diff --git a/src/knx/bau_systemB.cpp b/src/knx/bau_systemB.cpp
index b727148..f76e512 100644
--- a/src/knx/bau_systemB.cpp
+++ b/src/knx/bau_systemB.cpp
@@ -164,6 +164,9 @@ void BauSystemB::memoryRoutingTableWriteIndication(Priority priority, HopCountTy
 
     if (_deviceObj.verifyMode())
         memoryRoutingTableReadIndication(priority, hopType, asap, secCtrl, number, memoryAddress, data);
+
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 void BauSystemB::memoryWriteIndication(Priority priority, HopCountType hopType, uint16_t asap, const SecurityControl& secCtrl, uint8_t number,
@@ -173,6 +176,9 @@ void BauSystemB::memoryWriteIndication(Priority priority, HopCountType hopType,
 
     if (_deviceObj.verifyMode())
         memoryReadIndication(priority, hopType, asap, secCtrl, number, memoryAddress, data);
+        
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 void BauSystemB::memoryReadIndication(Priority priority, HopCountType hopType, uint16_t asap, const SecurityControl& secCtrl, uint8_t number,
@@ -193,6 +199,9 @@ void BauSystemB::memoryExtWriteIndication(Priority priority, HopCountType hopTyp
     _memory.writeMemory(memoryAddress, number, data);
 
     applicationLayer().memoryExtWriteResponse(AckRequested, priority, hopType, asap, secCtrl, ReturnCodes::Success, number, memoryAddress, _memory.toAbsolute(memoryAddress));
+
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 void BauSystemB::memoryExtReadIndication(Priority priority, HopCountType hopType, uint16_t asap, const SecurityControl& secCtrl, uint8_t number, uint32_t memoryAddress)
@@ -252,6 +261,9 @@ void BauSystemB::userMemoryWriteIndication(Priority priority, HopCountType hopTy
 
     if (_deviceObj.verifyMode())
         userMemoryReadIndication(priority, hopType, asap, secCtrl, number, memoryAddress);
+        
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 void BauSystemB::propertyDescriptionReadIndication(Priority priority, HopCountType hopType, uint16_t asap, const SecurityControl& secCtrl, uint8_t objectIndex,
@@ -311,6 +323,9 @@ void BauSystemB::propertyValueWriteIndication(Priority priority, HopCountType ho
         obj->writeProperty((PropertyID)propertyId, startIndex, data, numberOfElements);
 
     propertyValueReadIndication(priority, hopType, asap, secCtrl, objectIndex, propertyId, numberOfElements, startIndex);
+    
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 void BauSystemB::propertyValueExtWriteIndication(Priority priority, HopCountType hopType, uint16_t asap, const SecurityControl& secCtrl, ObjectType objectType, uint8_t objectInstance,
@@ -329,6 +344,9 @@ void BauSystemB::propertyValueExtWriteIndication(Priority priority, HopCountType
     {
         applicationLayer().propertyValueExtWriteConResponse(AckRequested, priority, hopType, asap, secCtrl, objectType, objectInstance, propertyId, numberOfElements, startIndex, returnCode);
     }
+    
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 void BauSystemB::propertyValueReadIndication(Priority priority, HopCountType hopType, uint16_t asap, const SecurityControl& secCtrl, uint8_t objectIndex,
@@ -765,6 +783,9 @@ void BauSystemB::propertyValueWrite(ObjectType objectType, uint8_t objectInstanc
         obj->writeProperty((PropertyID)propertyId, startIndex, data, numberOfElements);
     else
         numberOfElements = 0;
+        
+    if(_unloadStartet != 0)
+        _unloadStartet = millis(); // reset unload timer
 }
 
 Memory& BauSystemB::memory()
diff --git a/src/knx/bau_systemB.h b/src/knx/bau_systemB.h
index 576dac7..2574ffc 100644
--- a/src/knx/bau_systemB.h
+++ b/src/knx/bau_systemB.h
@@ -130,4 +130,6 @@ class BauSystemB : protected BusAccessUnit
         BeforeRestartCallback _beforeRestart = 0;
         FunctionPropertyCallback _functionProperty = 0;
         FunctionPropertyCallback _functionPropertyState = 0;
+        
+        unsigned long _unloadStartet = 0;
 };
diff --git a/src/knx/bau_systemB_coupler.cpp b/src/knx/bau_systemB_coupler.cpp
index e71164f..984ef42 100644
--- a/src/knx/bau_systemB_coupler.cpp
+++ b/src/knx/bau_systemB_coupler.cpp
@@ -33,6 +33,17 @@ void BauSystemBCoupler::loop()
 #ifdef USE_DATASECURE
     _appLayer.loop();
 #endif
+
+#ifdef USE_DATASECURE
+    if(_unloadStartet == 0 && _secIfObj.getWasUnloaded())
+    {
+        _unloadStartet = millis();
+    } else if(millis() - _unloadStartet > 5000)
+    {
+        writeMemory();
+        _unloadStartet = 0;
+    }
+#endif
 }
 
 bool BauSystemBCoupler::configured()
diff --git a/src/knx/bau_systemB_device.cpp b/src/knx/bau_systemB_device.cpp
index 872d677..c59bcf4 100644
--- a/src/knx/bau_systemB_device.cpp
+++ b/src/knx/bau_systemB_device.cpp
@@ -49,6 +49,24 @@ void BauSystemBDevice::loop()
 #ifdef USE_DATASECURE
     _appLayer.loop();
 #endif
+
+    if(_unloadStartet == 0)
+    {
+        if(_addrTable.getWasUnloaded()
+            || _assocTable.getWasUnloaded() 
+            || _groupObjTable.getWasUnloaded()
+#ifdef USE_DATASECURE
+            || _secIfObj.getWasUnloaded()
+#endif
+            )
+        {
+            _unloadStartet = millis();
+        } 
+    } else if(millis() - _unloadStartet > 5000)
+    {
+        writeMemory();
+        _unloadStartet = 0;
+    }
 }
 
 void BauSystemBDevice::sendNextGroupTelegram()
diff --git a/src/knx/table_object.cpp b/src/knx/table_object.cpp
index cef83be..12b9222 100644
--- a/src/knx/table_object.cpp
+++ b/src/knx/table_object.cpp
@@ -58,6 +58,11 @@ void TableObject::loadState(LoadState newState)
 
     beforeStateChange(newState);
     _state = newState;
+    
+    if(newState == LS_UNLOADED)
+    {
+        _wasUnloaded = true;
+    }
 }
 
 
@@ -411,4 +416,9 @@ void TableObject::initializeDynTableProperties(size_t propertiesSize, Property**
     memcpy(allProperties + propertyCount, ownProperties, sizeof(ownProperties));
 
     InterfaceObject::initializeProperties(sizeof(allProperties), allProperties);
+}
+
+bool TableObject::getWasUnloaded()
+{
+    return _wasUnloaded;
 }
\ No newline at end of file
diff --git a/src/knx/table_object.h b/src/knx/table_object.h
index 914bb2e..da8f4f3 100644
--- a/src/knx/table_object.h
+++ b/src/knx/table_object.h
@@ -35,6 +35,8 @@ class TableObject: public InterfaceObject
         static void beforeTablesUnloadCallback(BeforeTablesUnloadCallback func);
         static BeforeTablesUnloadCallback beforeTablesUnloadCallback();
 
+        bool getWasUnloaded();
+
     protected:
         /**
          * This method is called before the interface object enters a new ::LoadState.
@@ -91,4 +93,6 @@ class TableObject: public InterfaceObject
          * The size of the memory block cannot be used because it is changed during alignment to page size.
          */
         uint32_t _size = 0;
+
+        bool _wasUnloaded = false;
 };