Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r3417fd56afc9b21fb4c2d86c75dd33ac31fbd9f1 -r070554b23739bf16ea2bf9528ebabda1ce0ffeb3
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 3417fd56afc9b21fb4c2d86c75dd33ac31fbd9f1)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 070554b23739bf16ea2bf9528ebabda1ce0ffeb3)
@@ -71,6 +71,10 @@
 static g_dmaCTRL pcDMAXmitControlRecord;
 static g_dmaCTRL pcDMARecvControlRecord;
 
+static BOOL dgIsCommunicating = FALSE;
+static BOOL uiIsCommunicating = FALSE;
+static BOOL uiDidCommunicate = FALSE;
+
 // ********** private function prototypes **********
 
 static void initUARTAndDMA( void );
@@ -103,6 +107,89 @@
 }
 
 /*************************************************************************
+ * @brief checkInFromDG
+ * The checkInFromDG function checks in the DG with the HD - indicating that \n
+ * the DG is communicating.
+ * @details
+ * Inputs : none
+ * Outputs : dgIsCommunicating
+ * @param none
+ * @return none
+ *************************************************************************/
+void checkInFromDG( void )
+{
+    dgIsCommunicating = TRUE;
+}
+
+/*************************************************************************
+ * @brief checkInFromUI
+ * The checkInFromUI function checks in the UI with the HD - indicating that \n
+ * the UI is communicating.
+ * @details
+ * Inputs : none
+ * Outputs : uiIsCommunicating
+ * @param none
+ * @return none
+ *************************************************************************/
+void checkInFromUI( void )
+{
+    uiIsCommunicating = TRUE;
+    uiDidCommunicate = TRUE;
+}
+
+/*************************************************************************
+ * @brief isDGCommunicating
+ * The isDGCommunicating function determines whether the DG is communicating \n
+ * with the HD.
+ * @details
+ * Inputs : dgIsCommunicating
+ * Outputs : none
+ * @param none
+ * @return TRUE if DG has checked in since last call, FALSE if not
+ *************************************************************************/
+BOOL isDGCommunicating( void )
+{
+    BOOL result = dgIsCommunicating;
+
+    dgIsCommunicating = FALSE;
+
+    return result;
+}
+
+/*************************************************************************
+ * @brief isUICommunicating
+ * The isUICommunicating function determines whether the UI is communicating \n
+ * with the HD.
+ * @details
+ * Inputs : uiIsCommunicating
+ * Outputs : none
+ * @param none
+ * @return TRUE if UI has checked in since last call, FALSE if not
+ *************************************************************************/
+BOOL isUICommunicating( void )
+{
+    BOOL result = uiIsCommunicating;
+
+    uiIsCommunicating = FALSE;
+
+    return result;
+}
+
+/*************************************************************************
+ * @brief uiCommunicated
+ * The uiCommunicated function determines whether the UI has communicated.
+ * @details
+ * Inputs : uiDidCommunicate
+ * Outputs : none
+ * @param none
+ * @return TRUE if UI has communicated since power up, FALSE if not
+ *************************************************************************/
+BOOL uiCommunicated( void )
+{
+    return uiDidCommunicate;
+}
+
+/*************************************************************************
  * @brief execSystemCommRx
  * The execSystemCommRx function manages received data from other sub-systems.
  * @details
@@ -635,8 +722,16 @@
 #endif
             break;
 
+        case MSG_ID_DG_CHECK_IN:
+            handleDGCheckIn( message );
+            break;
 
+        case MSG_ID_UI_CHECK_IN:
+            handleUICheckIn( message );
+            break;
 
+
+
         case MSG_ID_TESTER_LOGIN_REQUEST:
             handleTesterLogInRequest( message );
             break;