Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r67731d57db9a620418b3b848d8f75ff204902c36 -r6d4aa77e6b85aa7621a234660f631e725fb1d441
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 67731d57db9a620418b3b848d8f75ff204902c36)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 6d4aa77e6b85aa7621a234660f631e725fb1d441)
@@ -1,30 +1,33 @@
 /**************************************************************************
 *
-* Copyright (c) 2024-2024 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2024-2026 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    ModeStandby.c
 *
-* @author  (last)      Vinayakam Mani
-* @date    (last)      06-Aug-2024
+* @author  (last)      Raghu Kallala
+* @date    (last)      22-Apr-2026
 *
 * @author  (original)  Vinayakam Mani
-* @date    (original)  06-Aug-2024
+* @date    (original)  07-Aug-2024
 *
 ***************************************************************************/
 
 #include "BalancingChamber.h"
 #include "ConcentratePumps.h"
 #include "ConductivitySensors.h"
+#include "FPOperationModes.h"
 #include "Heaters.h"
 #include "ModeFault.h"
 #include "ModeStandby.h"
+#include "ModeGenDialysate.h"
 #include "MessageSupport.h"
 #include "Messaging.h"
 //#include "NVDataMgmt.h"
 #include "OperationModes.h"
+#include "PermeateTank.h"
 #include "Pressure.h"
 #include "SystemCommDD.h"
 #include "TaskGeneral.h"
@@ -44,7 +47,6 @@
 static DD_STANDBY_MODE_STATE_T standbyState;                                              ///< Currently active standby state.
 
 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.
@@ -66,7 +68,6 @@
 {
     standbyState                                 = DD_STANDBY_MODE_STATE_IDLE;
     pendingStartDDPreGenRequest                  = FALSE;
-    pendingBalanceChamberSwOnlyRequest           = FALSE;
 //    pendingStartDDFlushRequest                   = FALSE;
 //    pendingStartDDHeatDisinfectRequest           = FALSE;
 //    pendingStartDDHeatDisinfectActiveCoolRequest = FALSE;
@@ -90,6 +91,11 @@
 
     deenergizeActuators( PARK_CONC_PUMPS );
 
+    resetPermeateTank();
+
+    // Deactivate Balancing Chamber Switching
+    requestBalChamberSwitching( FALSE );
+
 //    // 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( D17_COND, CAL_DATA_CD1_COND_SENSOR );
@@ -153,6 +159,7 @@
 static DD_STANDBY_MODE_STATE_T handleStandbyIdleState( void )
 {
     DD_STANDBY_MODE_STATE_T state = DD_STANDBY_MODE_STATE_IDLE;
+    FP_OP_MODE_T fpMode = getCurrentFPOperationMode();
 
     //TODO : Define comm loss alarm when TD is turned off or stops communicating
 //    if ( FALSE == isTDCommunicating() )
@@ -161,14 +168,18 @@
 //    }
     if ( TRUE == pendingStartDDPreGenRequest )
     {
-        pendingStartDDPreGenRequest = FALSE;
-        requestNewOperationMode( DD_MODE_PREG );
+       // wait for IOFP GENP mode and when IOFP manual control is not set
+       if ( ( ( FP_MODE_GENP == fpMode ) ||  ( FP_MODE_DEGP == fpMode ) ) && ( getTestConfigStatus( TEST_CONFIG_DD_RUN_SOLO ) == FALSE ) )
+       {
+           pendingStartDDPreGenRequest = FALSE;
+           requestNewOperationMode( DD_MODE_PREG );
+       }
+       else if ( getTestConfigStatus( TEST_CONFIG_DD_RUN_SOLO ) == TRUE )
+       {
+           pendingStartDDPreGenRequest = FALSE;
+           requestNewOperationMode( DD_MODE_PREG );
+       }
     }
-    //Test request to handle only balancing chamber switching
-    else if ( TRUE == pendingBalanceChamberSwOnlyRequest )
-    {
-        execBalancingChamberControl();
-    }
 //    else if ( TRUE == pendingStartDDFlushRequest )
 //    {
 //        pendingStartDDFlushRequest = FALSE;
@@ -234,7 +245,7 @@
  * The requestBCSwitchingOnlyStart function handles Balancing chamber switching
  * only start request.
  * @details \b Inputs: standbyState
- * @details \b Outputs: pendingBalanceChamberSwOnlyRequest
+ * @details \b Outputs: none
  * @return TRUE if request accepted, FALSE if not.
  *************************************************************************/
 BOOL requestBCSwitchingOnlyStart( void )
@@ -244,7 +255,9 @@
     if ( DD_STANDBY_MODE_STATE_IDLE == standbyState )
     {
         result                             = TRUE;
-        pendingBalanceChamberSwOnlyRequest = TRUE;
+
+        // Activate Balancing Chamber Switching
+        requestBalChamberSwitching( TRUE );
     }
 
     return result;
@@ -255,12 +268,14 @@
  * The requestBCSwitchingOnlyStop function handles Balancing chamber switching
  * only stop request.
  * @details \b Inputs: standbyState
- * @details \b Outputs: pendingBalanceChamberSwOnlyRequest
+ * @details \b Outputs: none
  * @return none.
  *************************************************************************/
 void requestBCSwitchingOnlyStop( void )
 {
-    pendingBalanceChamberSwOnlyRequest = FALSE;
+    // Deactivate Balancing Chamber Switching
+    requestBalChamberSwitching( FALSE );
+
     // Close all balancing chamber valves
     valveControlForBCClosedState();
 }
@@ -464,4 +479,60 @@
  *************************************************************************/
 
 
+/*********************************************************************//**
+ * @brief
+ * The testValidateDDStandbyChangeReq function validate whether request
+ * operation sub mode is legal or not.
+ * @details \b Inputs: none
+ * @details \b Outputs: none
+ * @param newSubMode the enumerated sub state of the mode
+ * @return TRUE if request is legal, FALSE if not
+ *************************************************************************/
+BOOL testValidateDDStandbyChangeReq( U32 newSubMode )
+{
+    BOOL result = FALSE;
+
+    if ( newSubMode < NUM_OF_DD_STANDBY_MODE_STATES )
+    {
+        switch ( newSubMode )
+        {
+            case DD_STANDBY_MODE_STATE_IDLE:
+                result = TRUE;
+                break;
+
+            case DD_STANDBY_MODE_STATE_PAUSE:
+            default:
+                break;
+        }
+    }
+
+    return result;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The testSignalNewDDStandbySubMode function request transition to a
+ * new operation sub mode.
+ * @details \b Inputs: none
+ * @details \b Outputs: standbyState
+ * @param newSubMode the enumerated sub state of the mode
+ * @return none
+ *************************************************************************/
+void testSignalNewDDStandbySubMode( U32 newSubMode )
+{
+    if ( newSubMode < NUM_OF_DD_STANDBY_MODE_STATES )
+    {
+        standbyState = (DD_STANDBY_MODE_STATE_T)newSubMode;
+
+        switch ( newSubMode )
+        {
+            // Any of these state require no special handling
+            case DD_STANDBY_MODE_STATE_IDLE:
+            case DD_STANDBY_MODE_STATE_PAUSE:
+            default:
+                break;
+        }
+    }
+}
+
 /**@}*/