Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -ra7c2d1b211a6698c45a1d5a1c64d261e78b4f895 -r7d4711edd7b40cd3e29f43e766f79a8a09586fe9
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision a7c2d1b211a6698c45a1d5a1c64d261e78b4f895)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 7d4711edd7b40cd3e29f43e766f79a8a09586fe9)
@@ -1,14 +1,14 @@
 /**************************************************************************
 *
-* Copyright (c) 2019-2023 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2019-2024 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)      Sean Nash
-* @date    (last)      18-Jul-2023
+* @author  (last)      Dara Navaei
+* @date    (last)      10-Nov-2023
 *
 * @author  (original)  Dara Navaei
 * @date    (original)  05-Nov-2019
@@ -122,6 +122,8 @@
  *************************************************************************/
 U32 transitionToStandbyMode( void )
 {
+    MESSAGE_T usageMsg;
+
     // re-initialize standby mode each time we transition to standby mode
     initStandbyMode();
 
@@ -143,6 +145,11 @@
     // This is to make sure the boolean flag for the first fill is set to TRUE.
     initReservoirs();
 
+    // Send DG usage data to HD
+    usageMsg.hdr.msgID = MSG_ID_HD_DG_USAGE_INFO_REQUEST;
+    usageMsg.hdr.payloadLen = 0;
+    handleHDRequestDGUsageInfo( &usageMsg );
+
     return standbyState;
 }
 
@@ -546,8 +553,9 @@
             concCap = STATE_CLOSED;
             diaCap  = STATE_CLOSED;
             // Using the caps switch to disable the chemical disinfect date checks
+            // This is for debug builds only to simulate that a chem flush has been done after chem
             usageInfo.lastChemDisFlushCompleteDateEpoch = 40;
-            usageInfo.lastChemDisCompleteDateEpoch      = 32;
+            usageInfo.lastChemDisStartDateEpoch         = 32;
         }
 #endif
 
@@ -557,7 +565,7 @@
             cmdResponse.rejectCode = ( STATE_OPEN == getSwitchStatus( DIALYSATE_CAP ) ? REQUEST_REJECT_REASON_DG_DIALYSATE_CAP_OPEN :
                                                                                         REQUEST_REJECT_REASON_DG_CONCENTRATE_CAP_OPEN );
         }
-        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisCompleteDateEpoch )
+        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisStartDateEpoch )
         {
             cmdResponse.rejected   = TRUE;
             cmdResponse.rejectCode = REQUEST_REJECT_REASON_DG_CHEM_FLUSH_NOT_COMPLETED;
@@ -605,8 +613,9 @@
             concCap = STATE_CLOSED;
             diaCap  = STATE_CLOSED;
             // Using the caps switch to disable the chemical disinfect date checks
+            // This is for debug builds only to simulate that a chem flush has been done after chem
             usageInfo.lastChemDisFlushCompleteDateEpoch = 40;
-            usageInfo.lastChemDisCompleteDateEpoch      = 32;
+            usageInfo.lastChemDisStartDateEpoch         = 32;
         }
 #endif
 
@@ -616,7 +625,7 @@
             cmdResponse.rejectCode = ( STATE_OPEN == getSwitchStatus( DIALYSATE_CAP ) ? REQUEST_REJECT_REASON_DG_DIALYSATE_CAP_OPEN :
                                                                                         REQUEST_REJECT_REASON_DG_CONCENTRATE_CAP_OPEN );
         }
-        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisCompleteDateEpoch )
+        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisStartDateEpoch )
         {
             cmdResponse.rejected   = TRUE;
             cmdResponse.rejectCode = REQUEST_REJECT_REASON_DG_CHEM_FLUSH_NOT_COMPLETED;
@@ -665,8 +674,9 @@
             concCap = STATE_CLOSED;
             diaCap  = STATE_CLOSED;
             // Using the caps switch to disable the chemical disinfect date checks
+            // This is for debug builds only to simulate that a chem flush has been done after chem
             usageInfo.lastChemDisFlushCompleteDateEpoch = 40;
-            usageInfo.lastChemDisCompleteDateEpoch      = 32;
+            usageInfo.lastChemDisStartDateEpoch         = 32;
         }
 #endif
 
@@ -676,7 +686,7 @@
             cmdResponse.rejectCode = ( STATE_OPEN == getSwitchStatus( DIALYSATE_CAP ) ? REQUEST_REJECT_REASON_DG_DIALYSATE_CAP_OPEN :
                                                                                         REQUEST_REJECT_REASON_DG_CONCENTRATE_CAP_OPEN );
         }
-        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisCompleteDateEpoch )
+        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisStartDateEpoch )
         {
             cmdResponse.rejected   = TRUE;
             cmdResponse.rejectCode = REQUEST_REJECT_REASON_DG_CHEM_FLUSH_NOT_COMPLETED;
@@ -813,14 +823,21 @@
     // If DG is in standby mode and the standby mode is in Idle, request RO permeate sample
     if ( ( DG_MODE_STAN == getCurrentOperationMode() ) && ( DG_STANDBY_MODE_STATE_IDLE == standbyState ) )
     {
+        DG_USAGE_INFO_RECORD_T usageInfo;
         OPN_CLS_STATE_T concCap = getSwitchStatus( CONCENTRATE_CAP );
         OPN_CLS_STATE_T diaCap  = getSwitchStatus( DIALYSATE_CAP );
 
+        getNVRecord2Driver( GET_USAGE_RECORD, (U08*)&usageInfo, sizeof( DG_USAGE_INFO_RECORD_T ), 0, ALARM_ID_NO_ALARM );
+
 #ifndef _RELEASE_
         if ( SW_CONFIG_ENABLE_VALUE == getSoftwareConfigStatus( SW_CONFIG_DISABLE_CAPS_MONITOR ) )
         {
             concCap = STATE_CLOSED;
             diaCap  = STATE_CLOSED;
+            // Using the caps switch to disable the chemical disinfect date checks.
+            // This is for debug builds only to simulate that a chem flush has been done after chem
+            usageInfo.lastChemDisFlushCompleteDateEpoch = 40;
+            usageInfo.lastChemDisStartDateEpoch         = 32;
         }
 #endif
 
@@ -830,6 +847,11 @@
             cmdResponse.rejectCode = ( STATE_OPEN == getSwitchStatus( DIALYSATE_CAP ) ? REQUEST_REJECT_REASON_DG_DIALYSATE_CAP_OPEN :
                                                                                         REQUEST_REJECT_REASON_DG_CONCENTRATE_CAP_OPEN );
         }
+        else if ( usageInfo.lastChemDisFlushCompleteDateEpoch < usageInfo.lastChemDisStartDateEpoch )
+        {
+            cmdResponse.rejected   = TRUE;
+            cmdResponse.rejectCode = REQUEST_REJECT_REASON_DG_CHEM_FLUSH_NOT_COMPLETED;
+        }
         else
         {
             pendingStartDGROPermeateSampleRequest = TRUE;