFETY_SHUTDOWN_OVERRIDE = 0x8026
-    MSG_ID_HD_SOFTWARE_RESET_REQUEST = 0x8034
-
     # broadcast message field positions
     START_POS_HD_OP_MODE = DenaliMessage.PAYLOAD_START_INDEX
     END_POS_HD_OP_MODE = START_POS_HD_OP_MODE + 4
@@ -95,7 +89,7 @@
         # register handler for HD operation mode broadcast messages
         if self.can_interface is not None:
             channel_id = DenaliChannels.hd_sync_broadcast_ch_id
-            msg_id = self.MSG_ID_HD_OPERATION_MODE_BROADCAST
+            msg_id = MsgIds.MSG_ID_HD_OP_MODE
             self.can_interface.register_receiving_publication_function(channel_id, msg_id,
                                                                        self._handler_hd_op_mode_sync)
 
@@ -151,7 +145,7 @@
         """
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_hd_ch_id,
-                                              message_id=self.MSG_ID_LOGIN_TO_HD,
+                                              message_id=MsgIds.MSG_ID_TESTER_LOGIN_REQUEST,
                                               payload=list(map(int, map(ord, self.HD_LOGIN_PASSWORD))))
 
         self.logger.debug("Logging in...")
@@ -192,7 +186,7 @@
         payload = rst + saf
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_hd_ch_id,
-                                              message_id=self.MSG_ID_HD_SAFETY_SHUTDOWN_OVERRIDE,
+                                              message_id=MsgIds.MSG_ID_HD_SAFETY_SHUTDOWN_OVERRIDE,
                                               payload=payload)
 
         self.logger.debug("overriding HD safety shutdown")
@@ -223,7 +217,7 @@
         """
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_hd_ch_id,
-                                              message_id=self.MSG_ID_HD_SOFTWARE_RESET_REQUEST)
+                                              message_id=MsgIds.MSG_ID_HD_SOFTWARE_RESET_REQUEST)
 
         self.logger.debug("requesting HD software reset")