diff --git a/src/main/java/ch/psi/mxsc/EseraDetection.java b/src/main/java/ch/psi/mxsc/EseraDetection.java
new file mode 100644
index 0000000..d80fec3
--- /dev/null
+++ b/src/main/java/ch/psi/mxsc/EseraDetection.java
@@ -0,0 +1,58 @@
+package ch.psi.mxsc;
+
+import static ch.psi.mxsc.MainPanel.NUMBER_OF_PUCKS;
+import ch.psi.pshell.device.Device;
+import ch.psi.pshell.device.DeviceAdapter;
+import ch.psi.utils.State;
+import java.util.List;
+
+/**
+ *
+ */
+public class EseraDetection implements AutoCloseable{
+    final Device device;
+
+    public EseraDetection(Device device){  
+        this.device = device;
+        if (device!=null){
+            device.addListener(listener);
+        }        
+    }
+    
+    
+    DeviceAdapter listener = new DeviceAdapter(){
+        @Override
+        public void onStateChanged(Device device, State state, State former) {
+            if (!state.isInitialized()){
+                MainPanel.getInstance().clearPuckStates();
+            }
+        }
+
+        @Override
+        public void onValueChanged(Device device, Object value, Object former) {
+            if ((value == null) || !(value instanceof List)){
+                MainPanel.getInstance().clearPuckStates();
+            } else {
+                List l = (List)value;
+                PuckState[] puckState = MainPanel.getInstance().getPuckStates();
+                for (int i=0; i<NUMBER_OF_PUCKS; i++ ){
+                    try{
+                        List det = (List) l.get(i);
+                        puckState[i].set(det.get(0).equals(0), det.get(1).equals(0));
+                    } catch (Exception ex){
+                        puckState[i].clear();
+                    }
+                }
+                MainPanel.getInstance().repaint();
+            }
+        }
+    };
+    
+    @Override
+    public void close() {
+        if (device!=null){
+            device.removeListener(listener);
+        }
+        MainPanel.getInstance().clearPuckStates();
+    }
+}
diff --git a/src/main/java/ch/psi/mxsc/MainPanel.java b/src/main/java/ch/psi/mxsc/MainPanel.java
index 58b4f8e..d191e57 100644
--- a/src/main/java/ch/psi/mxsc/MainPanel.java
+++ b/src/main/java/ch/psi/mxsc/MainPanel.java
@@ -4,6 +4,8 @@
 
 package ch.psi.mxsc;
 
+import ch.psi.pshell.core.DevicePoolListener;
+import ch.psi.pshell.device.Device;
 import ch.psi.pshell.device.GenericDevice;
 import ch.psi.pshell.ui.Panel;
 import ch.psi.utils.swing.SwingUtils;
@@ -16,7 +18,32 @@ public class MainPanel extends Panel {
     BasePlate basePlate;
     /** Creates new form Panel */
     static MainPanel instance;
+    static String PUCK_DETECTION_DEVICE = "onewire";
     
+    public static final int NUMBER_OF_PUCKS = 30;    
+    
+    final PuckState[] puckState;
+    public PuckState[] getPuckStates(){
+        return puckState;
+    }
+    EseraDetection detection;
+    
+    //From 1 to PUCKS_NUMBER
+    public PuckState getPuckState(int id) throws Exception{
+        if ((id<=0) || (id>NUMBER_OF_PUCKS)){
+            throw new Exception("invalid puck id: "+ id);
+        }
+        return getPuckStates()[id-1];
+    }    
+    
+    public void clearPuckStates(){
+        for (PuckState puck:getPuckStates()){
+            puck.clear();
+        }
+        repaint();
+    }
+    
+        
     public static MainPanel getInstance(){
         return instance;
     }
@@ -26,20 +53,46 @@ public class MainPanel extends Panel {
         basePlate = new BasePlate();
         SwingUtils.setEnumCombo(comboMode, BasePlatePanel.Mode.class);
         comboMode.setSelectedItem(basePlatePanel.getMode());
-        this.setPersistedComponents(new Component[]{comboMode});        
+        this.setPersistedComponents(new Component[]{comboMode});
+        puckState = new PuckState[NUMBER_OF_PUCKS];
+        for (int i=0; i<NUMBER_OF_PUCKS; i++ ){
+            puckState[i] = new PuckState(i+1);
+        }
     }
     
         
     @Override
     public void onInitialize(int runCount) {        
         basePlatePanel.setDevice(basePlate);    
-        //basePlatePanel.setShowSamples(true);        
-        //puckPanel.setDevice(basePlate.getPucks()[0]);        
         GenericDevice former = getDevice("BasePlate");
         if (former!=null){
             removeDevice(former);
         }
-        addDevice(basePlate);                        
+        addDevice(basePlate);                                
+        clearPuckStates();              
+        
+        getContext().getDevicePool().addListener(new DevicePoolListener() {
+            @Override
+            public void onDeviceAdded(GenericDevice dev) {
+                if (dev.getName().equals(PUCK_DETECTION_DEVICE)){
+                    detection = new EseraDetection((Device) dev);
+                }
+            }
+            @Override
+            public void onDeviceRemoved(GenericDevice dev) {                
+                if (dev.getName().equals(PUCK_DETECTION_DEVICE)){
+                    detection.close();                    
+                    detection = null;
+                }
+            }
+        });                
+        if (detection != null){
+            detection.close();
+            detection = null;
+        }
+        if ((Device) getDevice(PUCK_DETECTION_DEVICE) != null){
+            detection = new EseraDetection((Device) getDevice(PUCK_DETECTION_DEVICE));
+        }
     }
     
     
diff --git a/src/main/java/ch/psi/mxsc/PuckDetection.java b/src/main/java/ch/psi/mxsc/PuckDetection.java
index d38e2bb..5e1736e 100644
--- a/src/main/java/ch/psi/mxsc/PuckDetection.java
+++ b/src/main/java/ch/psi/mxsc/PuckDetection.java
@@ -1,7 +1,6 @@
 package ch.psi.mxsc;
 
 
-import ch.psi.mxsc.Puck.Detection;
 import ch.psi.pshell.device.DeviceBase;
 import ch.psi.utils.Arr;
 import ch.psi.utils.Chrono;
@@ -9,92 +8,16 @@ import ch.psi.utils.State;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.logging.Level;
-import javax.swing.SwingUtilities;
 
 
-public class PuckDetection extends DeviceBase{
-    public static final int PUCKS_NUMBER = 30;
+public class PuckDetection extends DeviceBase{   
     final String server;
     public volatile Chrono chrono;
     
     public PuckDetection(String name, String server){
         super(name);
         this.server = server.startsWith("tcp://") ? server : "tcp://" + server;
-    }
-    
-    void updateGraphics(){
-        if (MainPanel.getInstance()!=null){
-            SwingUtilities.invokeLater(new Runnable() {
-                @Override
-                public void run() {
-                    MainPanel.getInstance().repaint();
-                }
-            });            
-        }
-    }
-    
-    public static class PuckState{
-        public final int id;
-        public boolean online;
-        public boolean mecSwitch;
-        public boolean indSwitch;
-        
-        PuckState(int id){
-            this.id = id;
-        }
-            
-        BasePlate getBasePlate(){
-            if (MainPanel.getInstance()==null){
-                return null;
-            }
-            return MainPanel.getInstance().basePlate;
-        }
-        
-        void clear(){
-            online = false;
-            mecSwitch = false;
-            indSwitch = false; 
-            BasePlate basePlate = getBasePlate();
-            if (basePlate!=null){
-                basePlate.getPucks()[id-1].detection = Detection.Offline;
-            }
-        }
-        void set(boolean mecSwitch, boolean indSwitch){
-            online = true;
-            this.mecSwitch = mecSwitch;
-            this.indSwitch = indSwitch;            
-            BasePlate basePlate = getBasePlate();
-            if (basePlate!=null){            
-                if (mecSwitch!=indSwitch){
-                    basePlate.getPucks()[id-1].detection = Detection.Error;
-                } else if (mecSwitch){
-                    basePlate.getPucks()[id-1].detection = Detection.Present;
-                } else {
-                    basePlate.getPucks()[id-1].detection = Detection.Empty;
-                }
-            }
-        }
-        
-        @Override
-        public String toString(){
-            return "Online = " + online + "\ns1 = " + mecSwitch+ "\ns2 = " + indSwitch;
-        }
-    }   
-    
-    PuckState[] pucks;
-    public PuckState[] getPucks(){
-        return pucks;
-    }
-    
-    //From 1 to PUCKS_NUMBER
-    public PuckState getPuck(int id) throws Exception{
-        assertInitialized();
-        if ((id<=0) || (id>PUCKS_NUMBER)){
-            throw new Exception("invalid puck id: "+ id);
-        }
-        return pucks[id-1];
-    }
-    
+    }        
     
     Thread thread;
     Thread watchDog;
@@ -104,10 +27,6 @@ public class PuckDetection extends DeviceBase{
         doClose();
         super.doInitialize();        
         
-        pucks = new PuckState[PUCKS_NUMBER];
-        for (int i=0; i<PUCKS_NUMBER; i++ ){
-            pucks[i] = new PuckState(i+1);
-        }
         chrono = new Chrono();
         thread = new Thread(new Runnable() {
             @Override
@@ -125,11 +44,8 @@ public class PuckDetection extends DeviceBase{
                     while (!Thread.currentThread().isInterrupted()) {
                         if (chrono.isTimeout(3000)){
                             setState(State.Offline);
-                            for (PuckState puck:pucks){
-                                puck.clear();
-                            }                    
-                        }
-                        updateGraphics();
+                            MainPanel.getInstance().clearPuckStates();
+                        }                        
                         Thread.sleep(1000);
                     }
                 } catch (Exception ex){
@@ -156,15 +72,14 @@ public class PuckDetection extends DeviceBase{
                     String contents = subscriber.recvStr();
                     System.out.println(contents);
                     processMessage(contents);
-                    updateGraphics();
+                    if (MainPanel.getInstance()!=null){
+                        MainPanel.getInstance().repaint();
+                    }
                     setState(State.Ready);
                     chrono = new Chrono();
                 }
             } finally{
-                for (PuckState puck:pucks){
-                    puck.clear();
-                }
-                updateGraphics();
+                MainPanel.getInstance().clearPuckStates();                
                 subscriber.close();
                 context.term();                                        
             }
@@ -182,7 +97,7 @@ public class PuckDetection extends DeviceBase{
                 String[] tokens = line.split("  ");
                 int id = Integer.valueOf(tokens[0].substring(1));
                 present.add(id);
-                PuckState puck = getPuck(id);
+                PuckState puck = MainPanel.getInstance().getPuckState(id);
                 if (tokens.length<3){
                     puck.clear();
                 } else {
@@ -192,9 +107,13 @@ public class PuckDetection extends DeviceBase{
                 getLogger().log(Level.INFO, null, ex);
             }
         }
-        for (int i=1; i<= PUCKS_NUMBER; i++){
+        for (int i=1; i<= MainPanel.NUMBER_OF_PUCKS; i++){
             if (!Arr.containsEqual(present.toArray(), i)){
-                pucks[i-1].clear();
+                try{
+                    MainPanel.getInstance().getPuckState(i).clear();
+                } catch (Exception ex){
+                    getLogger().log(Level.INFO, null, ex);
+                }                    
             }
         }
     }
diff --git a/src/main/java/ch/psi/mxsc/PuckState.java b/src/main/java/ch/psi/mxsc/PuckState.java
new file mode 100644
index 0000000..313cccc
--- /dev/null
+++ b/src/main/java/ch/psi/mxsc/PuckState.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2014 Paul Scherrer Institute. All rights reserved.
+ */
+package ch.psi.mxsc;
+
+/**
+ *
+ */
+public class PuckState {
+    
+    public final int id;
+    public boolean online;
+    public boolean mecSwitch;
+    public boolean indSwitch;
+
+    PuckState(int id) {
+        this.id = id;
+    }
+
+    BasePlate getBasePlate() {
+        if (MainPanel.getInstance() == null) {
+            return null;
+        }
+        return MainPanel.getInstance().basePlate;
+    }
+
+    void clear() {
+        online = false;
+        mecSwitch = false;
+        indSwitch = false;
+        BasePlate basePlate = getBasePlate();
+        if (basePlate != null) {
+            basePlate.getPucks()[id - 1].detection = Puck.Detection.Offline;
+        }
+    }
+
+    void set(boolean mecSwitch, boolean indSwitch) {
+        online = true;
+        this.mecSwitch = mecSwitch;
+        this.indSwitch = indSwitch;
+        BasePlate basePlate = getBasePlate();
+        if (basePlate != null) {
+            if (mecSwitch != indSwitch) {
+                basePlate.getPucks()[id - 1].detection = Puck.Detection.Error;
+            } else if (mecSwitch) {
+                basePlate.getPucks()[id - 1].detection = Puck.Detection.Present;
+            } else {
+                basePlate.getPucks()[id - 1].detection = Puck.Detection.Empty;
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "Online = " + online + "\ns1 = " + mecSwitch + "\ns2 = " + indSwitch;
+    }
+    
+}