Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -rbdb9a1b636579c7bcfe95b329aa7e41ce161db13 -r30cbd9ff622e635f16df3801aabeb15dfaf5fff5
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision bdb9a1b636579c7bcfe95b329aa7e41ce161db13)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 30cbd9ff622e635f16df3801aabeb15dfaf5fff5)
@@ -76,7 +76,6 @@
 #define DELAY_FMP_CHECK_START_BY_MS                     ( 10 * MS_PER_SECOND )                               ///< Delay start of FMP check during dialysate deliver state by this amount of time (in ms).
 #define CONCENTRATE_TEST_COND_COLLECTION_DELAY_MS       ( 5 * MS_PER_SECOND )                                ///< Concentrate test conductivity data collection delay in milliseconds.
 
-#define MAX_RO_REJECTION_RATIO_ALLOW                    0.10F                                                ///< Maximum RO rejection ratio.
 #define MAX_CPO_CONDUCTIVITY_ALLOW                      100.0F                                               ///< Maximum CPo sensor conductivity value.
 #define MIN_FILL_TARGET_TO_CHECK_RO_AND_CPO_ML          550                                                  ///< Minimum fill target to check the RO and CPo alarms in milliliters.
 
@@ -171,6 +170,8 @@
 // NOTE: This variable should be initialized here because the init function is called every time and then it cannot be initialized there. This variable is
 // set via Dialin for calibration check purposes only
 static DIALIN_FILL_FOR_CAL_CHECK_T dialinFillForCalCheck = DIALIN_FILL_FOR_CAL_NONE;                         ///< Dialin fill for calibration check.
+// NOTE: this variable should be initialized here because the init function is called every time and then this variable is set to 0.0.
+static F32 roRejectionRatioFromHD = 0.0F;                                                                    ///< RO rejection ratio from HD.
 static OVERRIDE_F32_T usedAcidVolumeML = { 0.0, 0.0, 0.0, 0.0 };                                             ///< The integrated acid concentration volume has been used in mL.
 static OVERRIDE_F32_T usedBicarbVolumeML = { 0.0, 0.0, 0.0, 0.0 };                                           ///< The integrated bicarb concentration volume has been used in mL.
 static OVERRIDE_U32_T fillModeDataPublishInterval = { FILL_MODE_DATA_PUB_INTERVAL,
@@ -608,6 +609,20 @@
 
 /*********************************************************************//**
  * @brief
+ * The setRORejectionRatio function sets the RO rejection ratio that has
+ * been received from the HD institutional record.
+ * @details Inputs: none
+ * @details Outputs: roRejectionRatioFromHD
+ * @param RO rejection ratio
+ * @return none
+ *************************************************************************/
+void setRORejectionRatio( F32 roRejectionRatio )
+{
+    roRejectionRatioFromHD = roRejectionRatio;
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleTestInletWaterState function tests for inlet water quality
  * and if this is the first fill of a treatment, prime the acid and bicarb
  * lines before jumping to dialysate production state.
@@ -625,6 +640,7 @@
         // to dialysate production directly
         if ( TRUE == isThisTheFirstFill() )
         {
+            sendRORejectionRatioRequestToHD();
             result = DG_FILL_MODE_STATE_PRIME_CONCENTRATE_LINES;
 
             if ( TRUE == getTestConfigStatus( TEST_CONFIG_EXPEDITE_PRE_TREATMENT ) )
@@ -968,10 +984,10 @@
                 // Fault alarm per PRS 483
                 SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_OUTLET_PRIMARY_CONDUCTIVITY_OUT_OF_RANGE, avgCPo, MAX_CPO_CONDUCTIVITY_ALLOW );
             }
-            if ( ( avgRR > MAX_RO_REJECTION_RATIO_ALLOW ) && ( isROOnlyModeEnabled() != TRUE ) )
+            if ( ( avgRR > roRejectionRatioFromHD ) && ( isROOnlyModeEnabled() != TRUE ) )
             {
                 // Fault alarm per PRS 483
-                SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_RO_REJECTION_RATIO_OUT_OF_RANGE, avgRR, MAX_RO_REJECTION_RATIO_ALLOW );
+                SET_ALARM_WITH_2_F32_DATA( ALARM_ID_DG_RO_REJECTION_RATIO_OUT_OF_RANGE, avgRR, roRejectionRatioFromHD );
             }
         }
 
Index: firmware/App/Modes/ModeFill.h
===================================================================
diff -u -r721bd715bef050760e5c0f79044d1cba642c8354 -r30cbd9ff622e635f16df3801aabeb15dfaf5fff5
--- firmware/App/Modes/ModeFill.h	(.../ModeFill.h)	(revision 721bd715bef050760e5c0f79044d1cba642c8354)
+++ firmware/App/Modes/ModeFill.h	(.../ModeFill.h)	(revision 30cbd9ff622e635f16df3801aabeb15dfaf5fff5)
@@ -79,6 +79,8 @@
 
 void setAcidAndBicarbType( U32 acid, U32 bicarb );
 
+void setRORejectionRatio( F32 roRejectionRatio );
+
 BOOL testSetUsedAcidVolumeMLOverride( F32 value );
 BOOL testResetUsedAcidVolumeMLOverride( void );
 
Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r721bd715bef050760e5c0f79044d1cba642c8354 -r30cbd9ff622e635f16df3801aabeb15dfaf5fff5
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 721bd715bef050760e5c0f79044d1cba642c8354)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 30cbd9ff622e635f16df3801aabeb15dfaf5fff5)
@@ -977,6 +977,10 @@
             handleSendDGServiceRecordToHD( message );
             break;
 
+        case MSG_ID_HD_RO_REJ_RATIO_FROM_HD_INSTIT_RECORD_TO_DG_RESPONSE:
+            handleRORejectionResponseFromHDInstitRecord( message );
+            break;
+
         // NOTE: This case must be last
         case MSG_ID_DG_TESTER_LOGIN_REQUEST:
             handleTesterLogInRequest( message );
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r8a89e041755b26fad2530e1b8ad2cfeed1937b0a -r30cbd9ff622e635f16df3801aabeb15dfaf5fff5
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 8a89e041755b26fad2530e1b8ad2cfeed1937b0a)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 30cbd9ff622e635f16df3801aabeb15dfaf5fff5)
@@ -1987,7 +1987,53 @@
     sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_DG_2_HD, status );
 }
 
+/*********************************************************************//**
+ * @brief
+ * The sendRORejectionRatioRequestToHD function handles sending the RO
+ * rejection ratio request to HD
+ * @details Inputs: none
+ * @details Outputs: none
+ * @return none
+ *************************************************************************/
+void sendRORejectionRatioRequestToHD( void )
+{
+    MESSAGE_T msg;
 
+    // Create a message record
+    blankMessage( &msg );
+    msg.hdr.msgID      = MSG_ID_DG_RO_REJ_RATIO_FROM_HD_INSTIT_RECORD_REQUEST;
+    msg.hdr.payloadLen = 0;
+
+    // Serialize the message (w/ sync, CRC, and appropriate CAN padding) and add serialized message data to appropriate comm buffer
+    serializeMessage( msg, COMM_BUFFER_OUT_CAN_DG_2_HD, ACK_REQUIRED );
+}
+
+/*********************************************************************//**
+ * @brief
+ * The handleRORejectionResponseFromHDInstitRecord function handles receiving
+ * RO rejection ratio response from HD institutional record
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none
+ *************************************************************************/
+void handleRORejectionResponseFromHDInstitRecord( MESSAGE_T* message )
+{
+    BOOL status = FALSE;
+
+    if ( message->hdr.payloadLen == sizeof(F32) )
+    {
+        F32 roRejectionRatio;
+
+        memcpy( &roRejectionRatio, message->payload, sizeof(F32) );
+
+
+        status = TRUE;
+    }
+
+    sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_DG_2_HD, status );
+}
+
 // ***********************************************************************
 // **************** Message Handling Helper Functions ********************
 // ***********************************************************************
Index: firmware/App/Services/SystemCommMessages.h
===================================================================
diff -u -r721bd715bef050760e5c0f79044d1cba642c8354 -r30cbd9ff622e635f16df3801aabeb15dfaf5fff5
--- firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 721bd715bef050760e5c0f79044d1cba642c8354)
+++ firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 30cbd9ff622e635f16df3801aabeb15dfaf5fff5)
@@ -201,6 +201,12 @@
 // MSG_ID_DG_START_STOP_NOCTURNAL_HEAT_DISINFECT
 void handleStartStopDGPassiveCoolHeatDisifnect( MESSAGE_T* message );
 
+// MSG_ID_DG_RO_REJ_RATIO_FROM_HD_INSTIT_RECORD_REQUEST
+void sendRORejectionRatioRequestToHD( void );
+
+// MSG_ID_HD_RO_REJ_RATIO_FROM_HD_INSTIT_RECORD_TO_DG_RESPONSE
+void handleRORejectionResponseFromHDInstitRecord( MESSAGE_T* message );
+
 // *********** public test support message functions **********
 
 // MSG_TESTER_LOG_IN