diff --git a/lib/config/GWConfig.cpp b/lib/config/GWConfig.cpp
index c6c8532..d8da398 100644
--- a/lib/config/GWConfig.cpp
+++ b/lib/config/GWConfig.cpp
@@ -114,6 +114,16 @@ int GwConfigHandler::getInt(const String name,int defaultv) const{
     if (!i) return defaultv;
     return i->asInt();
 }
+void GwConfigHandler::stopChanges(){
+    allowChanges=false;
+}
+bool GwConfigHandler::setValue(String name,String value){
+    if (! allowChanges) return false;
+    GwConfigInterface *i=getConfigItem(name,false);
+    if (!i) return false;
+    i->value=value;
+    return true;
+}
 
 void GwNmeaFilter::handleToken(String token, int index){
     switch(index){
diff --git a/lib/config/GWConfig.h b/lib/config/GWConfig.h
index 3de56b0..1319f48 100644
--- a/lib/config/GWConfig.h
+++ b/lib/config/GWConfig.h
@@ -14,11 +14,13 @@ class GwConfigHandler: public GwConfigDefinitions{
         GwLog *logger;
         typedef std::map<String,String> StringMap;
         StringMap changedValues;
+        boolean allowChanges=true;
     public:
         public:
         GwConfigHandler(GwLog *logger);
         bool loadConfig();
         bool saveConfig();
+        void stopChanges();
         bool updateValue(String name, String value);
         bool reset(bool save);
         String toString() const;
@@ -27,6 +29,12 @@ class GwConfigHandler: public GwConfigDefinitions{
         bool getBool(const String name,bool defaultv=false) const ;
         int getInt(const String name,int defaultv=0) const;
         GwConfigInterface * getConfigItem(const String name, bool dummy=false) const;
+        /**
+         * change the value of a config item
+         * will become a noop after stopChanges has been called 
+         * !use with care! no checks of the value
+         */
+        bool setValue(String name, String value);
     private:
 };
 #endif
\ No newline at end of file
diff --git a/lib/exampletask/GwExampleTask.cpp b/lib/exampletask/GwExampleTask.cpp
index 18c4a77..88d9cc0 100644
--- a/lib/exampletask/GwExampleTask.cpp
+++ b/lib/exampletask/GwExampleTask.cpp
@@ -10,6 +10,13 @@
  */
 void exampleInit(GwApi *api){
     api->getLogger()->logDebug(GwLog::LOG,"example init running");
+    //this example is a more or less useless example how you could set some
+    //config value to a fixed value
+    //you can only set config values within the init function
+    //you could also compute this value from some own configuration
+    //for this example it would make a lot of sense to declare a capability
+    //to hide this config item from the UI - see header file 
+    api->getConfig()->setValue(api->getConfig()->minXdrInterval,"50"); 
 }
 #define INVALID_COORD -99999
 class GetBoatDataRequest: public GwMessage{
@@ -84,6 +91,7 @@ void exampleTask(GwApi *api){
     bool hasPosition=false;
     bool hasPosition2=false;
     LOG_DEBUG(GwLog::DEBUG,"example switch ist %s",exampleSwitch?"true":"false");
+    LOG_DEBUG(GwLog::DEBUG,"minXdrInterval=%d",api->getConfig()->getInt(api->getConfig()->minXdrInterval));
     GwApi::BoatValue *longitude=new GwApi::BoatValue(F("Longitude"));
     GwApi::BoatValue *latitude=new GwApi::BoatValue(F("Latitude"));
     GwApi::BoatValue *testValue=new GwApi::BoatValue(boatItemName);
diff --git a/lib/exampletask/GwExampleTask.h b/lib/exampletask/GwExampleTask.h
index 4fa5a90..b759c93 100644
--- a/lib/exampletask/GwExampleTask.h
+++ b/lib/exampletask/GwExampleTask.h
@@ -43,4 +43,7 @@ DECLARE_INITFUNCTION(exampleInit);
 //elements when this capability is set correctly
 DECLARE_CAPABILITY(testboard,true);
 DECLARE_CAPABILITY(testboard2,true);
+//hide some config value
+//just set HIDE + the name of the config item to true
+DECLARE_CAPABILITY(HIDEminXdrInterval,true);
 #endif
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 0bbe859..3d9175b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -599,6 +599,10 @@ void setup() {
     logger.prefix="FALLBACK:";
 #endif
   userCodeHandler.startInitTasks(MIN_USER_TASK);
+  config.stopChanges();
+  //maybe the user code changed the level
+  level=config.getInt(config.logLevel,LOGLEVEL);
+  logger.setLevel(level);
   gwWifi.setup();
   MDNS.begin(config.getConfigItem(config.systemName)->asCString());
   channels.begin(fallbackSerial);
@@ -682,7 +686,7 @@ void setup() {
   NMEA2000.SetProductInformation("1", // Manufacturer's Model serial code
                                  100, // Manufacturer's product code
                                  systemName->asCString(),  // Manufacturer's Model ID
-                                 VERSION,  // Manufacturer's Software version code
+                                 FIRMWARE_TYPE,  // Manufacturer's Software version code
                                  VERSION, // Manufacturer's Model version,
                                  N2K_LOAD_LEVEL,
                                  0xffff, //Version
diff --git a/web/index.js b/web/index.js
index 0724ae8..7990241 100644
--- a/web/index.js
+++ b/web/index.js
@@ -953,17 +953,23 @@ function createConfigDefinitions(parent, capabilities, defs,includeXdr) {
             category = item.category;
         }
         let showItem=true;
-        if (item.capabilities !== undefined) {
-            for (let capability in item.capabilities) {
-                let values = item.capabilities[capability];
-                let found = false;
-                if (! (values instanceof Array)) values=[values];
-                values.forEach(function (v) {
+        let itemCapabilities=item.capabilities||{};
+        itemCapabilities['HIDE'+item.name]=null;
+        for (let capability in itemCapabilities) {
+            let values = itemCapabilities[capability];
+            let found = false;
+            if (! (values instanceof Array)) values=[values];
+            values.forEach(function (v) {
+                if ( v === null){
+                    if (capabilities[capability] === undefined) found=true;
+                }
+                else{
                     if (capabilities[capability] == v) found = true;
-                });
-                if (!found) showItem=false;
-            }
+                }
+            });
+            if (!found) showItem=false;
         }
+        
         if (showItem) {
             currentCategoryPopulated=true;
             let row = addEl('div', 'row', categoryEl);