diff --git a/src/ATBAPP/DeviceControllerDiag.cpp b/src/ATBAPP/DeviceControllerDiag.cpp
index d622d85..0797ec0 100644
--- a/src/ATBAPP/DeviceControllerDiag.cpp
+++ b/src/ATBAPP/DeviceControllerDiag.cpp
@@ -54,7 +54,7 @@ void DeviceControllerDiag::private_startDiag()
     // check for DiagRequestTimeoutTimerTimeout:
     if (this->flagInterruptDiag) {
         qCritical() << "DeviceControllerDiag::private_startDiag() interrupted!";
-        this->private_finishedDiag(DeviceController::State::E255);
+        this->private_sendDiagEvent(DeviceController::State::E255);
         return;
     }
 
@@ -86,7 +86,7 @@ void DeviceControllerDiag::sys_superviseSystem()
     // check for DiagRequestTimeoutTimerTimeout:
     if (this->flagInterruptDiag) {
         qCritical() << "DeviceControllerDiag::sys_superviseSystem() interrupted!";
-        this->private_finishedDiag(DeviceController::State::E255);
+        this->private_sendDiagEvent(DeviceController::State::E255);
         return;
     }
 
@@ -94,7 +94,7 @@ void DeviceControllerDiag::sys_superviseSystem()
     {
         // es gibt keinerlei gültige Daten vom DC
         qCritical() << "DeviceControllerDiag::sys_superviseSystem() no valid data!";
-        this->private_finishedDiag(DeviceController::State::E254);
+        this->private_sendDiagEvent(DeviceController::State::E254);
         return;
     }
 
@@ -121,29 +121,26 @@ void DeviceControllerDiag::sys_superviseSystem()
     if (dynMaCond.lowerDoor || dynMaCond.upperDoor) {
         // Service or battery door is open, goto INTRUSION MODE
         qCritical() << "DeviceControllerDiag::sys_superviseSystem() Service or battery door is open, goto INTRUSION MODE";
-        this->private_finishedDiag(DeviceController::State::E253);
+        this->private_sendDiagEvent(DeviceController::State::E253);
         return;
     }
     if (dynMaCond.middleDoor) {
         // vault door is open, goto INTRUSION MODE
         qCritical() << "DeviceControllerDiag::sys_superviseSystem() vault door is open, goto INTRUSION MODE";
-        this->private_finishedDiag(DeviceController::State::E252);
+        this->private_sendDiagEvent(DeviceController::State::E252);
         return;
     }
 
     qCritical() << "      --> call  sub_componentAssessment()";
 
-    DeviceController::State proposedError = sub_componentAssessment();
-
-    this->private_finishedDiag(proposedError);
+    sub_componentAssessment();
 }
 
 
 
-DeviceController::State DeviceControllerDiag::sub_componentAssessment()
+void DeviceControllerDiag::sub_componentAssessment()
 {
-    // this function decides if vending mode is possible, independant from door
-    // return >0 in case of error
+    bool flag_sendOperate = true;
 
     struct T_moduleCondition modCond;
     hw->sys_getDeviceConditions(&modCond);
@@ -160,72 +157,90 @@ DeviceController::State DeviceControllerDiag::sub_componentAssessment()
     emit newVoltage(voltage);
 
 
+    // check for alarm:
+
+    if (dynMaCond.onAlarm>0) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::A000);
+    }
 
     // check for invalid states:
 
-    if (modCond.rtc>=200)
-        return DeviceController::State::E002;
-    if (modCond.printer==200 || modCond.printer==201)   // 200: not connected  201: printer-HW-error  202: no paper
-        return DeviceController::State::E020;
-    if (modCond.printer==202)
-        return DeviceController::State::E018;
+    if (modCond.rtc>=200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E002);
+    }
+    if (modCond.printer==200 || modCond.printer==201) {   // 200: not connected  201: printer-HW-error  202: no paper
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E020);
+    }
+    if (modCond.printer==202) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E018);
+    }
 
-    if (modCond.coinBlocker>=200)
-        return DeviceController::State::E025;
-    if (modCond.mdbBus>=200)
-        return DeviceController::State::E034;
-    if (modCond.intEe>=200)
-        return DeviceController::State::E011;
+    if (modCond.coinBlocker>=200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E025);
+    }
+    if (modCond.mdbBus>=200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E034);
+    }
+    if (modCond.intEe>=200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E011);
+    }
 
     // 2023-07-26: workaround for 00281/Szeged --------------------------------------------------------------
     // because we need certain errors and we do get for 'kindOfCoinChecker' -> 16 !
     qCritical() << "-----------diag: kindOfCoinChecker = " << devPara.kindOfCoinChecker;
     qCritical() << "                  modCond.coinSafe = " << modCond.coinSafe;
     if (devPara.kindOfCoinChecker > 0) {
-        if (modCond.coinSafe==201) // full
-        {
-            return DeviceController::State::E007;
+        if (modCond.coinSafe==201) { // full
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E007);
         }
-        if (modCond.coinSafe==200)           // 200: kasse fehlt 201: voll  100:fast voll  1:ok
-        {
-            return DeviceController::State::E009;
+        if (modCond.coinSafe==200)  {         // 200: kasse fehlt 201: voll  100:fast voll  1:ok
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E009);
         }
-        if (modCond.coinEscrow>=200)
-        {
-            return DeviceController::State::E010;
+        if (modCond.coinEscrow>=200) {
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E010);
         }
     }
     // -----------------------------------------------------------------------------------------------
 
     if (devPara.kindOfCoinChecker==1 || devPara.kindOfCoinChecker==2)  // 0: without  1=EMP820   2=EMP900    3=currenza c²	(MW)
     {
-        if (modCond.coinEscrow>=200)
-        {
-            return DeviceController::State::E010;
+        if (modCond.coinEscrow>=200) {
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E010);
         }
-        if (modCond.coinSafe==201) // full
-        {
-            return DeviceController::State::E007;
+        if (modCond.coinSafe==201)  { // full
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E007);
         }
-        if (modCond.coinSafe==200)           // 200: kasse fehlt 201: voll  100:fast voll  1:ok
-        {
-            return DeviceController::State::E009;
+        if (modCond.coinSafe==200) {          // 200: kasse fehlt 201: voll  100:fast voll  1:ok
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E009);
         }
     } else
     if (devPara.kindOfCoinChecker==3)
     {
-        if (modCond.changer>=200)
-        {
+        if (modCond.changer>=200) {
             // Fehler Münzver.
-            return DeviceController::State::E026;
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E026);
         }
-        if (modCond.coinSafe==201) // full
-        {
-            return DeviceController::State::E007;
+        if (modCond.coinSafe==201) { // full
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E007);
         }
-        if (modCond.coinSafe == 200)           // 200: kasse fehlt 201: voll  100:fast voll  1:ok
-        {
-            return DeviceController::State::E009;
+        if (modCond.coinSafe == 200)  {          // 200: kasse fehlt 201: voll  100:fast voll  1:ok
+            flag_sendOperate = false;
+            this->private_sendDiagEvent(DeviceController::State::E009);
         }
     }
 
@@ -243,44 +258,56 @@ DeviceController::State DeviceControllerDiag::sub_componentAssessment()
     }
     */
 
-    if (dynMaCond.onAlarm>0)
-        return DeviceController::State::A000;
+    if (dynMaCond.modeAbrech>0) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E011);
+    }
 
-    if (dynMaCond.modeAbrech>0)
-        return DeviceController::State::E011;
+    if (dynMaCond.nowCardTest>0) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E072);
+    }
 
-    if (dynMaCond.nowCardTest>0)
-        return DeviceController::State::E072;
+    if (dynMaCond.startupTestIsRunning>0) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E073);
+    }
 
-    if (dynMaCond.startupTestIsRunning>0)
-        return DeviceController::State::E073;
-
-    if (modCond.voltage>=200)
-        return DeviceController::State::E003;
-    if (modCond.temper>=200)
-        return DeviceController::State::E004;
+    if (modCond.voltage>=200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E003);
+    }
+    if (modCond.temper>=200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::E004);
+    }
 
     // check for warnings
-    if (modCond.printer>=100 && modCond.printer<200)
-        return DeviceController::State::W001;
-    if (modCond.coinSafe>=100 && modCond.coinSafe<200)
-        return DeviceController::State::W002;
-    if (modCond.voltage>=100 && modCond.voltage<200)
-        return DeviceController::State::W003;
-    if (modCond.temper>=100 && modCond.temper<200)
-        return DeviceController::State::W004;
+    if (modCond.printer>=100 && modCond.printer<200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::W001);
+    }
+    if (modCond.coinSafe>=100 && modCond.coinSafe<200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::W002);
+    }
+    if (modCond.voltage>=100 && modCond.voltage<200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::W003);
+    }
+    if (modCond.temper>=100 && modCond.temper<200) {
+        flag_sendOperate = false;
+        this->private_sendDiagEvent(DeviceController::State::W004);
+    }
 
-    return DeviceController::State::O000;
+    if (flag_sendOperate) {
+        this->private_sendDiagEvent(DeviceController::State::O000);
+    }
 }
 
 
-DeviceController::State DeviceControllerDiag::sys_getSystemErrors()
-{
-    return this->sub_componentAssessment();
-}
-
 /**
- * @brief DeviceControllerDiag::private_finishedDiag
+ * @brief DeviceControllerDiag::private_sendDiagEvent
  * @param result - result value from 'sub_componentAssessment()',
  *               - 0x00 everything is fine
  *               - 0xFF on timer interrupt
@@ -288,13 +315,13 @@ DeviceController::State DeviceControllerDiag::sys_getSystemErrors()
  *               - 0xFD Service or battery door is open
  *               - 0xFE vault door is open
  */
-void DeviceControllerDiag::private_finishedDiag(DeviceController::State result)
+void DeviceControllerDiag::private_sendDiagEvent(DeviceController::State result)
 {
     this->diagRequestTimeoutTimer->stop();
     this->isRequestRunning  = false;
     this->flagInterruptDiag = false;
 
-    qCritical() << "DeviceControllerDiag::private_finishedDiag() result: " << result;
+    qCritical() << "DeviceControllerDiag::private_sendDiagEvent() result: " << result;
 
 
     if (this->eventReceiver == nullptr) {
@@ -302,6 +329,15 @@ void DeviceControllerDiag::private_finishedDiag(DeviceController::State result)
         return;
     }
 
+    if (machineEventSet.contains(result)) {
+        // do not send already sent events
+        qCritical() << "       ... is in machineEventList";
+        return;
+    }
+    else {
+        machineEventSet.insert(result);
+    }
+
 
     QString eventId = QUuid::createUuid().toString(QUuid::WithoutBraces).mid(0, 8);
 
@@ -380,14 +416,14 @@ void DeviceControllerDiag::private_finishedDiag(DeviceController::State result)
         parameter  = "startup-test is running";
         break;
 
-    case DeviceController::State::E252:   // oper door / lower door open
-        eventClass = EVENT_CLASS::STATE;
-        parameter  = "oper door / lower door open";
-        break;
-    case DeviceController::State::E253:   // cash box door open
+    case DeviceController::State::E252:   // cash box door open
         eventClass = EVENT_CLASS::STATE;
         parameter  = "cash box door open";
         break;
+    case DeviceController::State::E253:   // service or battery door open
+        eventClass = EVENT_CLASS::STATE;
+        parameter  = "service or battery door open";
+        break;
     case DeviceController::State::E254:   // no valid data from DeviceController
         eventClass = EVENT_CLASS::STATE;
         parameter  = "no valid data from DeviceController";
@@ -399,6 +435,7 @@ void DeviceControllerDiag::private_finishedDiag(DeviceController::State result)
         return;
         break;
     case DeviceController::State::O000:   // everything is fine
+        this->machineEventSet.clear();
         eventClass = EVENT_CLASS::OPERATE;
         parameter  = "";
         qCritical() << "                ... everything fine";
diff --git a/src/ATBAPP/DeviceControllerDiag.h b/src/ATBAPP/DeviceControllerDiag.h
index 0a3e848..e3119ee 100644
--- a/src/ATBAPP/DeviceControllerDiag.h
+++ b/src/ATBAPP/DeviceControllerDiag.h
@@ -2,6 +2,7 @@
 #define DEVICECONTROLLERDIAG_H
 
 #include <QObject>
+#include <QSet>
 #include <QTimer>
 
 #include "ATBMachineEvent.h"
@@ -78,17 +79,17 @@ private:
 
     QTimer *diagRequestTimeoutTimer;
 
-    //uint8_t sub_componentAssessment();
-    DeviceController::State sub_componentAssessment();
-    DeviceController::State sys_getSystemErrors();
+    void sub_componentAssessment(); // diag exit method
 
     int lastVoltage;
 
+    QSet<DeviceController::State> machineEventSet;
+
 private slots:
     void onDiagRequestTimeoutTimerTimeout();
 
-    void private_startDiag();                                   // diag entry method
-    void private_finishedDiag(DeviceController::State result);  // diag exit method
+    void private_startDiag();                                    // diag entry method
+    void private_sendDiagEvent(DeviceController::State result);
 
     void sys_superviseSystem();