Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -rb32dd9e582f74d0ddc106a0d0b1efa8974c08c4d -r2f2419f67d9d458837893fef5cc1b21870021026
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision b32dd9e582f74d0ddc106a0d0b1efa8974c08c4d)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 2f2419f67d9d458837893fef5cc1b21870021026)
@@ -824,8 +824,22 @@
 {
     dgCmdResp[ DG_CMD_START_FILL ].commandID = DG_CMD_NONE;
     dgReservoirFillVolumeTargetSet = fillToVolMl;
-    sendDGFillCommand( fillToVolMl );
+    sendDGFillCommand( DG_CMD_START, fillToVolMl );
 }
+
+/*********************************************************************//**
+ * @brief
+ * The cmdStopDGFill function sends a fill command with stop parameter message to the DG.
+ * @details Inputs: none
+ * @details Outputs: fill command with stop parameter sent to DG.
+ * @return none
+ *************************************************************************/
+void cmdStopDGFill( void )
+{
+    dgCmdResp[ DG_CMD_STOP_FILL ].commandID = DG_CMD_NONE;
+    dgReservoirFillVolumeTargetSet = 0;
+    sendDGFillCommand( DG_CMD_STOP, 0 );
+}
 
 /*********************************************************************//**
  * @brief
Index: firmware/App/Controllers/DGInterface.h
===================================================================
diff -u -rb32dd9e582f74d0ddc106a0d0b1efa8974c08c4d -r2f2419f67d9d458837893fef5cc1b21870021026
--- firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision b32dd9e582f74d0ddc106a0d0b1efa8974c08c4d)
+++ firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision 2f2419f67d9d458837893fef5cc1b21870021026)
@@ -148,7 +148,8 @@
 void cmdStopDG( void );
 void cmdSetDGActiveReservoir( DG_RESERVOIR_ID_T resID );
 void cmdChangeDGValveSetting( DG_VALVE_SETTING_ID_T valveSettingID );
-void cmdStartDGFill( U32 fillToVolMl );
+void cmdStartDGFill( U32 fillToVolMl );
+void cmdStopDGFill( void );
 void cmdStartDGDrain( U32 drainToVolMl, BOOL tareLoadCell );
 void cmdStartDGTrimmerHeater( void );
 void cmdStopDGTrimmerHeater( void );
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -red962b050e6b9714318a0b9034742efc2ccb9e4f -r2f2419f67d9d458837893fef5cc1b21870021026
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision ed962b050e6b9714318a0b9034742efc2ccb9e4f)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 2f2419f67d9d458837893fef5cc1b21870021026)
@@ -781,11 +781,12 @@
  * The sendDGFillCommand function constructs a DG fill command message
  * and queues the msg for transmit on the appropriate CAN channel.
  * @details Inputs: none
- * @details Outputs: DG fill command msg constructed and queued.
+ * @details Outputs: DG fill command msg constructed and queued.
+ * @param cmd start or stop fill command
  * @param fillToVolumeMl volume (in mL) to fill inactive reservoir to
  * @return TRUE if msg successfully queued for transmit, FALSE if not
  *************************************************************************/
-BOOL sendDGFillCommand( U32 fillToVolumeMl )
+BOOL sendDGFillCommand( U32 cmd, U32 fillToVolumeMl )
 {
     BOOL result;
     MESSAGE_T msg;
@@ -794,10 +795,12 @@
     // Create a message record
     blankMessage( &msg );
     msg.hdr.msgID = MSG_ID_DG_FILL_CMD;
-    msg.hdr.payloadLen = sizeof( U32 );
+    msg.hdr.payloadLen = sizeof( U32 ) + sizeof( U32 );
+
+    memcpy( payloadPtr, &fillToVolumeMl, sizeof( U32 ) );
+    payloadPtr += sizeof( U32 );
+    memcpy( payloadPtr, &cmd, sizeof( U32 ) );
 
-    memcpy( payloadPtr, &fillToVolumeMl, sizeof( U32 ) );
-
     // Serialize the message (w/ sync, CRC, and appropriate CAN padding) and add serialized message data to appropriate comm buffer
     result = serializeMessage( msg, COMM_BUFFER_OUT_CAN_HD_2_DG, ACK_REQUIRED );
 
Index: firmware/App/Services/SystemCommMessages.h
===================================================================
diff -u -red962b050e6b9714318a0b9034742efc2ccb9e4f -r2f2419f67d9d458837893fef5cc1b21870021026
--- firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision ed962b050e6b9714318a0b9034742efc2ccb9e4f)
+++ firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 2f2419f67d9d458837893fef5cc1b21870021026)
@@ -200,7 +200,7 @@
 BOOL sendDGChangeValveSettingCommand( U32 valveSettingCmd );
 
 // MSG_ID_DG_FILL_CMD
-BOOL sendDGFillCommand( U32 fillToVolumeMl );
+BOOL sendDGFillCommand( U32 cmd, U32 fillToVolumeMl );
 
 // MSG_ID_DG_DRAIN_CMD
 BOOL sendDGDrainCommand( DRAIN_RESERVOIR_CMD_PAYLOAD_T *drainCmdPtr );