Index: firmware/App/Services/TDInterface.c
===================================================================
diff -u -re01f6c0b94312dec30878967be9ffa3228e8773b -r07340ea19b917f515c85e42c7904c748aa7c7dcf
--- firmware/App/Services/TDInterface.c	(.../TDInterface.c)	(revision e01f6c0b94312dec30878967be9ffa3228e8773b)
+++ firmware/App/Services/TDInterface.c	(.../TDInterface.c)	(revision 07340ea19b917f515c85e42c7904c748aa7c7dcf)
@@ -335,6 +335,7 @@
 BOOL handlePreGenDialysateRequestMsg( MESSAGE_T *message )
 {
     BOOL result = FALSE;
+    REQUEST_REJECT_REASON_CODE_T fpReason = REQUEST_REJECT_REASON_NONE;
 
     if ( message->hdr.payloadLen == sizeof( PRE_GEN_DIALYSATE_REQ_PAYLOAD_T ) )
     {
@@ -347,9 +348,14 @@
         if ( ( DD_MODE_STAN == ddMode ) && ( TRUE == startPreGenRequest.start ) )
         {
             // Start FP Pre-Generate Permeate
-            requestFPGeneratePermeate( RO_PRE_GEN, TRUE );
+            fpReason = signalStartGenPermeate();
             // start pre-gen dialysate
             result = requestDDPreGenStart();
+
+            if ( REQUEST_REJECT_REASON_NONE != fpReason )
+            {
+                result = FALSE;
+            }
             // Update Temperature, Acid/Bicarb type and dialysate rate for pregen process.
             setTDDialysateFlowrate( startPreGenRequest.dialRate );
             setTDTargetDialysateTemperature( startPreGenRequest.dialTemp );
@@ -361,6 +367,13 @@
             {
                 // stop pre generate diaysate delivery
                 result = requestDDPreGenStop();
+                // stop FP Pre-Generate Permeate
+                fpReason = signalStopGenPermeate();
+
+                if ( REQUEST_REJECT_REASON_NONE != fpReason )
+                {
+                    result = FALSE;
+                }
             }
         }
     }
@@ -384,6 +397,7 @@
 BOOL handleDialysateDeliveryRequestMsg( MESSAGE_T *message )
 {
     BOOL result = FALSE;
+    REQUEST_REJECT_REASON_CODE_T fpReason = REQUEST_REJECT_REASON_NONE;
 
     if ( message->hdr.payloadLen == sizeof( DIALYSATE_DELIVERY_REQ_PAYLOAD_T ) )
     {
@@ -413,6 +427,13 @@
             {
                 // stop dialysate generation
                 result = requestDDGenDialyasteStop();
+                // stop FP Pre-Generate Permeate
+                fpReason = signalStopGenPermeate();
+
+                if ( REQUEST_REJECT_REASON_NONE != fpReason )
+                {
+                    result = FALSE;
+                }
             }
             else
             {