Index: firmware/App/Modes/OperationModes.c
===================================================================
diff -u -r8466e63f95f65a3ffb18c3af85ac99328e41167b -rc137d3c7cb17b0364d745e10ff6dbd1901eb1baa
--- firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision 8466e63f95f65a3ffb18c3af85ac99328e41167b)
+++ firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision c137d3c7cb17b0364d745e10ff6dbd1901eb1baa)
@@ -1,17 +1,17 @@
 /**************************************************************************
 *
-* Copyright (c) 2019-2020 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2019-2021 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
-* @file OperationModes.c
+* @file    OperationModes.c
 *
-* @author (last) Sean Nash
-* @date (last) 24-Sep-2020
+* @author  (last)      Sean Nash
+* @date    (last)      13-Aug-2021
 *
-* @author (original) Dara Navaei
-* @date (original) 05-Nov-2019
+* @author  (original)  Dara Navaei
+* @date    (original)  05-Nov-2019
 *
 ***************************************************************************/
 
@@ -49,6 +49,7 @@
 static U32 broadcastModeIntervalCtr = 11;                   ///< Interval counter used to determine when to broadcast operation mode.  Initialize to 11 to stagger broadcast.
 /// Interval (in task intervals) at which to publish operation mode data to CAN bus.
 static OVERRIDE_U32_T opModePublishInterval = { BROADCAST_HD_OP_MODE_INTERVAL, BROADCAST_HD_OP_MODE_INTERVAL, BROADCAST_HD_OP_MODE_INTERVAL, 0 };
+static U32 priorSubMode = 0;                                ///< The prior submode state.
 
 /// This matrix determines legal transitions from one mode to another
 static const HD_OP_MODE_T MODE_TRANSITION_TABLE[ NUM_OF_MODES - 1 ][ NUM_OF_MODES - 1 ] = {
@@ -88,6 +89,7 @@
     // Start in init mode
     currentMode = MODE_INIT;
     currentSubMode = 0;
+    priorSubMode = 0;
     transitionToNewOperationMode( MODE_INIT );
 
     // Call initializers for the individual modes
@@ -112,6 +114,8 @@
 {
     HD_OP_MODE_T newMode;
 
+    priorSubMode = currentSubMode;
+
     // Any new mode requests?
     newMode = arbitrateModeRequest();   // Will return current mode if no pending requests
     newMode = MODE_TRANSITION_TABLE[ currentMode ][ newMode ];
@@ -174,6 +178,13 @@
             break;
     }   // End switch
 
+    // Send sub-mode change event when appropriate
+    if ( priorSubMode != currentSubMode )
+    {
+        SEND_EVENT_WITH_2_U32_DATA( HD_EVENT_SUB_MODE_CHANGE, priorSubMode, currentSubMode )
+    }
+    priorSubMode = currentSubMode;
+
     // Broadcast current operation mode on interval
     broadcastOperationMode();
 }
@@ -317,37 +328,43 @@
  *************************************************************************/
 static void transitionToNewOperationMode( HD_OP_MODE_T newMode )
 {
+    SEND_EVENT_WITH_2_U32_DATA( HD_EVENT_OP_MODE_CHANGE, lastMode, newMode )
+
     // Setup for new operating mode
     switch ( newMode )
     {
         case MODE_FAUL:
-            transitionToFaultMode();
+            currentSubMode = transitionToFaultMode();
             break;
         case MODE_SERV:
-            transitionToServiceMode();
+            currentSubMode = transitionToServiceMode();
             break;
         case MODE_INIT:
-            transitionToInitAndPOSTMode();
+            currentSubMode = transitionToInitAndPOSTMode();
             break;
         case MODE_STAN:
-            transitionToStandbyMode();
+            currentSubMode = transitionToStandbyMode();
             break;
         case MODE_TPAR:
-            transitionToTreatParamsMode();
+            currentSubMode = transitionToTreatParamsMode();
             break;
         case MODE_PRET:
-            transitionToPreTreatmentMode();
+            currentSubMode = transitionToPreTreatmentMode();
             break;
         case MODE_TREA:
-            transitionToTreatmentMode();
+            currentSubMode = transitionToTreatmentMode();
             break;
         case MODE_POST:
-            transitionToPostTreatmentMode();
+            currentSubMode = transitionToPostTreatmentMode();
             break;
         default:
             SET_ALARM_WITH_2_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_OP_MODES_INVALID_MODE_TO_TRANSITION_TO, newMode )
             break;
     }
+
+    SEND_EVENT_WITH_2_U32_DATA( HD_EVENT_SUB_MODE_CHANGE, priorSubMode, currentSubMode )
+
+    priorSubMode = currentSubMode;
 }
 
 /*********************************************************************//**
@@ -362,8 +379,12 @@
 {
     if ( ++broadcastModeIntervalCtr >= getU32OverrideValue( &opModePublishInterval ) )
     {
+        OP_MODE_PAYLOAD_T data;
+
         broadcastModeIntervalCtr = 0;
-        broadcastHDOperationMode( (U32)currentMode, currentSubMode );
+        data.opMode = (U32)currentMode;
+        data.subMode = currentSubMode;
+        broadcastData( MSG_ID_HD_OP_MODE, COMM_BUFFER_OUT_CAN_HD_BROADCAST, (U08*)&data, sizeof( OP_MODE_PAYLOAD_T ) );
     }
 }