diff --git a/APBUARTPLUGIN/uartpollingthread.cpp b/APBUARTPLUGIN/uartpollingthread.cpp
--- a/APBUARTPLUGIN/uartpollingthread.cpp
+++ b/APBUARTPLUGIN/uartpollingthread.cpp
@@ -90,7 +90,7 @@ void UARTPollingThread::run()
                 SocExplorerEngine::message(this->plugin,QString("Received one char from APBUART"),3);
                 emit this->apbUartTextReceived(QString(ch[0]));
             }
-            msleep(1);
+            msleep(10);
         }
     }
 }
diff --git a/ahbuartplugin/ahbuartplugin.cpp b/ahbuartplugin/ahbuartplugin.cpp
--- a/ahbuartplugin/ahbuartplugin.cpp
+++ b/ahbuartplugin/ahbuartplugin.cpp
@@ -95,6 +95,7 @@ bool ahbuartplugin::checkConnection()
     int read = 0;
     timeout.start();
     SocExplorerEngine::message(this,"Check connection",2);
+    QMutexLocker lock(portMutex);
     while(writen!=5)
     {
         writen+=rs232write(this->port,test+writen,5-writen);
@@ -131,6 +132,7 @@ void ahbuartplugin::connectPort(QString 
     QTime timeout;
     SocExplorerEngine::message(this,"Try to connect to port "+PortName,2);
     timeout.start();
+    QMutexLocker lock(portMutex);
     if(this->port==(rs232port_t)NULL)
     {
         SocExplorerEngine::message(this,"Open port "+PortName,2);
@@ -232,8 +234,9 @@ unsigned int ahbuartplugin::Read(unsigne
     SocExplorerEngine::message(this,QString("Read ")+ QString::number(count) + QString(" words @0x")+ QString::number(address,16),2);
     if((this->port!= badPortValue)||(this->port!=(rs232port_t)NULL))
     {
-        if(!this->portMutex->tryLock())
-            return 0;
+        QMutexLocker lock(portMutex);
+//        if(!this->portMutex->tryLock())
+//            return 0;
         if(!this->checkConnection())
         {
             this->Connected = false;
@@ -304,7 +307,7 @@ unsigned int ahbuartplugin::Read(unsigne
         if(cnt>128)
             SocExplorerEngine::deleteProgressBar(progress);
         free(result);
-        this->portMutex->unlock();
+//        this->portMutex->unlock();
     }
     return read/4;
 }
@@ -318,8 +321,9 @@ unsigned int ahbuartplugin::Write(unsign
     SocExplorerEngine::message(this,QString("Write ")+ QString::number(count) + QString(" words @0x")+ QString::number(address,16),2);
     if((this->port!= badPortValue)||(this->port!=(rs232port_t)NULL))
     {
-        if(!this->portMutex->tryLock())
-            return 0;
+        QMutexLocker lock(portMutex);
+//        if(!this->portMutex->tryLock())
+//            return 0;
         if(!this->checkConnection())
         {
             emit this->activateSig(false);
@@ -384,7 +388,7 @@ unsigned int ahbuartplugin::Write(unsign
             SocExplorerEngine::deleteProgressBar(progress);
         }
         free(CMD);
-        this->portMutex->unlock();
+//        this->portMutex->unlock();
         return writen;
     }
     return 0;