Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -r27a68f930508638f2eb6265ebb381c8918cbc37b -r7cf04dc00d1242aba62f3cd4e4bcb19f1e83ebc6
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 27a68f930508638f2eb6265ebb381c8918cbc37b)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 7cf04dc00d1242aba62f3cd4e4bcb19f1e83ebc6)
@@ -69,11 +69,14 @@
 static OVERRIDE_F32_T loadCellWeightInGrams[ NUM_OF_LOAD_CELLS ];
 /// Filtered (32 sample) weight of reservoirs.
 static F32 lgFilteredReservoirWeightInGrams[ NUM_OF_DG_RESERVOIRS ];
+static F32 lgFilteredReservoirBackupWeightInGrams[ NUM_OF_DG_RESERVOIRS ];
 
 // Load cell filtering data
 static F32 lgLoadCellReadings[ NUM_OF_DG_RESERVOIRS ][ SIZE_OF_LARGE_LOAD_CELL_AVG ];  ///< Holds load cell samples for large load cell moving average.
 static U32 lgLoadCellReadingsIdx = 0;                           ///< Index for next sample in large load cell rolling average sample array.
 static F32 lgLoadCellReadingsTotal[ NUM_OF_DG_RESERVOIRS ];     ///< Rolling total - used to calc large load cell moving average.
+static F32 lgLoadCellBackupReadings[ NUM_OF_DG_RESERVOIRS ][ SIZE_OF_LARGE_LOAD_CELL_AVG ];  ///< Holds load cell samples for large load cell moving average.
+static F32 lgLoadCellBackupReadingsTotal[ NUM_OF_DG_RESERVOIRS ];     ///< Rolling total - used to calc large load cell moving average.
 
 // DG Dialysate flow rate
 static F32  dgDialysateFlowRateMlMin = 0.0;                     ///< Latest dialysate flow rate reported by the DG.
@@ -146,6 +149,8 @@
     lgLoadCellReadingsIdx = 0;
     lgLoadCellReadingsTotal[ DG_RESERVOIR_1 ] = 0.0;
     lgLoadCellReadingsTotal[ DG_RESERVOIR_2 ] = 0.0;
+    lgLoadCellBackupReadingsTotal[ DG_RESERVOIR_1 ] = 0.0;
+    lgLoadCellBackupReadingsTotal[ DG_RESERVOIR_2 ] = 0.0;
 
     initPersistentAlarm( ALARM_ID_DIALYSATE_TEMPERATURE_HIGH, DIALYSATE_TEMP_PERSISTENCE_PERIOD, DIALYSATE_TEMP_PERSISTENCE_PERIOD );
     initPersistentAlarm( ALARM_ID_DIALYSATE_TEMPERATURE_LOW, DIALYSATE_TEMP_PERSISTENCE_PERIOD, DIALYSATE_TEMP_PERSISTENCE_PERIOD );
@@ -329,6 +334,27 @@
 
 /*********************************************************************//**
  * @brief
+ * The getReservoirBackupWeightLargeFilter function gets the backup load cell weight
+ * of the given reservoir after large (32 sample) filter applied.
+ * @details Inputs: lgFilteredReservoirWeightInGrams[]
+ * @details Outputs: none
+ * @param resID ID of reservoir to get filtered weight for
+ * @return the current filtered weight of the given reservoir in grams
+ *************************************************************************/
+F32 getReservoirBackupWeightLargeFilter( DG_RESERVOIR_ID_T resID )
+{
+    F32 result = 0.0;
+
+    if ( resID < NUM_OF_DG_RESERVOIRS )
+    {
+        result = lgFilteredReservoirBackupWeightInGrams[ resID ];
+    }
+
+    return result;
+}
+
+/*********************************************************************//**
+ * @brief
  * The getDialysateTemperature function gets the latest dialysate temperature.
  * @details Inputs: dgDialysateTemp
  * @details Outputs: none
@@ -492,6 +518,12 @@
         lgLoadCellReadings[ res ][ lgLoadCellReadingsIdx ] = wt;
         lgLoadCellReadingsTotal[ res ] += wt;
         lgFilteredReservoirWeightInGrams[ res ] = lgLoadCellReadingsTotal[ res ] / (F32)SIZE_OF_LARGE_LOAD_CELL_AVG;
+
+        wt = ( res == DG_RESERVOIR_1 ? res1Primary : res2Primary );
+        lgLoadCellBackupReadingsTotal[ res ] -= lgLoadCellBackupReadings[ res ][ lgLoadCellReadingsIdx ];
+        lgLoadCellBackupReadings[ res ][ lgLoadCellReadingsIdx ] = wt;
+        lgLoadCellBackupReadingsTotal[ res ] += wt;
+        lgFilteredReservoirBackupWeightInGrams[ res ] = lgLoadCellBackupReadingsTotal[ res ] / (F32)SIZE_OF_LARGE_LOAD_CELL_AVG;
     }
     lgLoadCellReadingsIdx = INC_WRAP( lgLoadCellReadingsIdx, 0, SIZE_OF_LARGE_LOAD_CELL_AVG - 1 );