When a coupler is in a DOWN state it must NOT

increase it heart beats which itself will cause
dependent couplers to detect that a coupler is DOWN.

coupler/keep_alive.h

@@ -39,7 +39,7 @@ char *NETWORK_INTERFACE = "";
 static unsigned int HEART_BEATS = 0;
 
 // handling coupler's state
-static unsigned int CURRENT_STATE;
+static int CURRENT_STATE=-1;
 const int STATE_UP = 1;
 const int STATE_DOWN = 0;
 const int STATE_NO_INITIAL_HEART_BEAT = 2;

coupler/keep_alive_publisher.h

@@ -147,33 +147,35 @@ static void addPubSubDataSetField(UA_Server *server, PublishedVariable varDetail
 
 void callbackTicHeartBeat()
 {
-    /* Increase periodically heart beats of the server */
-    HEART_BEATS += 1;
+    if (CURRENT_STATE != STATE_DOWN) {
+      /* Increase periodically heart beats of the server */
+      HEART_BEATS += 1;
 
-    // set OPC UA's heat_beat node value
-    UA_NodeId myFloatNodeId = UA_NODEID_STRING(1, "heart_beat");
-    
-    // heart_beat format is <ID_of_coupler>.<heart_beats>
-    int len = snprintf(NULL, 0, "%d", HEART_BEATS);
-    char *result1 = malloc(len + 1);
-    snprintf(result1, len + 1, "%d", HEART_BEATS);
-
-    int len1 = snprintf(NULL, 0, "%d", COUPLER_ID);
-    char *result2 = malloc(len1 + 1);
-    snprintf(result2, len1 + 1, "%d", COUPLER_ID);
+      // set OPC UA's heat_beat node value
+      UA_NodeId myFloatNodeId = UA_NODEID_STRING(1, "heart_beat");
+
+      // heart_beat format is <ID_of_coupler>.<heart_beats>
+      int len = snprintf(NULL, 0, "%d", HEART_BEATS);
+      char *result1 = malloc(len + 1);
+      snprintf(result1, len + 1, "%d", HEART_BEATS);
+
+      int len1 = snprintf(NULL, 0, "%d", COUPLER_ID);
+      char *result2 = malloc(len1 + 1);
+      snprintf(result2, len1 + 1, "%d", COUPLER_ID);
     
-    // concat
-    strcat(result2, ".");
-    strcat(result2, result1);
-   
-    char * end_ptr;
-    float final_result = strtof(result2, &end_ptr );
-
-    UA_Float myFloat = final_result;
-    UA_Variant myVar;
-    UA_Variant_init(&myVar);
-    UA_Variant_setScalar(&myVar, &myFloat, &UA_TYPES[UA_TYPES_FLOAT]);
-    UA_Server_writeValue(server, myFloatNodeId, myVar);
+      // concat
+      strcat(result2, ".");
+      strcat(result2, result1);
+
+      char * end_ptr;
+      float final_result = strtof(result2, &end_ptr );
+
+      UA_Float myFloat = final_result;
+      UA_Variant myVar;
+      UA_Variant_init(&myVar);
+      UA_Variant_setScalar(&myVar, &myFloat, &UA_TYPES[UA_TYPES_FLOAT]);
+      UA_Server_writeValue(server, myFloatNodeId, myVar);
+    }
 }
 
 static void enablePublishHeartBeat(UA_Server *server){