diff --git a/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryGenericDevice.java b/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryGenericDevice.java
index 95d2c6a..2e9a977 100644
--- a/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryGenericDevice.java
+++ b/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryGenericDevice.java
@@ -20,6 +20,8 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
@@ -107,6 +109,8 @@ public class ProcessDataResult {
 
     private final AtomicBoolean reconnecting = new AtomicBoolean(false);
 
+    protected final Lock processLock = new ReentrantLock();
+
     AtomicLong readed = new AtomicLong(0);
     AtomicLong readedBytes = new AtomicLong(0);
     long metricsStart = 0;
@@ -153,11 +157,14 @@ public void dispose() {
             return;
         }
         disposed = true;
+
+        logger.debug("{} - Disposing...", toString());
         close();
 
         if (periodicJob != null) {
             periodicJob.cancel(true);
             periodicJob = null;
+            logger.debug("{} - Periodic job cancelled", toString());
         }
     }
 
@@ -298,6 +305,33 @@ protected void offerNewDataCheckPriority(int deviceAddress) throws InterruptedEx
     protected void offerNewDataCheckPriority(int deviceAddress, boolean forceAllDataAsNew) throws InterruptedException {
         SimpleBinaryItemData data = SimpleBinaryProtocol.compileNewDataFrame(deviceAddress, forceAllDataAsNew);
 
+        // is already there?
+        if (!commandQueue.isEmpty()) {
+            var first = commandQueue.getFirst().getData();
+            if (first.length == 4) {
+                boolean match = true;
+                for (int i = 0; i < 4; i++) {
+                    if (first[i] != data.getData()[i]) {
+                        match = false;
+                        break;
+                    }
+                }
+                if (match) {
+                    return;
+                }
+            }
+            // is there "check" without force
+            for (SimpleBinaryItemData qitem : commandQueue) {
+                if (qitem.getData().length != 4) {
+                    continue;
+                }
+                // remove it if match
+                if (qitem.getData()[0] == data.getData()[0] && qitem.getData()[1] == (byte) 0xD0) {
+                    commandQueue.remove(qitem);
+                    break;
+                }
+            }
+        }
         commandQueue.addFirst(data);
     }
 
@@ -364,7 +398,7 @@ protected boolean matchInQueueDataPacket(SimpleBinaryItemData item) {
 
         for (SimpleBinaryItemData qitem : commandQueue) {
             if (qitem.getData().length != item.getData().length) {
-                break;
+                continue;
             }
 
             for (int i = 0; i < qitem.getData().length; i++) {
@@ -393,7 +427,6 @@ protected boolean matchInQueueTarget(SimpleBinaryItemData item, Boolean remove)
         }
 
         for (SimpleBinaryItemData qitem : commandQueue) {
-
             if (qitem.deviceId == item.deviceId && qitem.itemAddress == item.itemAddress) {
                 if (remove) {
                     commandQueue.remove(qitem);
@@ -418,30 +451,20 @@ protected void processCommandQueue(int thisDeviceOnly) {
             logger.debug("{} - Processing commandQueue - length {}. Only device {}. Thread={}", toString(),
                     commandQueue.size(), thisDeviceOnly, Thread.currentThread().getId());
         }
-
-        // no reply expected
-        if (!canSend(thisDeviceOnly)) {
+        // queue is empty -> exit
+        if (commandQueue.isEmpty()) {
+            return;
+        }
+        // no reply expected - no command processed
+        if (!canSend(thisDeviceOnly) || !processLock.tryLock()) {
             if (logger.isDebugEnabled()) {
                 logger.debug("{} - Processing commandQueue - waiting", this.toString());
             }
             return;
         }
 
-        /*
-         * if (!lock.tryLock()) {
-         * if (logger.isDebugEnabled()) {
-         * logger.debug("{} - CommandQueue locked. Leaving processCommandQueue.", toString());
-         * }
-         * return;
-         * }
-         */
-        SimpleBinaryItemData dataToSend = null;
-
         try {
-            // queue is empty -> exit
-            if (commandQueue.isEmpty()) {
-                return;
-            }
+            SimpleBinaryItemData dataToSend = null;
 
             for (SimpleBinaryItemData i : commandQueue) {
                 if (i.deviceId == thisDeviceOnly) {
@@ -450,14 +473,13 @@ protected void processCommandQueue(int thisDeviceOnly) {
                     break;
                 }
             }
+            if (dataToSend != null) {
+                sendDataOut(dataToSend);
+            }
         } catch (Exception e) {
             logger.error("{} - Processing commandQueue(int) - error: {}", this.toString(), e.getMessage());
         } finally {
-            // lock.unlock();
-        }
-
-        if (dataToSend != null) {
-            sendDataOut(dataToSend);
+            processLock.unlock();
         }
     }
 
@@ -474,30 +496,20 @@ protected void processCommandQueue() {
             logger.debug("{} - Processing commandQueue - length {}. Thread={}", toString(), commandQueue.size(),
                     Thread.currentThread().getId());
         }
-
-        // no reply expected
-        if (!canSend()) {
+        // queue is empty -> exit
+        if (commandQueue.isEmpty()) {
+            return;
+        }
+        // no reply expected or already in process
+        if (!canSend() || !processLock.tryLock()) {
             if (logger.isDebugEnabled()) {
                 logger.debug("{} - Processing commandQueue - waiting", this.toString());
             }
             return;
         }
 
-        /*
-         * if (!lock.tryLock()) {
-         * if (logger.isDebugEnabled()) {
-         * logger.debug("{} - CommandQueue locked. Leaving processCommandQueue.", toString());
-         * }
-         * return;
-         * }
-         */
-        SimpleBinaryItemData dataToSend = null;
-
         try {
-            // queue is empty -> exit
-            if (commandQueue.isEmpty()) {
-                return;
-            }
+            SimpleBinaryItemData dataToSend = null;
 
             // check first command in queue
             SimpleBinaryItemData firstdata = commandQueue.pollFirst();
@@ -623,6 +635,10 @@ protected void processCommandQueue() {
                     return;
                 }
             }
+
+            if (dataToSend != null) {
+                sendDataOut(dataToSend);
+            }
         } catch (Exception e) {
             logger.error("{} - Processing commandQueue - error: {}", this.toString(), e.toString());
             StringWriter sw = new StringWriter();
@@ -630,11 +646,7 @@ protected void processCommandQueue() {
             e.printStackTrace(pw);
             logger.error("Stacktrace: {}", sw.toString());
         } finally {
-            // lock.unlock();
-        }
-
-        if (dataToSend != null) {
-            sendDataOut(dataToSend);
+            processLock.unlock();
         }
     }
 
diff --git a/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryUART.java b/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryUART.java
index be115da..e42a6ce 100644
--- a/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryUART.java
+++ b/org.openhab.binding.simplebinary/src/main/java/org/openhab/binding/simplebinary/internal/core/SimpleBinaryUART.java
@@ -288,7 +288,11 @@ public void close(String reason) {
      */
     @Override
     protected boolean canSend() {
-        return !waitingForAnswer.get();
+        if (waitingForAnswer.get()) {
+            return false;
+        }
+
+        return super.canSend();
     }
 
     /*