Index: firmware/App/Services/DDInterface.c
===================================================================
diff -u -rda59fa4a98dbc11c37677e92a66aa940d251678f -r1e0e209cd649584ea88b450b36558b2de63c60e2
--- firmware/App/Services/DDInterface.c	(.../DDInterface.c)	(revision da59fa4a98dbc11c37677e92a66aa940d251678f)
+++ firmware/App/Services/DDInterface.c	(.../DDInterface.c)	(revision 1e0e209cd649584ea88b450b36558b2de63c60e2)
@@ -114,6 +114,7 @@
     dialysateDeliveryCmdSet.start             = FALSE;
     dialysateDeliveryCmdSet.dialRate          = 0.0F;
     dialysateDeliveryCmdSet.ufRate            = 0.0F;
+    dialysateDeliveryCmdSet.hdfRate           = 0.0F;    
     dialysateDeliveryCmdSet.dialTemp          = 0.0F;
     dialysateDeliveryCmdSet.bypassDialyzer    = TRUE;
     dialysateDeliveryCmdSet.acidConvFactor    = 0.0F;
@@ -381,6 +382,7 @@
  * @details \b Message \b Sent: Start/continue generate dialysate command.
  * @param qd Target dialysate flow rate (Qd).
  * @param quf Target ultrafiltration rate (Quf) (in mL/min).
+ * @param qhdf Hemodiafiltration rate (Qhdf) (in mL/min).
  * @param dialTemp Target dialysate temperature in deg C.
  * @param bypass Flag indicating whether dialyzer should be bypassed.
  * @param acidConvFactor Conversion factor for the acid used.
@@ -389,11 +391,12 @@
  * @param bicarbonate Level of bicarbonate used in mEq/L.
  * @return none
  *************************************************************************/
-void cmdStartGenerateDialysate( F32 qd, F32 quf, F32 dialTemp, BOOL bypass, F32 acidConvFactor, F32 bicarbConvFactor, U32 sodium, U32 bicarbonate )
+void cmdStartGenerateDialysate( F32 qd, F32 quf, F32 qhdf, F32 dialTemp, BOOL bypass, F32 acidConvFactor, F32 bicarbConvFactor, U32 sodium, U32 bicarbonate )
 {
     dialysateDeliveryCmdSet.start            = TRUE;
     dialysateDeliveryCmdSet.dialRate         = qd;
     dialysateDeliveryCmdSet.ufRate           = quf;
+    dialysateDeliveryCmdSet.hdfRate          = qhdf;    
     dialysateDeliveryCmdSet.dialTemp         = dialTemp;
     dialysateDeliveryCmdSet.bypassDialyzer   = bypass;
     dialysateDeliveryCmdSet.acidConvFactor   = acidConvFactor;
@@ -459,6 +462,31 @@
 
 /*********************************************************************//**
  * @brief
+ * The cmdChangeQhdf function sends a generate dialysate command to the DD
+ * with a given new hemodiafiltration rate.
+ * @details \b Inputs: none
+ * @details \b Outputs: dialysateDeliveryCmdSet
+ * @details \b Message \b Sent: Continue generate dialysate command w/ new Quf.
+ * @param qhdf, hemodiafiltration flow rate (in mL/min).
+ * @return none
+ *************************************************************************/
+void cmdChangeQhdf( F32 qhdf )
+{
+    if ( TRUE == dialysateDeliveryCmdSet.start )
+    {
+        dialysateDeliveryCmdSet.hdfRate = qhdf;
+#ifndef TEST_UI_ONLY
+        sendMessage( MSG_ID_DD_GEN_DIALYSATE_REQUEST_DATA, COMM_BUFFER_OUT_CAN_TD_2_DD, (U08*)(&dialysateDeliveryCmdSet), sizeof( DIALYSATE_DELIVERY_REQ_PAYLOAD_T ) );
+#endif
+    }
+    else
+    {
+        // TODO - s/w fault?
+    }
+}
+
+/*********************************************************************//**
+ * @brief
  * The cmdBypassDialyzer function sends a generate dialysate command to the DD
  * with a given flag indicating whether dialyzer should be bypassed.
  * @details \b Inputs: none