Index: firmware/App/Controllers/DGInterface.h
===================================================================
diff -u -rb01542f8e4ef5a29e9b08fc0d465478de516bf02 -rf94085c6fbf817a07db7225d6748b5347dfb12d3
--- firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision b01542f8e4ef5a29e9b08fc0d465478de516bf02)
+++ firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision f94085c6fbf817a07db7225d6748b5347dfb12d3)
@@ -106,6 +106,13 @@
     F32 HtrTrimInternal;
 } DG_TEMPERATURES_T;
 
+/// Payload record structure for a drain reservoir command message.
+typedef struct
+{
+    U32  drainToVolumeML;
+    BOOL tareLoadCells;
+} DRAIN_RESERVOIR_CMD_PAYLOAD_T;
+
 // ********** public function prototypes **********
 
 void initDGInterface( void );
@@ -133,7 +140,7 @@
 void cmdStopDG( void );
 void cmdSetDGActiveReservoir( DG_RESERVOIR_ID_T resID );
 void cmdStartDGFill( U32 fillToVolMl );
-void cmdStartDGDrain( U32 drainToVolMl );
+void cmdStartDGDrain( U32 drainToVolMl, BOOL tareLoadCell );
 void cmdStartDGTrimmerHeater( void );
 void cmdStopDGTrimmerHeater( void );
 void cmdDGSampleWater( void );