diff --git a/Lora-Map/Model/AlarmItem.cs b/Lora-Map/Model/AlarmItem.cs
index 36c3854..83c02fa 100644
--- a/Lora-Map/Model/AlarmItem.cs
+++ b/Lora-Map/Model/AlarmItem.cs
@@ -1,81 +1,32 @@
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using LitJson;
 
 namespace Fraunhofer.Fit.IoT.LoraMap.Model {
-  class AlarmItem {
-    public Double Rssi { get; private set; }
-    public Double Snr { get; private set; }
-    public DateTime Lorarecievedtime { get; private set; }
-    public DateTime Recievedtime { get; private set; }
-    public Double Latitude { get; private set; }
-    public Double Longitude { get; private set; }
-    public UTMData UTM { get; private set; }
-    public Double Hdop { get; private set; }
-    public Boolean Fix { get; private set; }
-    public Double Height { get; private set; }
-    public List<DateTime> ButtonPressed => this.buttonhistory.Keys.ToList();
-
+  public class AlarmItem : PositionItem {
     private readonly SortedDictionary<DateTime, String> buttonhistory = new SortedDictionary<DateTime, String>();
 
-    public AlarmItem(JsonData json) => this.Update(json);
+    public List<DateTime> ButtonPressed => this.buttonhistory.Keys.ToList();
 
-    public void Update(JsonData json) {
-      this.Rssi = json["Rssi"].IsInt ? (Int32)json["Rssi"] : (Double)json["Rssi"];
-      this.Snr = json["Snr"].IsInt ? (Int32)json["Snr"] : (Double)json["Snr"];
-      if (DateTime.TryParse((String)json["Receivedtime"], DateTimeFormatInfo.InvariantInfo, DateTimeStyles.AssumeUniversal, out DateTime updatetime)) {
-        this.Lorarecievedtime = updatetime.ToUniversalTime();
-      }
-      this.Recievedtime = DateTime.UtcNow;
-      this.Latitude = json["Gps"]["Latitude"].IsInt ? (Int32)json["Gps"]["Latitude"] : (Double)json["Gps"]["Latitude"];
-      this.Longitude = json["Gps"]["Longitude"].IsInt ? (Int32)json["Gps"]["Longitude"] : (Double)json["Gps"]["Longitude"];
-      this.Fix = (Boolean)json["Gps"]["Fix"];
-      if (!this.Fix) {
-        this.Latitude = json["Gps"]["LastLatitude"].IsInt ? (Int32)json["Gps"]["LastLatitude"] : (Double)json["Gps"]["LastLatitude"];
-        this.Longitude = json["Gps"]["LastLongitude"].IsInt ? (Int32)json["Gps"]["LastLongitude"] : (Double)json["Gps"]["LastLongitude"];
-      }
-      this.UTM = new UTMData(this.Latitude, this.Longitude);
-      this.Hdop = json["Gps"]["Hdop"].IsInt ? (Int32)json["Gps"]["Hdop"] : (Double)json["Gps"]["Hdop"];
-      this.Height = json["Gps"]["Height"].IsInt ? (Int32)json["Gps"]["Height"] : (Double)json["Gps"]["Height"];
+    public AlarmItem(JsonData json) : base(json, null) {
+    }
+
+    public override void Update(JsonData json) {
+      base.Update(json);
       this.SetHistory(json);
     }
 
     private void SetHistory(JsonData json) {
-      String key = json["BatteryLevel"].ToString();
-      key += "_" + json["Calculatedcrc"].ToString();
-      key += "_" + json["Gps"]["Hdop"].ToString();
-      key += "_" + json["Gps"]["Height"].ToString();
-      key += "_" + json["Gps"]["Fix"].ToString();
-      key += "_" + json["Gps"]["LastLatitude"].ToString();
-      key += "_" + json["Gps"]["LastLongitude"].ToString();
-      key += "_" + json["Gps"]["Time"].ToString();
-      if(!this.buttonhistory.ContainsValue(key)) {
-        this.buttonhistory.Add(DateTime.UtcNow, key);
-        if(this.buttonhistory.Count > 10) {
-          this.buttonhistory.Remove(this.buttonhistory.Keys.ToList().First());
+      if(json.ContainsKey("Hash") && json["Hash"].IsString) {
+        String key = json["Hash"].ToString();
+        if(!this.buttonhistory.ContainsValue(key)) {
+          this.buttonhistory.Add(DateTime.UtcNow, key);
+          if(this.buttonhistory.Count > 10) {
+            _ = this.buttonhistory.Remove(this.buttonhistory.Keys.ToList().First());
+          }
         }
-      }
+      }      
     }
-
-    public static String GetId(JsonData json) => (String)json["Name"];
-
-    public static Boolean CheckJson(JsonData json) =>
-      json.ContainsKey("Rssi") && (json["Rssi"].IsDouble || json["Rssi"].IsInt)
-      && json.ContainsKey("Snr") && (json["Snr"].IsDouble || json["Snr"].IsInt)
-      && json.ContainsKey("Receivedtime") && json["Receivedtime"].IsString
-      && json.ContainsKey("BatteryLevel") && (json["BatteryLevel"].IsDouble || json["BatteryLevel"].IsInt)
-      && json.ContainsKey("Gps") && json["Gps"].IsObject
-      && json["Gps"].ContainsKey("Latitude") && (json["Gps"]["Latitude"].IsDouble || json["Gps"]["Latitude"].IsInt)
-      && json["Gps"].ContainsKey("Longitude") && (json["Gps"]["Longitude"].IsDouble || json["Gps"]["Longitude"].IsInt)
-      && json["Gps"].ContainsKey("LastLatitude") && (json["Gps"]["LastLatitude"].IsDouble || json["Gps"]["LastLatitude"].IsInt)
-      && json["Gps"].ContainsKey("LastLongitude") && (json["Gps"]["LastLongitude"].IsDouble || json["Gps"]["LastLongitude"].IsInt)
-      && json["Gps"].ContainsKey("LastGPSPos") && json["Gps"]["LastGPSPos"].IsString
-      && json["Gps"].ContainsKey("Hdop") && (json["Gps"]["Hdop"].IsDouble || json["Gps"]["Hdop"].IsInt)
-      && json["Gps"].ContainsKey("Fix") && json["Gps"]["Fix"].IsBoolean
-      && json["Gps"].ContainsKey("Height") && (json["Gps"]["Height"].IsDouble || json["Gps"]["Height"].IsInt)
-      && json.ContainsKey("Name") && json["Name"].IsString &&
-      json.ContainsKey("Calculatedcrc") && json["Calculatedcrc"].IsInt;
   }
-}
\ No newline at end of file
+}
diff --git a/Lora-Map/Model/PositionItem.cs b/Lora-Map/Model/PositionItem.cs
index 682708a..db742f0 100644
--- a/Lora-Map/Model/PositionItem.cs
+++ b/Lora-Map/Model/PositionItem.cs
@@ -3,7 +3,7 @@ using System.Globalization;
 using LitJson;
 
 namespace Fraunhofer.Fit.IoT.LoraMap.Model {
-  class PositionItem {
+  public class PositionItem {
     private Double _lastLat = 0;
     private Double _lastLon = 0;
 
@@ -30,7 +30,7 @@ namespace Fraunhofer.Fit.IoT.LoraMap.Model {
     }
 
     public void UpdateMarker(JsonData marker, String id) {
-      if(marker.ContainsKey(id)) {
+      if(marker != null && marker.ContainsKey(id)) {
         this.Name = marker[id].ContainsKey("name") && marker[id]["name"].IsString ? (String)marker[id]["name"] : id;
         this.Icon = marker[id].ContainsKey("marker.svg") && marker[id]["marker.svg"].IsObject ? Marker.ParseMarkerConfig(marker[id]["marker.svg"], this.Name) : marker[id].ContainsKey("icon") && marker[id]["icon"].IsString ? (String)marker[id]["icon"] : null;
         this.Group = marker[id].ContainsKey("Group") && marker[id]["Group"].IsString ? (String)marker[id]["Group"] : "no";
@@ -51,7 +51,7 @@ namespace Fraunhofer.Fit.IoT.LoraMap.Model {
 
     public static String GetId(JsonData json) => (String)json["Name"];
 
-    public void Update(JsonData json) {
+    public virtual void Update(JsonData json) {
       this.Rssi = json.ContainsKey("Rssi") && (json["Rssi"].IsDouble || json["Rssi"].IsInt) && Double.TryParse(json["Rssi"].ToString(), out Double rssi) ? rssi : 0;
       this.Snr = json.ContainsKey("Snr") && (json["Snr"].IsDouble || json["Snr"].IsInt) && Double.TryParse(json["Snr"].ToString(), out Double snr) ? snr : 0;
       this.Lorarecievedtime = json.ContainsKey("Receivedtime") && json["Receivedtime"].IsString && DateTime.TryParse((String)json["Receivedtime"], DateTimeFormatInfo.InvariantInfo, DateTimeStyles.AssumeUniversal, out DateTime updatetime) ? updatetime.ToUniversalTime() : DateTime.UtcNow;
diff --git a/Lora-Map/Server.cs b/Lora-Map/Server.cs
index 0383c3c..3050714 100644
--- a/Lora-Map/Server.cs
+++ b/Lora-Map/Server.cs
@@ -71,7 +71,7 @@ namespace Fraunhofer.Fit.IoT.LoraMap {
     protected override void Backend_MessageIncomming(Object sender, BackendEvent mqtt) {
       try {
         JsonData d = JsonMapper.ToObject(mqtt.Message);
-        if(PositionItem.CheckJson(d) && ((String)mqtt.From).Contains("lora/data")) {
+        if(((String)mqtt.From).Contains("lora/data") && PositionItem.CheckJson(d)) {
           String name = PositionItem.GetId(d);
           lock(this.lockData) {
             if(this.positions.ContainsKey(name)) {
@@ -81,8 +81,8 @@ namespace Fraunhofer.Fit.IoT.LoraMap {
             }
           }
           Console.WriteLine("Koordinate erhalten!");
-        } else if(AlarmItem.CheckJson(d) && ((String)mqtt.From).Contains("lora/panic")) {
-          String name = AlarmItem.GetId(d);
+        } else if(((String)mqtt.From).Contains("lora/panic") && PositionItem.CheckJson(d)) {
+          String name = PositionItem.GetId(d);
           lock(this.lockPanic) {
             if(this.alarms.ContainsKey(name)) {
               this.alarms[name].Update(d);
@@ -98,7 +98,7 @@ namespace Fraunhofer.Fit.IoT.LoraMap {
             }
           }
           Console.WriteLine("PANIC erhalten!");
-        } else if(Camera.CheckJson(d) && ((String)mqtt.From).Contains("camera/count")) {
+        } else if(((String)mqtt.From).Contains("camera/count") && Camera.CheckJson(d)) {
           String cameraid = Camera.GetId(d);
           lock(this.lockCount) {
             if(this.counter.ContainsKey(cameraid)) {