Move to a dedicated file.

coupler/opc-ua-server/keep_alive.h

 /*
 Keep alive implementation for couplers based on OPC UA's pub/sub mechanism
 */
+
+// global HEART BEATs of coupler$
+static unsigned int HEART_BEATS = 0;
+
+// the heart beat interval$
+static int HEART_BEAT_INTERVAL = 250;
+
 // both publisher and subscriber should use same publisher id
 const int PUBLISHER_ID = 2234;
 
@@ -137,3 +144,60 @@ static void addPubSubDataSetField(UA_Server *server, PublishedVariable varDetail
     UA_Server_addDataSetField(server, publishedDataSetIdent,
                               &dataSetFieldConfig, &dataSetFieldIdent);
 }
+
+
+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);
+
+    // set OPC UA's heat_beat node value
+    UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "heart_beat");
+    UA_UInt32 myInteger = HEART_BEATS;
+    UA_Variant myVar;
+    UA_Variant_init(&myVar);
+    UA_Variant_setScalar(&myVar, &myInteger, &UA_TYPES[UA_TYPES_UINT32]);
+    UA_Server_writeValue(server, myIntegerNodeId, myVar);
+}
+
+
+static void enablePublishHeartBeat(UA_Server *erver, UA_ServerConfig *config){
+    int i;
+    // add a callback which will increment heart beat tics
+    UA_UInt64 callbackId = 1;
+    UA_Server_addRepeatedCallback(server, callbackTicHeartBeat, NULL, HEART_BEAT_INTERVAL, &callbackId);
+
+    UA_UInt32  defaultUInt32 = 0;
+    UA_UInt32  couplerID = COUPLER_ID;
+    const PublishedVariable publishedVariableArray[] = {
+        // representing time in millis since start of process
+        {
+            .name = "heart_beat",
+            .description = "Heart beat",
+            .pdefaultValue = &defaultUInt32,
+            .type = UA_TYPES_UINT32
+        },
+        // representing the ID of the coupler
+        {
+            .name = "id",
+            .description = "ID",
+            .pdefaultValue = &couplerID,
+            .type = UA_TYPES_UINT32
+        }
+    };
+
+    UA_String transportProfile =
+        UA_STRING("http://opcfoundation.org/UA-Profile/Transport/pubsub-udp-uadp");
+    UA_NetworkAddressUrlDataType networkAddressUrl =
+        {UA_STRING_NULL , UA_STRING("opc.udp://224.0.0.22:4840/")};
+    UA_ServerConfig_addPubSubTransportLayer(config, UA_PubSubTransportLayerUDPMP());
+    addPubSubConnection(server, &transportProfile, &networkAddressUrl);
+    addPublishedDataSet(server);
+    for(i = 0; i < countof(publishedVariableArray); i++) {
+        addPubSubVariable(server, publishedVariableArray[i]);
+        addPubSubDataSetField(server, publishedVariableArray[i]);
+    }
+    addWriterGroup(server);
+    addDataSetWriter(server);
+}

coupler/opc-ua-server/server.c

@@ -25,7 +25,6 @@
 #include "common.h"
 #include "mod_io_i2c.h"
 #include "mod_io_opc_ua.h"
-#include "keep_alive.h"
 #include <time.h>
 #include <open62541/plugin/log_stdout.h>
 #include <open62541/server.h>
@@ -37,15 +36,11 @@
 // global Id of coupler
 static int COUPLER_ID = 0;
 
-// global HEART BEATs of coupler
-static unsigned int HEART_BEATS = 0;
-
-// the heart beat interval
-static int HEART_BEAT_INTERVAL = 250;
-
 // global server
 UA_Server *server;
 
+#include "keep_alive.h"
+
 // The default port of OPC-UA server
 const int DEFAULT_OPC_UA_PORT = 4840;
 const int DEFAULT_MODE = 0;
@@ -131,20 +126,6 @@ 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);
-
-    // set OPC UA's heat_beat node value
-    UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "heart_beat");
-    UA_UInt32 myInteger = HEART_BEATS;
-    UA_Variant myVar;
-    UA_Variant_init(&myVar);
-    UA_Variant_setScalar(&myVar, &myInteger, &UA_TYPES[UA_TYPES_UINT32]);
-    UA_Server_writeValue(server, myIntegerNodeId, myVar);
-}
 
 int main(int argc, char **argv)
 {
@@ -254,43 +235,7 @@ int main(int argc, char **argv)
     #endif
 
     // enable keep-alive
-
-    // add a callback which will increment heart beat tics
-    UA_UInt64 callbackId = 1;
-    UA_Server_addRepeatedCallback(server, callbackTicHeartBeat, NULL, HEART_BEAT_INTERVAL, &callbackId);
-
-    UA_UInt32  defaultUInt32 = 0;
-    UA_UInt32  couplerID = COUPLER_ID;
-    const PublishedVariable publishedVariableArray[] = {
-        // representing time in millis since start of process
-        {
-            .name = "heart_beat",
-            .description = "Heart beat",
-            .pdefaultValue = &defaultUInt32,
-            .type = UA_TYPES_UINT32
-        },
-        // representing the ID of the coupler
-        {
-            .name = "id",
-            .description = "ID",
-            .pdefaultValue = &couplerID,
-            .type = UA_TYPES_UINT32
-        }
-    };
-
-    UA_String transportProfile =
-        UA_STRING("http://opcfoundation.org/UA-Profile/Transport/pubsub-udp-uadp");
-    UA_NetworkAddressUrlDataType networkAddressUrl =
-        {UA_STRING_NULL , UA_STRING("opc.udp://224.0.0.22:4840/")};
-    UA_ServerConfig_addPubSubTransportLayer(config, UA_PubSubTransportLayerUDPMP());
-    addPubSubConnection(server, &transportProfile, &networkAddressUrl);
-    addPublishedDataSet(server);
-    for(i = 0; i < countof(publishedVariableArray); i++) {
-        addPubSubVariable(server, publishedVariableArray[i]);
-        addPubSubDataSetField(server, publishedVariableArray[i]);
-    }
-    addWriterGroup(server);
-    addDataSetWriter(server);
+    enablePublishHeartBeat(server, config);
 
     // run server
     UA_StatusCode retval = UA_Server_run(server, &running);