diff --git a/examples/sky-shell/src/se/sics/contiki/collect/CollectServer.java b/examples/sky-shell/src/se/sics/contiki/collect/CollectServer.java
index 1b68cc2c4..67108c88b 100644
--- a/examples/sky-shell/src/se/sics/contiki/collect/CollectServer.java
+++ b/examples/sky-shell/src/se/sics/contiki/collect/CollectServer.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: CollectServer.java,v 1.6 2008/08/29 09:00:15 nifi Exp $
+ * $Id: CollectServer.java,v 1.7 2008/08/29 10:00:23 nifi Exp $
  *
  * -----------------------------------------------------------------
  *
@@ -34,8 +34,8 @@
  *
  * Authors : Joakim Eriksson, Niclas Finne
  * Created : 3 jul 2008
- * Updated : $Date: 2008/08/29 09:00:15 $
- *           $Revision: 1.6 $
+ * Updated : $Date: 2008/08/29 10:00:23 $
+ *           $Revision: 1.7 $
  */
 
 package se.sics.contiki.collect;
@@ -538,7 +538,7 @@ public class CollectServer {
 
       @Override
       protected void serialData(String line) {
-        parseIncomingLine(line);
+        parseIncomingLine(System.currentTimeMillis(), line);
       }
 
     };
@@ -569,6 +569,10 @@ public class CollectServer {
     if (serialConnection != null) {
       serialConnection.close();
     }
+    PrintWriter output = this.sensorDataOutput;
+    if (output != null) {
+      output.close();
+    }
     System.exit(0);
   }
 
@@ -820,8 +824,8 @@ public class CollectServer {
     return false;
   }
 
-  protected void parseIncomingLine(String line) {
-    SensorData sensorData = SensorData.parseSensorData(this, line);
+  protected void parseIncomingLine(long systemTime, String line) {
+    SensorData sensorData = SensorData.parseSensorData(this, line, systemTime);
     if (sensorData != null) {
       // Sensor data received
       handleSensorData(sensorData);
@@ -869,7 +873,7 @@ public class CollectServer {
       Node source = sensorData.getNode();
       Link link = source.getLink(neighbor);
       link.setETX(sensorData.getBestNeighborETX());
-      link.setLastActive(sensorData.getTime());
+      link.setLastActive(sensorData.getNodeTime());
     }
   }
 
@@ -924,6 +928,7 @@ public class CollectServer {
     }
     if (output != null) {
       output.println(data.toString());
+      output.flush();
     }
   }
 
diff --git a/examples/sky-shell/src/se/sics/contiki/collect/Node.java b/examples/sky-shell/src/se/sics/contiki/collect/Node.java
index 69faade58..ad959759e 100644
--- a/examples/sky-shell/src/se/sics/contiki/collect/Node.java
+++ b/examples/sky-shell/src/se/sics/contiki/collect/Node.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: Node.java,v 1.2 2008/08/29 09:00:15 nifi Exp $
+ * $Id: Node.java,v 1.3 2008/08/29 10:00:23 nifi Exp $
  *
  * -----------------------------------------------------------------
  *
@@ -34,8 +34,8 @@
  *
  * Authors : Joakim Eriksson, Niclas Finne
  * Created : 3 jul 2008
- * Updated : $Date: 2008/08/29 09:00:15 $
- *           $Revision: 1.2 $
+ * Updated : $Date: 2008/08/29 10:00:23 $
+ *           $Revision: 1.3 $
  */
 
 package se.sics.contiki.collect;
@@ -168,9 +168,9 @@ public class Node implements Comparable<Node> {
     if (sensorDataList.size() > 0) {
       SensorData last = sensorDataList.get(sensorDataList.size() - 1);
       // TODO should check seqno!
-      if (data.getTime() <= last.getTime()) {
+      if (data.getNodeTime() <= last.getNodeTime()) {
         // Sensor data already added
-        System.out.println("SensorData: ignoring (time " + (data.getTime() - last.getTime())
+        System.out.println("SensorData: ignoring (time " + (data.getNodeTime() - last.getNodeTime())
             + "msec): " + data);
         return false;
       }
diff --git a/examples/sky-shell/src/se/sics/contiki/collect/SensorData.java b/examples/sky-shell/src/se/sics/contiki/collect/SensorData.java
index 2d9edd2cf..f2f763242 100644
--- a/examples/sky-shell/src/se/sics/contiki/collect/SensorData.java
+++ b/examples/sky-shell/src/se/sics/contiki/collect/SensorData.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: SensorData.java,v 1.3 2008/08/29 09:00:15 nifi Exp $
+ * $Id: SensorData.java,v 1.4 2008/08/29 10:00:23 nifi Exp $
  *
  * -----------------------------------------------------------------
  *
@@ -34,11 +34,12 @@
  *
  * Authors : Joakim Eriksson, Niclas Finne
  * Created : 3 jul 2008
- * Updated : $Date: 2008/08/29 09:00:15 $
- *           $Revision: 1.3 $
+ * Updated : $Date: 2008/08/29 10:00:23 $
+ *           $Revision: 1.4 $
  */
 
 package se.sics.contiki.collect;
+import java.util.Arrays;
 
 /**
  *
@@ -47,12 +48,14 @@ public class SensorData implements SensorInfo {
 
   private final Node node;
   private final int[] values;
-  private final long time;
+  private final long nodeTime;
+  private final long systemTime;
 
-  public SensorData(Node node, int[] values) {
+  public SensorData(Node node, int[] values, long systemTime) {
     this.node = node;
     this.values = values;
-    this.time = ((values[TIMESTAMP1] << 16) + values[TIMESTAMP2]) * 1000L;
+    this.nodeTime = ((values[TIMESTAMP1] << 16) + values[TIMESTAMP2]) * 1000L;
+    this.systemTime = systemTime;
   }
 
   public Node getNode() {
@@ -71,12 +74,19 @@ public class SensorData implements SensorInfo {
     return values.length;
   }
 
-  public long getTime() {
-    return time;
+  public long getNodeTime() {
+    return nodeTime;
+  }
+
+  public long getSystemTime() {
+    return systemTime;
   }
 
   public String toString() {
     StringBuilder sb = new StringBuilder();
+    if (systemTime > 0L) {
+      sb.append(systemTime).append(' ');
+    }
     for (int i = 0, n = values.length; i < n; i++) {
       if (i > 0) sb.append(' ');
       sb.append(values[i]);
@@ -85,7 +95,20 @@ public class SensorData implements SensorInfo {
   }
 
   public static SensorData parseSensorData(CollectServer server, String line) {
+    return parseSensorData(server, line, 0);
+  }
+
+  public static SensorData parseSensorData(CollectServer server, String line, long systemTime) {
     String[] components = line.split(" ");
+    if (components.length == SensorData.VALUES_COUNT + 1) {
+      // Sensor data with system time
+      try {
+        systemTime = Long.parseLong(components[0]);
+        components = Arrays.copyOfRange(components, 1, components.length);
+      } catch (NumberFormatException e) {
+        // First column does not seem to be system time
+      }
+    }
     if (components.length != SensorData.VALUES_COUNT) {
       return null;
     }
@@ -97,7 +120,7 @@ public class SensorData implements SensorInfo {
     }
     String nodeID = mapNodeID(data[NODE_ID]);
     Node node = server.addNode(nodeID);
-    return new SensorData(node, data);
+    return new SensorData(node, data, systemTime);
   }
 
   public static String mapNodeID(int nodeID) {
diff --git a/examples/sky-shell/src/se/sics/contiki/collect/gui/TimeChartPanel.java b/examples/sky-shell/src/se/sics/contiki/collect/gui/TimeChartPanel.java
index 5c38aa957..63d10db66 100644
--- a/examples/sky-shell/src/se/sics/contiki/collect/gui/TimeChartPanel.java
+++ b/examples/sky-shell/src/se/sics/contiki/collect/gui/TimeChartPanel.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: TimeChartPanel.java,v 1.2 2008/08/29 08:42:30 nifi Exp $
+ * $Id: TimeChartPanel.java,v 1.3 2008/08/29 10:00:23 nifi Exp $
  *
  * -----------------------------------------------------------------
  *
@@ -34,8 +34,8 @@
  *
  * Authors : Joakim Eriksson, Niclas Finne
  * Created : 3 jul 2008
- * Updated : $Date: 2008/08/29 08:42:30 $
- *           $Revision: 1.2 $
+ * Updated : $Date: 2008/08/29 10:00:23 $
+ *           $Revision: 1.3 $
  */
 
 package se.sics.contiki.collect.gui;
@@ -147,7 +147,7 @@ public abstract class TimeChartPanel extends JPanel implements Visualizer {
             series.clear();
             updateSeries(series, node, groupSize);
           } else {
-            series.addOrUpdate(new Second(new Date(data.getTime())), getSensorDataValue(data));
+            series.addOrUpdate(new Second(new Date(data.getNodeTime())), getSensorDataValue(data));
           }
           chartPanel.repaint();
           break;
@@ -175,7 +175,7 @@ public abstract class TimeChartPanel extends JPanel implements Visualizer {
         } else {
           for (int i = 0, n = node.getSensorDataCount(); i < n; i++) {
             SensorData data = node.getSensorData(i);
-            series.addOrUpdate(new Second(new Date(data.getTime())), getSensorDataValue(data));
+            series.addOrUpdate(new Second(new Date(data.getNodeTime())), getSensorDataValue(data));
           }
         }
         timeSeries.addSeries(series);
@@ -204,7 +204,7 @@ public abstract class TimeChartPanel extends JPanel implements Visualizer {
       for (int j = 0; j < groupSize; j++) {
         SensorData data = node.getSensorData(i);
         value += getSensorDataValue(data);
-        time += data.getTime() / 1000L;
+        time += data.getNodeTime() / 1000L;
       }
       series.addOrUpdate(new Second(new Date((time / groupSize) * 1000L)), value / groupSize);
     }