Index: firmware/App/Modes/ModeChemicalDisinfect.c
===================================================================
diff -u -r5315092604c1a6f4ec8ba1339809bd0099f921da -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeChemicalDisinfect.c	(.../ModeChemicalDisinfect.c)	(revision 5315092604c1a6f4ec8ba1339809bd0099f921da)
+++ firmware/App/Modes/ModeChemicalDisinfect.c	(.../ModeChemicalDisinfect.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -293,7 +293,7 @@
     deenergizeActuators( NO_PARK_CONC_PUMPS );
 
     initChemicalDisinfectMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_YELLOW );
 
 #ifndef _RELEASE_
Index: firmware/App/Modes/ModeChemicalDisinfectFlush.c
===================================================================
diff -u -r5315092604c1a6f4ec8ba1339809bd0099f921da -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeChemicalDisinfectFlush.c	(.../ModeChemicalDisinfectFlush.c)	(revision 5315092604c1a6f4ec8ba1339809bd0099f921da)
+++ firmware/App/Modes/ModeChemicalDisinfectFlush.c	(.../ModeChemicalDisinfectFlush.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -197,7 +197,7 @@
     deenergizeActuators( NO_PARK_CONC_PUMPS );
 
     initChemicalDisinfectFlushMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_YELLOW );
 
     activateAlarmNoData( ALARM_ID_DG_CHEM_DISINFECT_FLUSH_REMOVE_ACID );
Index: firmware/App/Modes/ModeDrain.c
===================================================================
diff -u -r67da3f0d10e1143173b1e8c29061097d609d8623 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeDrain.c	(.../ModeDrain.c)	(revision 67da3f0d10e1143173b1e8c29061097d609d8623)
+++ firmware/App/Modes/ModeDrain.c	(.../ModeDrain.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -113,6 +113,7 @@
 {
     // re-initialize each time we transition to drain mode
     initDrainMode();
+    setCurrentSubState( NO_SUB_STATE );
 
     DG_RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();
 
Index: firmware/App/Modes/ModeFault.c
===================================================================
diff -u -r56ba1b163b0cbf6953638065b2108f745b17ec8f -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeFault.c	(.../ModeFault.c)	(revision 56ba1b163b0cbf6953638065b2108f745b17ec8f)
+++ firmware/App/Modes/ModeFault.c	(.../ModeFault.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -75,7 +75,7 @@
     deenergizeActuators( PARK_CONC_PUMPS );
 
     initFaultMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     // Publish POST failure status to UI if fault triggered in Init/POST mode
     if ( DG_MODE_INIT == getPreviousOperationMode() )
     {
Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rc7ea3969643ead419cbfcd34c3cb203c45bcad71 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision c7ea3969643ead419cbfcd34c3cb203c45bcad71)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -217,7 +217,7 @@
 U32 transitionToFillMode( void )
 {
     initFillMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     // Set initial actuator states
     setValveState( VDR, VALVE_STATE_DRAIN_C_TO_NO );
     setValveState( VPO, VALVE_STATE_NOFILL_C_TO_NO );
Index: firmware/App/Modes/ModeFlush.c
===================================================================
diff -u -re12f1b3d41ae133bc0975fcb126e431c2bedda59 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeFlush.c	(.../ModeFlush.c)	(revision e12f1b3d41ae133bc0975fcb126e431c2bedda59)
+++ firmware/App/Modes/ModeFlush.c	(.../ModeFlush.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -171,7 +171,7 @@
     deenergizeActuators( NO_PARK_CONC_PUMPS );
 
     initFlushMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_BLUE );
 
     return flushState;
Index: firmware/App/Modes/ModeGenIdle.c
===================================================================
diff -u -r5315092604c1a6f4ec8ba1339809bd0099f921da -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeGenIdle.c	(.../ModeGenIdle.c)	(revision 5315092604c1a6f4ec8ba1339809bd0099f921da)
+++ firmware/App/Modes/ModeGenIdle.c	(.../ModeGenIdle.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -104,7 +104,7 @@
 {
     // Re-initialize each time we transition to generation idle mode
     initGenIdleMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     // Set initial actuator states
     setValveState( VSP, VALVE_STATE_CLOSED );
     setValveState( VPI, VALVE_STATE_OPEN );
@@ -286,6 +286,7 @@
 static DG_GEN_IDLE_MODE_STATE_T handleBadFillState( void )
 {
     DG_GEN_IDLE_MODE_STATE_T result = DG_GEN_IDLE_MODE_STATE_HANDLE_BAD_FILL;
+    U32 priorSubState = badFillState;
 
     // Execute current bad fill state
     switch ( badFillState )
@@ -316,6 +317,10 @@
             break;
     }
 
+    if ( priorSubState != badFillState )
+    {
+        setCurrentSubState( badFillState );
+    }
     return result;
 }
 
Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -r5315092604c1a6f4ec8ba1339809bd0099f921da -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 5315092604c1a6f4ec8ba1339809bd0099f921da)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -318,7 +318,7 @@
     deenergizeActuators( NO_PARK_CONC_PUMPS );
 
     initHeatDisinfectMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_ORANGE );
 
     return heatDisinfectState;
Index: firmware/App/Modes/ModeHeatDisinfectActiveCool.c
===================================================================
diff -u -re12f1b3d41ae133bc0975fcb126e431c2bedda59 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeHeatDisinfectActiveCool.c	(.../ModeHeatDisinfectActiveCool.c)	(revision e12f1b3d41ae133bc0975fcb126e431c2bedda59)
+++ firmware/App/Modes/ModeHeatDisinfectActiveCool.c	(.../ModeHeatDisinfectActiveCool.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -177,7 +177,7 @@
     deenergizeActuators( NO_PARK_CONC_PUMPS );
 
     initHeatDisinfectActiveCoolMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_ORANGE );
 
     return heatDisinfectActiveCoolState;
Index: firmware/App/Modes/ModeInitPOST.c
===================================================================
diff -u -r0ee5103ebceb698eadac7b18398471361811a151 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeInitPOST.c	(.../ModeInitPOST.c)	(revision 0ee5103ebceb698eadac7b18398471361811a151)
+++ firmware/App/Modes/ModeInitPOST.c	(.../ModeInitPOST.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -95,7 +95,7 @@
 {
     initInitAndPOSTMode();
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_OFF );
-
+    setCurrentSubState( NO_SUB_STATE );
     resetRTCPOSTState();
     resetNVDataMgmtPOSTState();
     resetAccelPOSTState();
Index: firmware/App/Modes/ModeService.c
===================================================================
diff -u -r6499ea25921fcf67826fa0c35bb03caf411ba542 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeService.c	(.../ModeService.c)	(revision 6499ea25921fcf67826fa0c35bb03caf411ba542)
+++ firmware/App/Modes/ModeService.c	(.../ModeService.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -58,7 +58,7 @@
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_OFF );
     deenergizeActuators( NO_PARK_CONC_PUMPS );
     initServiceMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     return serviceState;
 }
 
Index: firmware/App/Modes/ModeSolo.c
===================================================================
diff -u -r6499ea25921fcf67826fa0c35bb03caf411ba542 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/ModeSolo.c	(.../ModeSolo.c)	(revision 6499ea25921fcf67826fa0c35bb03caf411ba542)
+++ firmware/App/Modes/ModeSolo.c	(.../ModeSolo.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -57,7 +57,7 @@
 U32 transitionToSoloMode( void )
 {
     initSoloMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_OFF );
 
     return soloState;
Index: firmware/App/Modes/OperationModes.c
===================================================================
diff -u -rc230be1bd4296324bf5dfc288c212eb7c2ce5d2d -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision c230be1bd4296324bf5dfc288c212eb7c2ce5d2d)
+++ firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -57,6 +57,7 @@
 /// DG operation mode data publish interval.
 static OVERRIDE_U32_T dgOpModePublishInterval = { BROADCAST_DG_OP_MODE_INTERVAL, BROADCAST_DG_OP_MODE_INTERVAL, 0, 0 };
 static U32 dataPublishCounter;                                                      ///< Interval counter used to determine when to broadcast operation mode.  Initialize to 11 to stagger broadcast.
+static U32 currentSubState;                                                         ///< The currently active sub state.
 
 /// This matrix determines legal transitions from one mode to another.
 static const DG_OP_MODE_T MODE_TRANSITION_TABLE[ NUM_OF_DG_MODES - 1 ][ NUM_OF_DG_MODES - 1 ] =
@@ -83,6 +84,7 @@
 static void transitionToNewOperationMode( DG_OP_MODE_T newMode );
 static U32  getDGOpModePublishInterval( void );
 static void broadcastOperationMode( void );
+static void sendOperationStatusEvent( void );
 
 /*********************************************************************//**
  * @brief
@@ -106,6 +108,7 @@
     lastMode           = DG_MODE_INIT;
     currentMode        = DG_MODE_INIT;
     currentSubMode     = 0;
+    currentSubState    = 0xFF;
     dataPublishCounter = DATA_PUBLISH_COUNTER_START_COUNT;
 
     transitionToNewOperationMode( DG_MODE_INIT );
@@ -137,6 +140,8 @@
 {
     DG_OP_MODE_T newMode;
     U32 priorSubMode = currentSubMode;
+    U32 priorOpMode =  currentMode;
+    U32 priorSubState = currentSubState;
 
     // any new mode requests?
     newMode = arbitrateModeRequest();   // will return current mode if no pending requests
@@ -220,9 +225,10 @@
             break;
     }
 
-    // Send sub-mode change event when appropriate
-    if ( priorSubMode != currentSubMode )
+    // Send operation status event when appropriate
+    if ( priorOpMode != currentMode || priorSubMode != currentSubMode || priorSubState != currentSubState )
     {
+        sendOperationStatusEvent();
         SEND_EVENT_WITH_2_U32_DATA( DG_EVENT_SUB_MODE_CHANGE, priorSubMode, currentSubMode )
     }
 
@@ -426,7 +432,47 @@
     return result;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The setCurrentSubState function sets the current subState.
+ * @details Inputs: subState
+ * @details Outputs: currentSubState
+ * @param subState the enumerated sub state.
+ * @return none
+ *************************************************************************/
+void setCurrentSubState( U32 subState )
+{
+    currentSubState = subState;
+}
 
+/*********************************************************************//**
+ * @brief
+ * The sendOperationStatusEvent function constructs and sends an DG operation
+ * status event.
+ * @details Inputs: currentMode, currentSubMode, currentSubState
+ * @details Outputs: dat1, dat2.
+ * @param none
+ * @return none
+ *************************************************************************/
+static void sendOperationStatusEvent()
+{
+
+    EVENT_DATA_T dat1;
+    EVENT_DATA_T dat2;
+    U32 opData = ( (U08)currentMode +
+                 ( (U08)currentSubMode << SHIFT_8_BITS_FOR_BYTE_SHIFT ) +
+                 ( (U08)currentSubState << SHIFT_16_BITS_FOR_WORD_SHIFT ) );
+
+    dat2.dataType = EVENT_DATA_TYPE_U32;
+    dat2.data.uInt.data = 0;
+
+    dat1.dataType = EVENT_DATA_TYPE_U32;
+    dat1.data.uInt.data = opData;
+
+    sendEvent( DG_EVENT_OPERATION_STATUS, dat1, dat2 );
+}
+
+
 /*************************************************************************
  *                       TEST SUPPORT FUNCTIONS
  *************************************************************************/
Index: firmware/App/Modes/OperationModes.h
===================================================================
diff -u -r6499ea25921fcf67826fa0c35bb03caf411ba542 -rd19a072db6880577f677093929b53445e34a33e3
--- firmware/App/Modes/OperationModes.h	(.../OperationModes.h)	(revision 6499ea25921fcf67826fa0c35bb03caf411ba542)
+++ firmware/App/Modes/OperationModes.h	(.../OperationModes.h)	(revision d19a072db6880577f677093929b53445e34a33e3)
@@ -31,6 +31,8 @@
 
 // ********** public definitions **********
 
+#define NO_SUB_STATE    0xFF ///< value for when submode does not have specific substates and is not applicable.
+
 /// Operation modes data structure
 typedef struct
 {
@@ -45,6 +47,7 @@
 void requestNewOperationMode( DG_OP_MODE_T newMode );   // request a transition to a new operation mode
 DG_OP_MODE_T getCurrentOperationMode( void );           // get the current operation mode
 DG_OP_MODE_T getPreviousOperationMode( void );          // get the previous operation mode
+void setCurrentSubState( U32 subState );                            // Set the current substate.
 
 BOOL testSetOperationMode( DG_OP_MODE_T newMode );      // Force transition to a given mode (if allowed)
 BOOL testSetDGOpModePublishIntervalOverride( U32 value );