diff --git a/02_Windows_App/Perun_v1/01_Classes/Globals.cs b/02_Windows_App/Perun_v1/01_Classes/Globals.cs
index 0e65acb..d1dba87 100644
--- a/02_Windows_App/Perun_v1/01_Classes/Globals.cs
+++ b/02_Windows_App/Perun_v1/01_Classes/Globals.cs
@@ -5,6 +5,8 @@ internal class Globals
 {
     public static string strPerunVersion = "DEBUG";             // Helper for pulling version definition
     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 = "";
+   
 }
 
diff --git a/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs b/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs
index a8b8395..faafdd3 100644
--- a/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs
+++ b/02_Windows_App/Perun_v1/01_Classes/PerunHelper.cs
@@ -13,6 +13,7 @@ internal class PerunHelper
         }
 
         arrLogHistory[arrLogHistory.Length - 1] = DateTime.Now.ToString("HH:mm:ss") + " > " + strEntryToAdd; // Add entry at the last position
+        Globals.bLogHistoryUpdate = true;
     }
     public static string GetAppVersion(string strBeginning)
     {
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 3f9ecbb..f7e0d5a 100644
--- a/02_Windows_App/Perun_v1/02_Forms/form_Main.cs
+++ b/02_Windows_App/Perun_v1/02_Forms/form_Main.cs
@@ -201,7 +201,7 @@ namespace Perun_v1
 
             while (tcpcServer.thrTCPListener.IsAlive)
             {
-                Thread.Sleep(100); //ms
+                Thread.Sleep(10); //ms
             }
             form_Main_EnableControls(); // Enable controls
 
@@ -337,13 +337,20 @@ namespace Perun_v1
         {
             // Main timer to sync GUI with background tasks and flush buffers
             // Refresh Log Window
-            con_List_Received.Items.Clear();
-            foreach (string i in Globals.arrLogHistory)
+            if (Globals.bLogHistoryUpdate)
             {
-                if (i != null)
+                con_List_Received.Items.Clear();
+                foreach (string i in Globals.arrLogHistory)
                 {
-                    con_List_Received.Items.Add(i);
+                    if (i != null)
+                    {
+                        con_List_Received.Items.Add(i);
+                    }
                 }
+                Globals.bLogHistoryUpdate = false;
+            } else
+            {
+                // Do nothing , control does not require update
             }
         }