Index: firmware/App/Controllers/DryBiCart.c
===================================================================
diff -u -rc0e1f5f4c4657c156a87cc8be6c3db38bb14db33 -r05ab87b4de779f06243fa1e87a0402b659a6fa3e
--- firmware/App/Controllers/DryBiCart.c	(.../DryBiCart.c)	(revision c0e1f5f4c4657c156a87cc8be6c3db38bb14db33)
+++ firmware/App/Controllers/DryBiCart.c	(.../DryBiCart.c)	(revision 05ab87b4de779f06243fa1e87a0402b659a6fa3e)
@@ -24,6 +24,7 @@
 #include "DryBiCart.h"
 #include "Level.h"
 #include "Messaging.h"
+#include "MessageSupport.h"
 #include "MixingControl.h"
 #include "ModeGenDialysate.h"
 #include "OperationModes.h"
@@ -144,6 +145,8 @@
 static BOOL dryBiCartPressureDecayStartTimeFlag;                                                ///< Dry bicart d66 pressure decay start timer.
 static DRY_BICART_OPERATION_T dryBicartStartRequest;                                            ///< Dry bicart operation, fill or supply or drain request
 
+static DRY_BICART_OPERATION_T prevDryBicartState;                                               ///< Dry BiCart State Change Tracker
+
 // ********** private function prototypes **********
 
 static void updateDrybicartOperation(void);
@@ -250,6 +253,7 @@
     dryBiCartDrainTimePeriod                            = 0;
     dryBiCartPersistenceStartTime                       = 0;
     drybicartPersistenceOnLowercartPressureStartTime    = 0;
+    prevDryBicartState                                  = DRY_BICART_IDLE;
 }
 
 /*********************************************************************//**
@@ -269,8 +273,8 @@
  * @brief
  * The execDryBicart function executes the set of dry bicarbonate cartridge fill,
  * bicarbonate chamber fill and bicarbonate cartridge drain related state machines one at time
- * @details \b Inputs: dryBicartStartRequest
- * @details \b Outputs: none
+ * @details \b Inputs: dryBicartStartRequest, prevDryBicartState
+ * @details \b Outputs: prevDryBicartState
  * @details \b Alarm: ALARM_ID_DD_SOFTWARE_FAULT when wrong dry bicart state machine is
  * invoked.
  * @return none.
@@ -314,6 +318,12 @@
             break;
     }
 
+    if ( prevDryBicartState != dryBicartStartRequest )
+    {
+        SEND_EVENT_WITH_2_U32_DATA( DD_EVENT_DRY_BICART_STATE_CHANGE, prevDryBicartState, dryBicartStartRequest );
+        prevDryBicartState = dryBicartStartRequest;
+    }
+
     // Publish dry bicart data
     publishDryBicartData();
 }