diff --git a/src/KNXLib/KnxLockManager.cs b/src/KNXLib/KnxLockManager.cs
index dfc9257..ce5ed05 100644
--- a/src/KNXLib/KnxLockManager.cs
+++ b/src/KNXLib/KnxLockManager.cs
@@ -1,86 +1,87 @@
-using System;
-using System.Threading;
-
-namespace KNXLib
-{
-    internal class KnxLockManager
-    {
-        private readonly SemaphoreSlim _sendLock = new SemaphoreSlim(0);
-        private readonly object _connectedLock = new object();
-        private bool _isConnected;
-
-        internal int IntervalMs { get; set; } = 200;
-
-        public int LockCount
-        {
-            get { return _sendLock.CurrentCount; }
-        }
-
-        public void LockConnection()
-        {
-            lock (_connectedLock)
-            {
-                if (!_isConnected)
-                    return;
-
-                SendLock();
-                _isConnected = false;
-            }
-        }
-
-        public void UnlockConnection()
-        {
-            lock (_connectedLock)
-            {
-                if (_isConnected)
-                    return;
-
-                _isConnected = true;
-                SendUnlock();
-            }
-        }
-
-        public void PerformLockedOperation(Action action)
-        {
-            // TODO: Shouldn't this check if we are connected?
-
-            try
-            {
-                SendLock();
-                action();
-            }
-            finally
-            {
-                SendUnlockPause();
-            }
-        }
-
-        private void SendLock()
-        {
-            _sendLock.Wait();
-        }
-
-        private void SendUnlock()
-        {
-            _sendLock.Release();
-        }
-
-        private void SendUnlockPause()
-        {
+using System;
+using System.Threading;
+
+namespace KNXLib
+{
+    internal class KnxLockManager
+    {
+        private readonly SemaphoreSlim _sendLock = new SemaphoreSlim(0);
+        private readonly object _connectedLock = new object();
+        private bool _isConnected;
+
+        internal int IntervalMs { get; set; } = 200;
+
+        public int LockCount
+        {
+            get { return _sendLock.CurrentCount; }
+        }
+
+        public void LockConnection()
+        {
+            lock (_connectedLock)
+            {
+                if (!_isConnected)
+                    return;
+
+                SendLock();
+                _isConnected = false;
+            }
+        }
+
+        public void UnlockConnection()
+        {
+            lock (_connectedLock)
+            {
+                if (_isConnected)
+                    return;
+
+                _isConnected = true;
+                SendUnlock();
+            }
+        }
+
+        public void PerformLockedOperation(Action action)
+        {
+            if (!_isConnected)
+                throw new InvalidOperationException("Unable to perform action: KNX is not connected.");
+
+            try
+            {
+                SendLock();
+                action();
+            }
+            finally
+            {
+                SendUnlockPause();
+            }
+        }
+
+        private void SendLock()
+        {
+            _sendLock.Wait();
+        }
+
+        private void SendUnlock()
+        {
+            _sendLock.Release();
+        }
+
+        private void SendUnlockPause()
+        {
             if (IntervalMs == 0)
             {
-                _sendLock.Release();
+                _sendLock.Release();
                 return;
-            }
-
-            var t = new Thread(SendUnlockPauseThread) { IsBackground = true };
-            t.Start();
-        }
-
-        private void SendUnlockPauseThread()
-        {
-            Thread.Sleep(IntervalMs);
-            _sendLock.Release();
-        }
-    }
+            }
+
+            var t = new Thread(SendUnlockPauseThread) { IsBackground = true };
+            t.Start();
+        }
+
+        private void SendUnlockPauseThread()
+        {
+            Thread.Sleep(IntervalMs);
+            _sendLock.Release();
+        }
+    }
 }
\ No newline at end of file