diff --git a/02_Windows_App/Perun_v1/01_Classes/Globals.cs b/02_Windows_App/Perun_v1/01_Classes/Globals.cs
index 27b4bac..efa6ebe 100644
--- a/02_Windows_App/Perun_v1/01_Classes/Globals.cs
+++ b/02_Windows_App/Perun_v1/01_Classes/Globals.cs
@@ -7,7 +7,7 @@ internal class Globals
     public static string[] arrLogHistory = new string[10];      // Log history for GUI
     public static bool bLogHistoryUpdate = true;               // Mark if log control require update
     public static string strPerunTitleText = "";
-
+    public static int intInstanceId = 0;                // Instance ID
     public static bool bStatusIconsForce = true;        // Force icons reload
     public static bool bdcConnection = false;           // Historic db connection status
     public static bool btcpcServer = false;             // Historic tcp connection status
diff --git a/02_Windows_App/Perun_v1/01_Classes/LogController.cs b/02_Windows_App/Perun_v1/01_Classes/LogController.cs
new file mode 100644
index 0000000..d1ba151
--- /dev/null
+++ b/02_Windows_App/Perun_v1/01_Classes/LogController.cs
@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+class LogController
+{
+    // TBD - via https://stackoverflow.com/questions/20185015/how-to-write-log-file-in-c
+    public static void WriteLog(string strLog)
+    {
+        StreamWriter log;
+        FileStream fileStream = null;
+        DirectoryInfo logDirInfo = null;
+        FileInfo logFileInfo;
+
+        string logFilePath = Path.Combine(Environment.ExpandEnvironmentVariables("%userprofile%"), "Documents") + "\\Perun\\";
+        logFilePath = logFilePath + "Perun_Log_" + System.DateTime.Today.ToString("yyyyddMM") + "." + "txt";
+        logFileInfo = new FileInfo(logFilePath);
+        logDirInfo = new DirectoryInfo(logFileInfo.DirectoryName);
+        if (!logDirInfo.Exists) logDirInfo.Create();
+        if (!logFileInfo.Exists)
+        {
+            fileStream = logFileInfo.Create();
+        }
+        else
+        {
+            fileStream = new FileStream(logFilePath, FileMode.Append);
+        }
+        log = new StreamWriter(fileStream);
+        log.WriteLine(strLog);
+        log.Close();
+    }
+}
diff --git a/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs b/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs
index faafdd3..c6c1f0d 100644
--- a/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs
+++ b/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs
@@ -12,7 +12,8 @@ internal class PerunHelper
             arrLogHistory[i] = arrLogHistory[i + 1]; // Shift one down
         }
 
-        arrLogHistory[arrLogHistory.Length - 1] = DateTime.Now.ToString("HH:mm:ss") + " > " + strEntryToAdd; // Add entry at the last position
+        arrLogHistory[arrLogHistory.Length - 1] = DateTime.Now.ToString("yyyy-dd-MM HH:mm:ss") + " > " + strEntryToAdd; // Add entry at the last position
+        LogController.WriteLog(arrLogHistory[arrLogHistory.Length - 1]);
         Globals.bLogHistoryUpdate = true;
     }
     public static string GetAppVersion(string strBeginning)
diff --git a/02_Windows_App/Perun_v1/01_Classes/TCPController.cs b/02_Windows_App/Perun_v1/01_Classes/TCPController.cs
index 7c682a8..49c11ca 100644
--- a/02_Windows_App/Perun_v1/01_Classes/TCPController.cs
+++ b/02_Windows_App/Perun_v1/01_Classes/TCPController.cs
@@ -16,7 +16,7 @@ public class TCPController
     public string[] arrSendBuffer;   // Mysql send buffer
     public Thread thrTCPListener;    // Seperate thread for TCP
     public bool bStatus;             // TCP connecion status
-
+    
     public void Create(int par_intListenPort, ref string[] par_arrLogHistory, ref string[] par_arrSendBuffer)
     {
         // Create class
@@ -92,7 +92,7 @@ public class TCPController
                             dynamic dynamicRawTCPFrame = JsonConvert.DeserializeObject(strReceivedData); // Deserialize received frame
                             string strRawTCPFrameType = dynamicRawTCPFrame.type;
 
-                            PerunHelper.LogHistoryAdd(ref arrLogHistory, "TCP packet received, type: " + strRawTCPFrameType);
+                            PerunHelper.LogHistoryAdd(ref arrLogHistory, "#" + Globals.intInstanceId + "> TCP packet received, type: " + strRawTCPFrameType);
 
                             // Add to mySQL send buffer (find first empty slot)
                             for (int i = 0; i < arrSendBuffer.Length - 1; i++)
diff --git a/02_Windows_App/Perun_v1/02_Forms/form_Main.cs b/02_Windows_App/Perun_v1/02_Forms/form_Main.cs
index cbcd6ea..5cbb18a 100644
--- a/02_Windows_App/Perun_v1/02_Forms/form_Main.cs
+++ b/02_Windows_App/Perun_v1/02_Forms/form_Main.cs
@@ -153,8 +153,12 @@ namespace Perun_v1
         // ################################ User input ################################
         private void con_Button_Listen_ON_Click(object sender, EventArgs e)
         {
+            // Set globals
+            Globals.intInstanceId= Int32.Parse(con_txt_dcs_instance.Text);
+            Globals.bStatusIconsForce = true;
+
             // Start listening
-            PerunHelper.LogHistoryAdd(ref Globals.arrLogHistory, "Opening connections");
+            PerunHelper.LogHistoryAdd(ref Globals.arrLogHistory, "#" + Globals.intInstanceId + " > " + "Opening connections");
             tcpcServer.Create(Int32.Parse(con_txt_dcs_server_port.Text), ref Globals.arrLogHistory, ref arrSendBuffer);
             tcpcServer.thrTCPListener = new Thread(tcpcServer.StartListen);
             tcpcServer.thrTCPListener.Start();
@@ -166,9 +170,6 @@ namespace Perun_v1
             // Prepare connection string
             dcConnection.strMySQLConnectionString = "server=" + con_txt_mysql_server.Text + ";user=" + con_txt_mysql_username.Text + ";database=" + con_txt_mysql_database.Text + ";port=" + con_txt_mysql_port.Text + ";password=" + con_txt_mysql_password.Text;
 
-            // Force icons update
-            Globals.bStatusIconsForce = true;
-
             // Start timmers
             tim_200ms.Enabled = true;
             tim_1000ms.Enabled = true;
@@ -186,7 +187,7 @@ namespace Perun_v1
             // Stop listening
 
             // Display information
-            PerunHelper.LogHistoryAdd(ref Globals.arrLogHistory, "Closing connections");
+            PerunHelper.LogHistoryAdd(ref Globals.arrLogHistory, "#" + Globals.intInstanceId +" > " + "Closing connections");
             con_Button_Listen_OFF.Enabled = false;
             timer1_Tick(null, null);
             this.Refresh();
@@ -219,12 +220,15 @@ namespace Perun_v1
             tim_200ms.Enabled = false;
 
             // Display information about closed connections
-            PerunHelper.LogHistoryAdd(ref Globals.arrLogHistory, "Connections closed");
+            PerunHelper.LogHistoryAdd(ref Globals.arrLogHistory, "#" + Globals.intInstanceId +" > " + "Connections closed");
             timer1_Tick(null, null);
 
             // Set title bar
             this.Text = Globals.strPerunTitleText;
 
+            // Set globals
+            Globals.intInstanceId = 0;
+
             // Set helpers for updates
             Globals.bLogHistoryUpdate = false;
             Globals.bdcConnection = false;
diff --git a/02_Windows_App/Perun_v1/Perun_v1.csproj b/02_Windows_App/Perun_v1/Perun_v1.csproj
index 83f3640..2c076d4 100644
--- a/02_Windows_App/Perun_v1/Perun_v1.csproj
+++ b/02_Windows_App/Perun_v1/Perun_v1.csproj
@@ -124,6 +124,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="01_Classes\LogController.cs" />
     <Compile Include="01_Classes\TCPController.cs" />
     <Compile Include="01_Classes\Globals.cs" />
     <Compile Include="01_Classes\DatabaseController.cs" />