Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -re23087e0c17f6ea81d60641fdb52121a8dd5a099 -r27f3db92495948d4c1192421c1b0c20338c4a034
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision e23087e0c17f6ea81d60641fdb52121a8dd5a099)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 27f3db92495948d4c1192421c1b0c20338c4a034)
@@ -109,7 +109,7 @@
 static F32 resUseVolumeMl = 0.0;                                ///< Accumulated volume used from active reservoir.
 
 // DG command response
-static DG_CMD_RESPONSE_T dgCmdResp;                             ///< Used to keep the latest DG command response.
+static DG_CMD_RESPONSE_T dgCmdResp[ NUM_OF_DG_COMMANDS ];       ///< Keep the latest DG command response for each command.
 
 // ********** private function prototypes **********
 
@@ -157,9 +157,13 @@
         }
     }
 
-    dgCmdResp.commandID = DG_CMD_NONE;
-    dgCmdResp.rejected  = TRUE;
-    dgCmdResp.rejectCode = DG_CMD_REQUEST_REJECT_REASON_NONE;
+    // initialize DG command response
+    for ( i = 0; i < NUM_OF_DG_COMMANDS; i++ )
+    {
+        dgCmdResp[ i ].commandID  = DG_CMD_NONE;
+        dgCmdResp[ i ].rejected   = TRUE;
+        dgCmdResp[ i ].rejectCode = DG_CMD_REQUEST_REJECT_REASON_NONE;
+    }
 
     smLoadCellReadingsIdx = 0;
     smLoadCellReadingsTotal[ DG_RESERVOIR_1 ] = 0.0;
@@ -309,11 +313,10 @@
             if ( ( DG_MODE_CIRC == getDGOpMode() ) && ( DG_RECIRCULATE_MODE_STATE_RECIRC_WATER == getDGSubMode() ) &&
                   ( resUseVolumeMl >= (F32)dgReservoirFillVolumeTargetSet ) )
             {
-                DG_RESERVOIR_ID_T activeRes = dgActiveReservoirSet;
-                DG_RESERVOIR_ID_T inactiveRes = ( activeRes == DG_RESERVOIR_1 ? DG_RESERVOIR_2 : DG_RESERVOIR_1 );
+                DG_RESERVOIR_ID_T inactiveRes = getDGInactiveReservoir();
 
                 // Signal dialysis sub-mode to capture baseline volume for next reservoir.
-                setStartReservoirVolume();
+                setStartReservoirVolume( inactiveRes );
                 // Command DG to switch reservoirs
                 cmdSetDGActiveReservoir( inactiveRes );
                 // Signal dialysis sub-mode to switch reservoirs
@@ -760,7 +763,7 @@
 void cmdStartDGTrimmerHeater( void )
 {
     dgTrimmerHeaterOn = TRUE;
-    dgCmdResp.commandID = DG_CMD_NONE;
+    dgCmdResp[ DG_CMD_START_TRIMMER_HEATER ].commandID = DG_CMD_NONE;
     sendDGStartStopTrimmerHeaterCommand( START_DG_CMD, dgTrimmerTempSet );
 }
 
@@ -775,7 +778,7 @@
 void cmdStopDGTrimmerHeater( void )
 {
     dgTrimmerHeaterOn = FALSE;
-    dgCmdResp.commandID = DG_CMD_NONE;
+    dgCmdResp[ DG_CMD_STOP_TRIMMER_HEATER ].commandID = DG_CMD_NONE;
     sendDGStartStopTrimmerHeaterCommand( STOP_DG_CMD, 0 );
 }
 
@@ -793,14 +796,36 @@
     if ( resID < NUM_OF_DG_RESERVOIRS )
     {
         dgActiveReservoirSet = resID;
-        dgCmdResp.commandID = DG_CMD_NONE;
+        dgCmdResp[ DG_CMD_SWITCH_RESERVOIR ].commandID = DG_CMD_NONE;
         sendDGSwitchReservoirCommand( (U32)resID );
     }
     else
     {
-        // TODO - s/w fault
+        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_HD_INVALID_RESERVOIR_ID, (U32)resID );
     }
 }
+
+/*********************************************************************//**
+ * @brief
+ * The cmdChangeDGValveSetting function sends a change valve setting command
+ * message to the DG.
+ * @details Inputs: none
+ * @details Outputs: change valve setting command sent to DG.
+ * @param valveSettingID ID of valve setting to change to
+ * @return none
+ *************************************************************************/
+void cmdChangeDGValveSetting( DG_VALVE_SETTING_ID_T valveSettingID )
+{
+    if ( valveSettingID < NUM_OF_DG_VALVE_SETTTINGS )
+    {
+        dgCmdResp[ DG_CMD_VALVE_SETTING ].commandID = DG_CMD_NONE;
+        sendDGChangeValveSettingCommand( (U32)valveSettingID );
+    }
+    else
+    {
+        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_HD_INVALID_VALVE_SETTING_ID, (U32)valveSettingID );
+    }
+}
 
 /*********************************************************************//**
  * @brief
@@ -812,7 +837,7 @@
  *************************************************************************/
 void cmdStartDGFill( U32 fillToVolMl )
 {
-    dgCmdResp.commandID = DG_CMD_NONE;
+    dgCmdResp[ DG_CMD_START_FILL ].commandID = DG_CMD_NONE;
     dgReservoirFillVolumeTargetSet = fillToVolMl;
     sendDGFillCommand( fillToVolMl );
 }
@@ -830,7 +855,7 @@
 {
     DRAIN_RESERVOIR_CMD_PAYLOAD_T payload;
 
-    dgCmdResp.commandID = DG_CMD_NONE;
+    dgCmdResp[ DG_CMD_START_DRAIN ].commandID = DG_CMD_NONE;
     payload.drainToVolumeML = drainToVolMl;
     payload.tareLoadCells = tareLoadCell;
     dgReservoirDrainVolumeTargetSet = drainToVolMl;
@@ -855,16 +880,26 @@
  * The handleDGCommandResponse function processes the latest DG command response.
  * @details Inputs: none
  * @details Outputs: process command response from DG
- * @param cmdRespPtr pointer to DG command response data record
+ * @param dgCmdRespPtr pointer to DG command response data record
  * @return none
  *************************************************************************/
-void handleDGCommandResponse( U08 *cmdRespPtr )
+void handleDGCommandResponse( DG_CMD_RESPONSE_T *dgCmdRespPtr )
 {
-    memcpy( &dgCmdResp, cmdRespPtr, sizeof( DG_CMD_RESPONSE_T ) );
+    if ( dgCmdRespPtr->commandID < NUM_OF_DG_COMMANDS )
+    {
+        if ( DG_CMD_NONE != dgCmdRespPtr->commandID )
+        {
+            memcpy( &dgCmdResp[ dgCmdRespPtr->commandID ], dgCmdRespPtr, sizeof( DG_CMD_RESPONSE_T ) );
+        }
+    }
+    else
+    {
+        SET_ALARM_WITH_2_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_HD_INVALID_COMMAND_RESPONSE_ID, dgCmdRespPtr->commandID );
+    }
 
-    if ( TRUE == dgCmdResp.rejected )
+    if ( TRUE == dgCmdRespPtr->rejected )
     {
-        switch ( dgCmdResp.rejectCode )
+        switch ( dgCmdRespPtr->rejectCode )
         {
             case DG_CMD_REQUEST_REJECT_REASON_INVALID_PARAMETER:
                 activateAlarmNoData( ALARM_ID_DG_COMMAND_INVALID_PARAMETER_FAULT );
@@ -885,12 +920,22 @@
  * The getDGCommandResponse function gets the latest command response from DG.
  * @details Inputs: dgCmdResp
  * @details Outputs: none
+ * @param commandID id of specific interested command response
  * @param cmdRespPtr pointer to data record to copy DG command response to
- * @return none
+ * @return TRUE if a specific command response has been received, otherwise FALSE
  *************************************************************************/
-void getDGCommandResponse( DG_CMD_RESPONSE_T *cmdRespPtr )
+BOOL getDGCommandResponse( U32 commandID, DG_CMD_RESPONSE_T *cmdRespPtr )
 {
-    memcpy( &cmdRespPtr, &dgCmdResp, sizeof( DG_CMD_RESPONSE_T ) );
+    BOOL hasCommandResp = FALSE;
+
+    if ( commandID == dgCmdResp[ commandID ].commandID )
+    {
+        hasCommandResp = TRUE;
+        memcpy( cmdRespPtr, &dgCmdResp[ commandID ], sizeof( DG_CMD_RESPONSE_T ) );
+        dgCmdResp[ commandID ].commandID = DG_CMD_NONE;
+    }
+
+    return hasCommandResp;
 }