Index: firmware/App/Modes/ModeStandby.c
===================================================================
diff -u -r79c2105d7ec35f3caeb977f6e2cc1b494853d211 -rdb8ff28e816a37e033e36b76ab5949be78114125
--- firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision 79c2105d7ec35f3caeb977f6e2cc1b494853d211)
+++ firmware/App/Modes/ModeStandby.c	(.../ModeStandby.c)	(revision db8ff28e816a37e033e36b76ab5949be78114125)
@@ -23,6 +23,7 @@
 #include "ModeTxParams.h"
 #include "ModeStandby.h"
 #include "OperationModes.h"
+#include "SystemCommTD.h"
 
 /**
  *  @addtogroup TDStandbyMode
@@ -71,7 +72,7 @@
 
     // Re-initialize when transitioning to standby mode
     initStandbyMode();
-    initDDInterface();
+    resetDDInterface();
     setCurrentSubState( NO_SUB_STATE );
 
     // Set user alarm recovery actions allowed in this mode
@@ -203,7 +204,7 @@
 static TD_STANDBY_STATE_T handleStandbyModeWaitForTreatmentState( void )
 {
     TD_STANDBY_STATE_T state     = STANDBY_WAIT_FOR_TREATMENT_STATE;
-//    DG_OP_MODE_T dgOperationMode = getDDOpMode();
+    DD_OP_MODE_T ddOperationMode = getDDOpMode();
 
 //    switch ( dgOperationMode )
 //    {
@@ -293,6 +294,16 @@
             {
                 rejReason = REQUEST_REJECT_REASON_NOT_ALLOWED_IN_CURRENT_MODE;
             }
+            // Verify DD is communicating with HD
+            else if ( isDDCommunicating() != TRUE )
+            {
+                rejReason = REQUEST_REJECT_REASON_DD_COMM_LOST;
+            }
+            // Verify DD is not busy
+            else if ( ( DD_MODE_STAN != getDDOpMode() ) || ( DD_STANDBY_MODE_STATE_IDLE != getDDSubMode() ) ) // || ( isDDPOSTPassed() != TRUE ) )
+            {
+                rejReason = REQUEST_REJECT_REASON_DD_NOT_IN_STANDBY_IDLE_STATE;
+            }
             else
             {
                 // If request to start treatment not rejected, set flag to initiate treatment workflow