Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -r7cf04dc00d1242aba62f3cd4e4bcb19f1e83ebc6 -r94dab74a6432263dc4569e0cf8f9fa0b01bf1917
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 7cf04dc00d1242aba62f3cd4e4bcb19f1e83ebc6)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 94dab74a6432263dc4569e0cf8f9fa0b01bf1917)
@@ -7,13 +7,15 @@
 *
 * @file    DGInterface.c
 *
-* @author  (last)      Darren Cox
-* @date    (last)      10-Mar-2022
+* @author  (last)      Michael Garthwaite
+* @date    (last)      08-Aug-2022
 *
 * @author  (original)  Sean
 * @date    (original)  08-Apr-2020
 *
 ***************************************************************************/
+
+#include <math.h> // To check for NaN
 
 #include "DialInFlow.h"
 #include "Dialysis.h"
@@ -135,6 +137,7 @@
         for ( j = 0; j < SIZE_OF_LARGE_LOAD_CELL_AVG; j++ )
         {
             lgLoadCellReadings[ i ][ j ] = 0.0;
+            lgLoadCellBackupReadings[ i ][ j ] = 0.0;
         }
     }
 
@@ -481,6 +484,12 @@
  *************************************************************************/
 void setDialysateFlowData( F32 flowRate )
 {
+    // Check if the sent value by DG is a NaN
+    if ( isnan( flowRate ) )
+    {
+        flowRate = 0.0;
+    }
+
     dgDialysateFlowRateMlMin = flowRate;
     dgDialysateFlowDataFreshFlag = TRUE;
 }
@@ -519,7 +528,7 @@
         lgLoadCellReadingsTotal[ res ] += wt;
         lgFilteredReservoirWeightInGrams[ res ] = lgLoadCellReadingsTotal[ res ] / (F32)SIZE_OF_LARGE_LOAD_CELL_AVG;
 
-        wt = ( res == DG_RESERVOIR_1 ? res1Primary : res2Primary );
+        wt = ( res == DG_RESERVOIR_1 ? res1Backup : res2Backup );
         lgLoadCellBackupReadingsTotal[ res ] -= lgLoadCellBackupReadings[ res ][ lgLoadCellReadingsIdx ];
         lgLoadCellBackupReadings[ res ][ lgLoadCellReadingsIdx ] = wt;
         lgLoadCellBackupReadingsTotal[ res ] += wt;
@@ -863,6 +872,19 @@
 
 /*********************************************************************//**
  * @brief
+ * The cmdSetDGToServiceMode function sends a request to DG to transition
+ * to service mode.
+ * @details Inputs: none
+ * @details Outputs: none
+ * @return none
+ *************************************************************************/
+void cmdSetDGToServiceMode( void )
+{
+    sendDGServiceModeRequest();
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleDGCommandResponse function processes the latest DG command response.
  * @details Inputs: none
  * @details Outputs: process command response from DG