diff --git a/ADIS_Csharp/RobotLib/IndependentRobotConfigurator.cs b/ADIS_Csharp/RobotLib/IndependentRobotConfigurator.cs
index e791c88..a70807a 100644
--- a/ADIS_Csharp/RobotLib/IndependentRobotConfigurator.cs
+++ b/ADIS_Csharp/RobotLib/IndependentRobotConfigurator.cs
@@ -21,7 +21,7 @@ namespace RobotLib
            // test if IP valid
             if (IPAddress.TryParse(brokerIp, out _))
             {
-                SendMessageUdp(hostnameRobot, udpPortRobot, $"mqtt setIp {brokerIp}");
+                SendMessageUdp(hostnameRobot, udpPortRobot, $"@esp:mqtt setIp {brokerIp}!");
             }
             else
             {
@@ -39,7 +39,7 @@ namespace RobotLib
             // test if mode is valid
             if (mode == "stationary" || mode == "s" || mode == "mobile" || mode == "m")
             {
-                SendMessageUdp(hostnameRobot, udpPortRobot, $"challenge setMode {mode}");
+                SendMessageUdp(hostnameRobot, udpPortRobot, $"@esp:challenge setMode {mode}!");
             }
             else
             {
@@ -54,14 +54,22 @@ namespace RobotLib
         /// <param name="hostnameRobot">hostname or IP address of the robot</param>
         public static void RebootEsp32(string hostnameRobot)
         {
-            SendMessageUdp(hostnameRobot, udpPortRobot, $"challenge reboot");
+            SendMessageUdp(hostnameRobot, udpPortRobot, $"@esp:challenge reboot!");
         }
 
 
         private static void SendMessageUdp(string hostname, int port, string message)
         {
             var udpClient = new UdpClient();
-            udpClient.Connect(hostname, port);
+            try
+            {
+                udpClient.Connect(hostname, port);
+            }
+            catch (System.Exception ex)
+            {
+                log.Error($"Failed to send UDP message: {ex.Message}");
+                return;
+            }
 
             byte[] data = Encoding.ASCII.GetBytes(message);
             udpClient.Send(data, data.Length);