diff --git a/src/main/java/ch/psi/mxsc/PuckDetection.java b/src/main/java/ch/psi/mxsc/PuckDetection.java
index 44f1dc0..36c2358 100644
--- a/src/main/java/ch/psi/mxsc/PuckDetection.java
+++ b/src/main/java/ch/psi/mxsc/PuckDetection.java
@@ -164,9 +164,11 @@ public class PuckDetection extends DeviceBase {
                 for (List<Integer> sensor : bus) {
                     Integer indDetector = sensor.get(0);
                     Integer mecDetector = sensor.get(1);
-                    int index = Controller.getInstance().getPuckIndex(address);
-                    PuckState puck = Controller.getInstance().getPuckState(index);
-                    puck.set(mecDetector, indDetector);
+                    if (Controller.getInstance()!=null){
+                        int index = Controller.getInstance().getPuckIndex(address);
+                        PuckState puck = Controller.getInstance().getPuckState(index);
+                        puck.set(mecDetector, indDetector);
+                    }                    
                     address++;
                 }
             }            
@@ -177,10 +179,16 @@ public class PuckDetection extends DeviceBase {
     }
         
     public PuckState getPuckState(int id) throws Exception {        
+        if (Controller.getInstance() == null) {
+            return null;
+        }
         return Controller.getInstance().getPuckState(id);
     }
     
-    public Puck getPuck(String name) throws Exception {        
+    public Puck getPuck(String name) throws Exception {   
+        if (Controller.getInstance() == null) {
+            return null;
+        }        
         return Controller.getInstance().getPuck(name);
     }
     
@@ -204,8 +212,9 @@ public class PuckDetection extends DeviceBase {
     }
 
     public static void main(String[] args) throws IOException, InterruptedException {
-        PuckDetection pd = new PuckDetection("PD", "129.129.110.99:5556");
+        //PuckDetection pd = new PuckDetection("PD", "129.129.110.99:5556");
         //PuckDetection pd = new PuckDetection("PD","raspberrypi:5556");
+        PuckDetection pd = new PuckDetection("PD", "tell10s-raspberrypi:5556");
         pd.setDebug(true);
         pd.initialize();
         Thread.sleep(100000);