Add heart_beat callback. Cleanup tabulations.

coupler/opc-ua-server/server.c

@@ -37,6 +37,11 @@
 // global Id of coupler
 static int COUPLER_ID = 0;
 
+// global HEART BEATs of coupler
+static int HEART_BEATS = 0;
+
+// the heart beat interval
+static int HEART_BEAT_INTERVAL = 250;
 // The default port of OPC-UA server
 const int DEFAULT_OPC_UA_PORT = 4840;
 const int DEFAULT_MODE = 0;
@@ -122,6 +127,14 @@ static void stopHandler(int sign)
     running = false;
 }
 
+void callbackTicHeartBeat()
+{
+    /* Increase periodically heart beats of the server */ 
+    HEART_BEATS += 1;
+    UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND, "heart_beat %d", HEART_BEATS);
+    // XXX: set OPC ua's heat_beat value
+}
+
 int main(int argc, char **argv)
 {
     int i;
@@ -180,7 +193,7 @@ int main(int argc, char **argv)
     UA_ServerConfig *config = UA_Server_getConfig(server);
     config->verifyRequestTimestamp = UA_RULEHANDLING_ACCEPT;
 
-    // add variables representing physical relarys / inputs, etc
+    // add variables representing physical relaray / inputs, etc
     addVariable(server);
     addValueCallbackToCurrentTimeVariable(server);
 
@@ -229,8 +242,13 @@ int main(int argc, char **argv)
     #endif
 
     // enable keep-alive
-    UA_Int32  defaultInt32 = 0;
-    UA_Int32  couplerID = COUPLER_ID;
+
+    // add a callback which will increment heart beat tics
+    UA_UInt64 callbackId = 1;
+    UA_Server_addRepeatedCallback(server, callbackTicHeartBeat, NULL, HEART_BEAT_INTERVAL, &callbackId);
+
+    UA_Int32  defaultInt32 = 0; //XXX: use unsigned int
+    UA_Int32  couplerID = COUPLER_ID; //XXX: use unsigned int
     const PublishedVariable publishedVariableArray[] = {
         // representing time in millis since start of process
         {