Index: firmware/App/Controllers/DryBiCart.c
===================================================================
diff -u -ra631e128cd6be44aa232e23b58a229bfb8fe9043 -r788a0b1a638d815df1e83af80cba7be03af2020c
--- firmware/App/Controllers/DryBiCart.c	(.../DryBiCart.c)	(revision a631e128cd6be44aa232e23b58a229bfb8fe9043)
+++ firmware/App/Controllers/DryBiCart.c	(.../DryBiCart.c)	(revision 788a0b1a638d815df1e83af80cba7be03af2020c)
@@ -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"
@@ -141,6 +142,31 @@
 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
 
+// drybicart mixing
+static OVERRIDE_F32_T dryBiCartAcidMixVolume;                                                   ///< Acid concentrate volume in ml ( overrideable).
+static OVERRIDE_F32_T dryBiCartBicarbMixVolume;                                                 ///< Bicarb concentrate volume in ml ( overrideable).
+
+static OVERRIDE_F32_T dryBiCartAcidMixVolumeKpGain;                                             ///< Acid kp gain.
+static OVERRIDE_F32_T dryBiCartAcidMixVolumeKiGain;                                             ///< Acid ki gain.
+
+static OVERRIDE_F32_T dryBiCartBicarbMixVolumeKpGain;                                           ///< Bicarb kp gain
+static OVERRIDE_F32_T dryBiCartBicarbMixVolumeKiGain;                                           ///< Acid ki gain.
+
+static DIALYSATE_MIXING_DATA_T dialysateMix[ NUM_OF_DIALYSATE_MIXING_ID ];                      ///< Array of dialysate mixing data structure.
+
+static OVERRIDE_F32_T dryBiCartBicarbTargetConductivity;                                        ///< Target bicarb conductivity
+static OVERRIDE_F32_T dryBiCartBicarbDeltaConductivity;                                         ///< Target delta conductivity
+
+static OVERRIDE_F32_T dryBiCartDialysateTargetConductivity;                                     ///< Acid bicarb mix conductivity
+static OVERRIDE_F32_T dryBiCartDialysateDeltaConductivity;                                      ///< Acid bicarb delta conductivity
+
+static OVERRIDE_U32_T dryBiCartMixControlInterval;                                              ///< Mix control interval
+
+static PI_CONTROLLER_SIGNALS_DATA bicarbControlSignals;                                         ///< Bicarb closed loop control signal data
+static PI_CONTROLLER_SIGNALS_DATA acidControlSignals;                                           ///< Acid closed loop control signal data
+
+static DRY_BICART_OPERATION_T prevDryBicartState;                                               ///< Last dry bicart operation prior to current state.
+
 // ********** private function prototypes **********
 
 static void updateDrybicartOperation(void);
@@ -245,8 +271,9 @@
     dryBiCartDrainLastCondSampleTime                    = 0;
     dryBiCartDrainCondStableCount                       = 0;
     dryBiCartDrainTimePeriod                            = 0;
-    dryBiCartPersistenceStartTime                       = 0;
+    dryBiCartPersistanceStartTime                       = 0;
     drybicartPersistenceOnLowercartPressureStartTime    = 0;
+    prevDryBicartState                                  = DRY_BICART_IDLE;
 }
 
 /*********************************************************************//**
@@ -266,8 +293,8 @@
  * @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.
@@ -311,6 +338,12 @@
             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();
 }