Index: firmware/App/Services/TDInterface.c
===================================================================
diff -u -r322747d530c1b8205be257557e53dcfe9caad50a -r724b64673b719eaac10b0c9dd839ad9675274911
--- firmware/App/Services/TDInterface.c	(.../TDInterface.c)	(revision 322747d530c1b8205be257557e53dcfe9caad50a)
+++ firmware/App/Services/TDInterface.c	(.../TDInterface.c)	(revision 724b64673b719eaac10b0c9dd839ad9675274911)
@@ -20,6 +20,7 @@
 #include "MessagePayloads.h"
 #include "ModeGenDialysate.h"
 #include "ModeInitPOST.h"
+#include "ModePreGenDialysate.h"
 #include "ModeStandby.h"
 #include "OperationModes.h"
 #include "PersistentAlarm.h"
@@ -323,6 +324,49 @@
 
 /*********************************************************************//**
  * @brief
+ * The handlePreGenDialysateRequestMsg function handles a pre gen dailysate
+ * delivery request from TD to perform required self test and priming process.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return TRUE if message is sucessfully parsed, FALSE if not.
+ *************************************************************************/
+BOOL handlePreGenDialysateRequestMsg( MESSAGE_T *message )
+{
+    BOOL result = FALSE;
+
+    if ( message->hdr.payloadLen == sizeof( PRE_GEN_DIALYSATE_REQ_PAYLOAD_T ) )
+    {
+        PRE_GEN_DIALYSATE_REQ_PAYLOAD_T startPreGenRequest;
+        DD_OP_MODE_T ddMode = getCurrentOperationMode();
+
+        memcpy( &startPreGenRequest, message->payload, sizeof( PRE_GEN_DIALYSATE_REQ_PAYLOAD_T ) );
+
+        // Process the pre-gen dialysate delivery request message
+        if ( ( DD_MODE_STAN == ddMode ) && ( TRUE == startPreGenRequest.start ) )
+        {
+            // start dialysate generation
+            result = requestDDPreGenStart();
+        }
+        else if ( DD_MODE_PREG == ddMode )
+        {
+            //TODO : handle transition to post treatment after states defined.
+            if ( FALSE == startPreGenRequest.start )
+            {
+                // stop dialysate generation by transitioning to standby mode
+                requestNewOperationMode( DD_MODE_STAN );
+            }
+            result = TRUE;
+        }
+    }
+
+    sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_DD_2_TD, result );
+
+    return result;
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleDialysateDeliveryRequestMsg function handles a dailysate
  * delivery request from TD and updates dialysate flowrate, UF rate,
  * dialysate temperature, dialyzer bypass and concentrate types ( acid
@@ -344,7 +388,7 @@
         memcpy( &startTxRequest, message->payload, sizeof( DIALYSATE_DELIVERY_REQ_PAYLOAD_T ) );
 
         // Process the dialysate delivery request message
-        if ( ( DD_MODE_STAN == ddMode ) && ( TRUE == startTxRequest.start ) )
+        if ( ( DD_MODE_PREG == ddMode ) && ( TRUE == startTxRequest.start ) )
         {
             // Set dialysate flow rate, UF rate and dialysate temperature
             setTDDialysateFlowrate( startTxRequest.dialRate );
@@ -356,12 +400,13 @@
             setTDDialyzerBypass( startTxRequest.bypassDialyzer );
 
             // start dialysate generation
-            result = requestDDStart();
+            result = requestDDGenDialStart();
         }
         else if ( DD_MODE_GEND == ddMode )
         {
             if ( FALSE == startTxRequest.start )
             {
+                //TODO: Transition to post treatment and then standby.
                 // stop dialysate generation by transitioning to standby mode
                 requestNewOperationMode( DD_MODE_STAN );
             }