Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r6679a2cd813b21a8cb4c58b3eeb721e0eef9a10b -r67731d57db9a620418b3b848d8f75ff204902c36
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 6679a2cd813b21a8cb4c58b3eeb721e0eef9a10b)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 67731d57db9a620418b3b848d8f75ff204902c36)
@@ -15,6 +15,7 @@
 *
 ***************************************************************************/
 
+#include "BalancingChamber.h"
 #include "ConcentratePumps.h"
 #include "ConductivitySensors.h"
 #include "Heaters.h"
@@ -42,7 +43,8 @@
 
 static DD_STANDBY_MODE_STATE_T standbyState;                                              ///< Currently active standby state.
 
-static OVERRIDE_U32_T pendingStartDDRequest;                                              ///< Flag indicating TD has requested DD start the dialysis delivery(Overridable).
+static BOOL pendingStartDDPreGenRequest;                                                  ///< Flag indicating TD has requested DD start the pre generation dialysate request.
+static BOOL pendingBalanceChamberSwOnlyRequest;                                           ///< Flag indicating balancing chamber switch only request.
 //static BOOL pendingStartDDFlushRequest;                                                 ///< Flag indicating TD has requested DD start flush.
 //static BOOL pendingStartDDHeatDisinfectRequest;                                         ///< Flag indicating TD has requested DD start heat disinfect.
 //static BOOL pendingStartDDHeatDisinfectActiveCoolRequest;                               ///< Flag indicating TD has requested DD start heat disinfect active cool.
@@ -63,10 +65,8 @@
 void initStandbyMode( void )
 {
     standbyState                                 = DD_STANDBY_MODE_STATE_IDLE;
-    pendingStartDDRequest.data                   = FALSE;
-    pendingStartDDRequest.ovData                 = FALSE;
-    pendingStartDDRequest.ovInitData             = FALSE;
-    pendingStartDDRequest.override               = OVERRIDE_RESET;
+    pendingStartDDPreGenRequest                  = FALSE;
+    pendingBalanceChamberSwOnlyRequest           = FALSE;
 //    pendingStartDDFlushRequest                   = FALSE;
 //    pendingStartDDHeatDisinfectRequest           = FALSE;
 //    pendingStartDDHeatDisinfectActiveCoolRequest = FALSE;
@@ -92,8 +92,8 @@
 
 //    // Upon transition to mode standby set CD1 and CD2 calibration records to be picked to the normal
 //    // table. If the chemical disinfect fails, the mode transitions back to mode standby.
-//    setCondcutivitySensorCalTable( CONDUCTIVITYSENSORS_CD1_SENSOR, CAL_DATA_CD1_COND_SENSOR );
-//    setCondcutivitySensorCalTable( CONDUCTIVITYSENSORS_CD2_SENSOR, CAL_DATA_CD2_COND_SENSOR );
+//    setCondcutivitySensorCalTable( D17_COND, CAL_DATA_CD1_COND_SENSOR );
+//    setCondcutivitySensorCalTable( D27_COND, CAL_DATA_CD2_COND_SENSOR );
 //
 //
     // Send DD usage data to TD
@@ -116,11 +116,6 @@
  *************************************************************************/
 U32 execStandbyMode( void )
 {
-    if ( TRUE == areInletWaterConditionsAlarmsActive() )
-    {
-        standbyState = DD_STANDBY_MODE_STATE_PAUSE;
-    }
-
     // execute current Standby state
     switch ( standbyState )
     {
@@ -143,33 +138,9 @@
 
 /*********************************************************************//**
  * @brief
- * The areInletWaterConditionsAlarmsActive function checks whether the inlet
- * water pressure conditions are out of range and any of their alarms are active.
- * @details \b Inputs: Input and Output pressure of water inlet pressur regulator.
- * @details \b Outputs: None
- * @return TRUE if any of the alarms are active, otherwise, FALSE
- *************************************************************************/
-BOOL areInletWaterConditionsAlarmsActive( void )
-{
-    BOOL status = FALSE;
-
-    // Check Inlet Water Pressure - both Water inlet pressure Input, pressure Output after pressure regulator.
-    checkInletWaterPressure();
-
-    // Check any active alarms
-    status |= isAlarmActive( ALARM_ID_DD_INLET_WATER_PRESSURE_OUT_LOW_RANGE );
-    status |= isAlarmActive( ALARM_ID_DD_INLET_WATER_PRESSURE_OUT_HIGH_RANGE );
-    status |= isAlarmActive( ALARM_ID_DD_INLET_WATER_PRESSURE_IN_HIGH_RANGE );
-    status |= isAlarmActive( ALARM_ID_DD_INLET_WATER_PRESSURE_IN_LOW_RANGE );
-
-    return status;
-}
-
-/*********************************************************************//**
- * @brief
  * The handleStandbyIdleState function executes the idle state of the
  * standby mode state machine.
- * @details \b Inputs: pendingSampleWaterRequest, pendingStartDDRequest,
+ * @details \b Inputs: pendingSampleWaterRequest, pendingStartDDPreGenRequest,
  * pendingStartDDFlushRequest, pendingStartDDHeatDisinfectRequest,
  * pendingStartDDChemicalDisinfectRequest
  * @details \b Outputs: Idle state of the standby mode executed,
@@ -183,16 +154,20 @@
 {
     DD_STANDBY_MODE_STATE_T state = DD_STANDBY_MODE_STATE_IDLE;
 
-    // go to standby solo mode if TD is turned off or stops communicating.
-    if ( FALSE == isTDCommunicating() )
-    {   // TODO if TD comm loss, do we need solo standby?
-        SEND_EVENT_WITH_2_U32_DATA( DD_EVENT_TD_COMMUNICATION_LOSS, 0, 0 )
-        //requestNewOperationMode( DD_MODE_SOLO );
+    //TODO : Define comm loss alarm when TD is turned off or stops communicating
+//    if ( FALSE == isTDCommunicating() )
+//    {
+            // define the alarm
+//    }
+    if ( TRUE == pendingStartDDPreGenRequest )
+    {
+        pendingStartDDPreGenRequest = FALSE;
+        requestNewOperationMode( DD_MODE_PREG );
     }
-    else if ( TRUE == getU32OverrideValue( &pendingStartDDRequest ) )
+    //Test request to handle only balancing chamber switching
+    else if ( TRUE == pendingBalanceChamberSwOnlyRequest )
     {
-        pendingStartDDRequest.data = FALSE;
-        requestNewOperationMode( DD_MODE_GEND );
+        execBalancingChamberControl();
     }
 //    else if ( TRUE == pendingStartDDFlushRequest )
 //    {
@@ -230,36 +205,68 @@
 {
     DD_STANDBY_MODE_STATE_T state = DD_STANDBY_MODE_STATE_PAUSE;
 
-    if ( FALSE == areInletWaterConditionsAlarmsActive() )
+    return state;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The requestDDPreGenStart function handles an TD request to start/
+ * go to pre generation dialysis mode.
+ * @details \b Inputs: standbyState
+ * @details \b Outputs: pendingStartDDPreGenRequest
+ * @return TRUE if request accepted, FALSE if not.
+ *************************************************************************/
+BOOL requestDDPreGenStart( void )
+{
+    BOOL result = FALSE;
+
+    if ( DD_STANDBY_MODE_STATE_IDLE == standbyState )
     {
-        state = DD_STANDBY_MODE_STATE_IDLE;
+        result                           = TRUE;
+        pendingStartDDPreGenRequest      = TRUE;
     }
 
-    return state;
+    return result;
 }
 
 /*********************************************************************//**
  * @brief
- * The requestDDStart function handles an TD request to start (go to generation dialysis mode).
+ * The requestBCSwitchingOnlyStart function handles Balancing chamber switching
+ * only start request.
  * @details \b Inputs: standbyState
- * @details \b Outputs: pendingStartDDRequest
+ * @details \b Outputs: pendingBalanceChamberSwOnlyRequest
  * @return TRUE if request accepted, FALSE if not.
  *************************************************************************/
-BOOL requestDDStart( void )
+BOOL requestBCSwitchingOnlyStart( void )
 {
     BOOL result = FALSE;
 
     if ( DD_STANDBY_MODE_STATE_IDLE == standbyState )
     {
-        result                     = TRUE;
-        pendingStartDDRequest.data = TRUE;
+        result                             = TRUE;
+        pendingBalanceChamberSwOnlyRequest = TRUE;
     }
 
     return result;
 }
 
 /*********************************************************************//**
  * @brief
+ * The requestBCSwitchingOnlyStop function handles Balancing chamber switching
+ * only stop request.
+ * @details \b Inputs: standbyState
+ * @details \b Outputs: pendingBalanceChamberSwOnlyRequest
+ * @return none.
+ *************************************************************************/
+void requestBCSwitchingOnlyStop( void )
+{
+    pendingBalanceChamberSwOnlyRequest = FALSE;
+    // Close all balancing chamber valves
+    valveControlForBCClosedState();
+}
+
+/*********************************************************************//**
+ * @brief
  * The startDDFlush function starts DD flush mode.
  * @details \b Inputs: standbyState
  * @details \b Outputs: none
@@ -457,21 +464,4 @@
  *************************************************************************/
 
 
-/*********************************************************************//**
- * @brief
- * The testDDstartGenDialysateOverride function sets the override value
- * to start the gen dialysate operation mode.
- * @details Inputs: pendingStartDDRequest
- * @details Outputs: pendingStartDDRequest
- * @param message Override message from Dialin which includes the flag
- * to override the operation mode.
- * @return TRUE if override successful, FALSE if not
- *************************************************************************/
-BOOL testDDstartGenDialysateOverride( MESSAGE_T *message )
-{
-    BOOL result = u32Override( message, &pendingStartDDRequest, FALSE, TRUE );
-
-    return result;
-}
-
 /**@}*/