diff --git a/Modules/IGT/Testing/mitkOpenIGTLinkTrackingDeviceTest.cpp b/Modules/IGT/Testing/mitkOpenIGTLinkTrackingDeviceTest.cpp
index 715d3261e2..9cf52ea47b 100644
--- a/Modules/IGT/Testing/mitkOpenIGTLinkTrackingDeviceTest.cpp
+++ b/Modules/IGT/Testing/mitkOpenIGTLinkTrackingDeviceTest.cpp
@@ -1,81 +1,84 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 //testing headers
 #include <mitkTestingMacros.h>
 #include <mitkTestFixture.h>
 
 //headers of IGT classes releated to the tested class
 #include <mitkOpenIGTLinkTrackingDevice.h>
 
 
 class mitkOpenIGTLinkTrackingDeviceTestSuite : public mitk::TestFixture
 {
   CPPUNIT_TEST_SUITE(mitkOpenIGTLinkTrackingDeviceTestSuite);
   MITK_TEST(TestInstantiation);
   MITK_TEST(TestSetConnectionParameters);
   MITK_TEST(TestDiscoverToolMethod);
   CPPUNIT_TEST_SUITE_END();
 
 private:
   /** Members used inside the different test methods. All members are initialized via setUp().*/
   mitk::OpenIGTLinkTrackingDevice::Pointer m_OpenIGTLinkTrackingDevice;
 
 public:
 
   /**@brief Setup Always call this method before each Test-case to ensure correct and new intialization of the used members for a new test case. (If the members are not used in a test, the method does not need to be called).*/
   void setUp()
   {
     m_OpenIGTLinkTrackingDevice = mitk::OpenIGTLinkTrackingDevice::New();
   }
 
   void tearDown()
   {
   }
 
   void TestInstantiation()
   {
   // let's create objects of our classes
   mitk::OpenIGTLinkTrackingDevice::Pointer testDevice = mitk::OpenIGTLinkTrackingDevice::New();
   CPPUNIT_ASSERT_MESSAGE("Testing instantiation of OpenIGTLinkTrackingDevice",testDevice.IsNotNull());
   }
 
   void TestSetConnectionParameters()
   {
     m_OpenIGTLinkTrackingDevice->SetHostname("localhost");
     m_OpenIGTLinkTrackingDevice->SetPortNumber(10);
     CPPUNIT_ASSERT_MESSAGE("Testing method SetHostname() ...", m_OpenIGTLinkTrackingDevice->GetHostname()=="localhost");
     CPPUNIT_ASSERT_MESSAGE("Testing method SetPort() ...", m_OpenIGTLinkTrackingDevice->GetPortNumber()==10);
   }
 
   void TestDiscoverToolMethod()
   {
   CPPUNIT_ASSERT_MESSAGE("Testing DiscoverTools() without initialization. (Warnings are expected)", m_OpenIGTLinkTrackingDevice->DiscoverTools()==false);
   m_OpenIGTLinkTrackingDevice->SetPortNumber(10);
   CPPUNIT_ASSERT_MESSAGE("Testing DiscoverTools() with initialization, but without existing server. (Warnings are expected)", m_OpenIGTLinkTrackingDevice->DiscoverTools()==false);
 
   m_OpenIGTLinkTrackingDevice->SetHostname("193.174.50.103");
   m_OpenIGTLinkTrackingDevice->SetPortNumber(18944);
-  m_OpenIGTLinkTrackingDevice->DiscoverTools();
+  m_OpenIGTLinkTrackingDevice->DiscoverTools(20000);
   m_OpenIGTLinkTrackingDevice->OpenConnection();
   m_OpenIGTLinkTrackingDevice->StartTracking();
 
   Sleep(20000);
 
+  m_OpenIGTLinkTrackingDevice->StopTracking();
+  m_OpenIGTLinkTrackingDevice->CloseConnection();
+
   }
 
 };
 MITK_TEST_SUITE_REGISTRATION(mitkOpenIGTLinkTrackingDevice)
diff --git a/Modules/IGT/TrackingDevices/mitkOpenIGTLinkTrackingDevice.cpp b/Modules/IGT/TrackingDevices/mitkOpenIGTLinkTrackingDevice.cpp
index b4649da2f2..6da7470a30 100644
--- a/Modules/IGT/TrackingDevices/mitkOpenIGTLinkTrackingDevice.cpp
+++ b/Modules/IGT/TrackingDevices/mitkOpenIGTLinkTrackingDevice.cpp
@@ -1,302 +1,361 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include "mitkOpenIGTLinkTrackingDevice.h"
 #include "mitkOpenIGTLinkTrackingTool.h"
 #include "mitkIGTConfig.h"
 #include "mitkIGTTimeStamp.h"
 #include "mitkIGTHardwareException.h"
 #include "mitkTrackingTypes.h"
 #include <itksys/SystemTools.hxx>
 #include <iostream>
 #include <itkMutexLockHolder.h>
 #include <itkCommand.h>
 #include <igtlTrackingDataMessage.h>
 
 typedef itk::MutexLockHolder<itk::FastMutexLock> MutexLockHolder;
 
 
 mitk::OpenIGTLinkTrackingDevice::OpenIGTLinkTrackingDevice(): mitk::TrackingDevice()
 {
   //set the type of this tracking device
   this->m_Data = mitk::DeviceDataOpenIGTLinkTrackingDeviceConnection;
 
   this->m_MultiThreader = itk::MultiThreader::New();
   m_ThreadID = 0;
 
   m_OpenIGTLinkClient = mitk::IGTLClient::New();
   m_OpenIGTLinkClient->EnableInfiniteBufferingMode(m_OpenIGTLinkClient->GetReceiveQueue(),false);
   m_OpenIGTLinkClient->SetName("OpenIGTLink Tracking Device");
 
   m_IGTLDeviceSource =  mitk::IGTLDeviceSource::New();
   m_IGTLDeviceSource->SetIGTLDevice(m_OpenIGTLinkClient);
 
 }
 
 
 mitk::OpenIGTLinkTrackingDevice::~OpenIGTLinkTrackingDevice()
 {
 }
 
 int mitk::OpenIGTLinkTrackingDevice::GetPortNumber()
 {
   return m_OpenIGTLinkClient->GetPortNumber();
 }
 
 std::string mitk::OpenIGTLinkTrackingDevice::GetHostname()
 {
   return m_OpenIGTLinkClient->GetHostname();
 }
 
 
 void mitk::OpenIGTLinkTrackingDevice::SetPortNumber(int portNumber)
 {
   m_OpenIGTLinkClient->SetPortNumber(portNumber);
 }
 
 void mitk::OpenIGTLinkTrackingDevice::SetHostname(std::string hostname)
 {
   m_OpenIGTLinkClient->SetHostname(hostname);
 }
 
 mitk::TrackingTool* mitk::OpenIGTLinkTrackingDevice::AddTool( const char* toolName, const char* fileName )
 {
   mitk::OpenIGTLinkTrackingTool::Pointer t;// = mitk::OpenIGTLinkTrackingTool::New();
   //TODO: Implement
   if (this->InternalAddTool(t) == false)
     return NULL;
   return t.GetPointer();
 }
 
 
 bool mitk::OpenIGTLinkTrackingDevice::InternalAddTool(OpenIGTLinkTrackingTool::Pointer tool)
 {
   m_AllTools.push_back(tool);
   return true;
 }
 
 
 bool mitk::OpenIGTLinkTrackingDevice::DiscoverTools(int WaitingTime)
 {
   if (m_OpenIGTLinkClient->GetPortNumber() == -1)
     {
     MITK_WARN << "Connection not initialized, aborting (invalid port number).";
     return false;
     }
 
   try
     {
     m_IGTLDeviceSource->Connect();
     m_IGTLDeviceSource->StartCommunication();
     }
   catch(std::runtime_error &e)
     {
     MITK_WARN << "Open IGT Link device retruned an error while trying to connect: " << e.what();
     return false;
     }
 
   //send a message to the server: start tracking stream
   mitk::IGTLMessageFactory::Pointer msgFactory = m_OpenIGTLinkClient->GetMessageFactory();
   std::string message = "STT_TDATA";
   //m_OpenIGTLinkClient->SendMessage(msgFactory->CreateInstance(message));
 
-  //Sleep(WaitingTime); //wait for data to arrive
+  Sleep(WaitingTime); //wait for data to arrive
 
-  Sleep(20000);
   m_IGTLDeviceSource->Update();
 
   //check the tracking stream for the number and type of tools
   //igtl::MessageBase::Pointer receivedMessage = m_OpenIGTLinkClient->GetNextMessage();
   mitk::IGTLMessage::Pointer receivedMessage = m_IGTLDeviceSource->GetOutput();
   if (receivedMessage.IsNull())
     {
     MITK_WARN << "No message was received. Is there really a server?";
     return false;
     }
   else if (!receivedMessage->IsDataValid())
     {
     MITK_WARN << "Received invalid message.";
     return false;
     }
 
   const char* msgType = receivedMessage->GetIGTLMessageType();
 
   if( !(strcmp(msgType,"TDATA") == 0) )
     {
     MITK_INFO << "Server does not send tracking data. Received data is not of the type TDATA. Received type: " << msgType;
     return true;
     }
 
 
   igtl::TrackingDataMessage* tdMsg = (igtl::TrackingDataMessage*)(receivedMessage->GetMessage().GetPointer());
 
   if(!tdMsg)
     {
      MITK_WARN << "Cannot cast message object as expected, aborting!";
      return false;
     }
 
   int numberOfTools = tdMsg->GetNumberOfTrackingDataElements();
   MITK_INFO << "Found " << numberOfTools << " tools";
   for(int i=0; i<numberOfTools; i++)
     {
     mitk::OpenIGTLinkTrackingTool::Pointer newTool = mitk::OpenIGTLinkTrackingTool::New();
     igtl::TrackingDataElement::Pointer currentTrackingData;
     tdMsg->GetTrackingDataElement(i,currentTrackingData);
     std::string name = currentTrackingData->GetName();
     if (name == "") //if no name was given create a default name
       {
       std::stringstream defaultName;
       defaultName << "OpenIGTLinkTool#" << i;
       name = defaultName.str();
       }
     MITK_INFO << "Added tool " << name << " to tracking device.";
     newTool->SetToolName(name);
     this->InternalAddTool(newTool);
     }
 
+  m_IGTLDeviceSource->StopCommunication();
+  this->SetState(Ready);
   return true;
 }
 
 void mitk::OpenIGTLinkTrackingDevice::UpdateTools()
 {
+  if (this->GetState() != Tracking)
+    {
+    MITK_ERROR << "Method was called in the wrong state, something went wrong!";
+    return;
+    }
+
   m_IGTLMsgToNavDataFilter->Update();
   for (int i=0; i<this->GetToolCount(); i++)
   {
     mitk::NavigationData::Pointer currentNavData = m_IGTLMsgToNavDataFilter->GetOutput(i);
     m_AllTools.at(i)->SetDataValid(currentNavData->IsDataValid());
     m_AllTools.at(i)->SetPosition(currentNavData->GetPosition());
     m_AllTools.at(i)->SetOrientation(currentNavData->GetOrientation());
     m_AllTools.at(i)->SetIGTTimeStamp(currentNavData->GetIGTTimeStamp());
 
 
     mitk::Point3D pos;
     m_AllTools.at(i)->GetPosition(pos);
 
     MITK_INFO << "Updated Tool " << i << " Pos: " << pos;
   }
 
 }
 
 
 bool mitk::OpenIGTLinkTrackingDevice::StartTracking()
 {
-  // todo: check tracking state
+   //check tracking state
+   if (this->GetState() != Ready)
+    {
+    MITK_WARN << "Cannot start tracking, device is not ready!";
+    return false;
+    }
+
    try
     {
     m_IGTLDeviceSource->StartCommunication();
+
+    //send a message to the server: start tracking stream
+    mitk::IGTLMessageFactory::Pointer msgFactory = m_OpenIGTLinkClient->GetMessageFactory();
+    std::string message = "STT_TDATA";
+    //m_OpenIGTLinkClient->SendMessage(msgFactory->CreateInstance(message));
     }
   catch(std::runtime_error &e)
     {
     MITK_WARN << "Open IGT Link device retruned an error while starting communication: " << e.what();
     return false;
     }
 
   //create internal igtl pipeline
   m_IGTLMsgToNavDataFilter =  mitk::IGTLMessageToNavigationDataFilter::New();
   m_IGTLMsgToNavDataFilter->SetNumberOfExpectedOutputs(this->GetToolCount());
   m_IGTLMsgToNavDataFilter->ConnectTo(m_IGTLDeviceSource);
 
 
   //connect itk events
   typedef itk::SimpleMemberCommand< mitk::OpenIGTLinkTrackingDevice > CurCommandType;
   CurCommandType::Pointer messageReceivedCommand = CurCommandType::New();
   messageReceivedCommand->SetCallbackFunction(this, &mitk::OpenIGTLinkTrackingDevice::UpdateTools);
   m_MessageReceivedObserverTag = m_OpenIGTLinkClient->AddObserver(mitk::MessageReceivedEvent(),messageReceivedCommand);
 
-  return false;
+  this->SetState(Tracking);
+  return true;
 }
 
 
 bool mitk::OpenIGTLinkTrackingDevice::StopTracking()
 {
+  //check tracking state
+  if (this->GetState() != Tracking)
+    {
+    MITK_WARN << "Cannot open connection, device is already connected!";
+    return false;
+    }
+
   m_OpenIGTLinkClient->RemoveObserver(m_MessageReceivedObserverTag); //disconnect itk events
 
-  Superclass::StopTracking();
+  try
+    {
+    m_IGTLDeviceSource->StopCommunication();
+    }
+  catch(std::runtime_error &e)
+    {
+    MITK_WARN << "Open IGT Link device retruned an error while stopping communication: " << e.what();
+    return false;
+    }
+  this->SetState(Ready);
   return true;
 }
 
 
 unsigned int mitk::OpenIGTLinkTrackingDevice::GetToolCount() const
 {
   return (unsigned int)this->m_AllTools.size();
 }
 
 
 mitk::TrackingTool* mitk::OpenIGTLinkTrackingDevice::GetTool(unsigned int toolNumber) const
 {
   if ( toolNumber >= this->GetToolCount())
     return NULL;
   else
     return this->m_AllTools[toolNumber];
 }
 
 
 bool mitk::OpenIGTLinkTrackingDevice::OpenConnection()
 {
+  //check tracking state
+  if (this->GetState() != Setup)
+    {
+    MITK_WARN << "Cannot open connection, device is already connected!";
+    return false;
+    }
+
   try
     {
     m_IGTLDeviceSource->Connect();
     }
   catch(std::runtime_error &e)
     {
     MITK_WARN << "Open IGT Link device retruned an error while trying to connect: " << e.what();
     return false;
     }
-
+  this->SetState(Ready);
   return true;
 }
 
 
 bool mitk::OpenIGTLinkTrackingDevice::CloseConnection()
 {
-  bool returnValue = false;
-  //TODO: Implement
-  return returnValue;
+  //check tracking state
+  if (this->GetState() != Ready)
+    {
+    MITK_WARN << "Cannot close connection, device is in the wrong state!";
+    return false;
+    }
+
+  try
+    {
+    m_IGTLDeviceSource->Disconnect();
+    }
+  catch(std::runtime_error &e)
+    {
+    MITK_WARN << "Open IGT Link device retruned an error while trying to disconnect: " << e.what();
+    return false;
+    }
+
+  this->SetState(Setup);
+
+  return true;
 }
 
 std::vector<mitk::OpenIGTLinkTrackingTool::Pointer> mitk::OpenIGTLinkTrackingDevice::GetAllTools()
 {
   return this->m_AllTools;
 }
 
 
 void mitk::OpenIGTLinkTrackingDevice::TrackTools()
 {
   //TODO: Implement
 }
 
 
 
 ITK_THREAD_RETURN_TYPE mitk::OpenIGTLinkTrackingDevice::ThreadStartTracking(void* pInfoStruct)
 {
   /* extract this pointer from Thread Info structure */
   struct itk::MultiThreader::ThreadInfoStruct * pInfo = (struct itk::MultiThreader::ThreadInfoStruct*)pInfoStruct;
   if (pInfo == NULL)
   {
     return ITK_THREAD_RETURN_VALUE;
   }
   if (pInfo->UserData == NULL)
   {
     return ITK_THREAD_RETURN_VALUE;
   }
   OpenIGTLinkTrackingDevice *trackingDevice = (OpenIGTLinkTrackingDevice*)pInfo->UserData;
 
   if (trackingDevice != NULL)
     trackingDevice->TrackTools();
 
   return ITK_THREAD_RETURN_VALUE;
 }