diff --git a/slsReceiverSoftware/src/ClientInterface.cpp b/slsReceiverSoftware/src/ClientInterface.cpp
index cac999d42..14fc5a4c2 100644
--- a/slsReceiverSoftware/src/ClientInterface.cpp
+++ b/slsReceiverSoftware/src/ClientInterface.cpp
@@ -1783,7 +1783,7 @@ int ClientInterface::set_receiver_roi_metadata(Interface &socket) {
 }
 
 int ClientInterface::get_bunch_size(Interface &socket) {
-    int retval = impl()->getBunchSize();
+    int retval = static_cast<int>(impl()->getBunchSize());
     LOG(logDEBUG1) << "bunch size retval:" << retval;
     return socket.sendResult(retval);
 }
@@ -1796,7 +1796,7 @@ int ClientInterface::set_bunch_size(Interface &socket) {
     verifyIdle(socket);
     LOG(logDEBUG1) << "Setting bunch size:" << value;
     try {
-        impl()->setBunchSize(value);
+        impl()->setBunchSize(static_cast<size_t>(value));
     } catch (const RuntimeError &e) {
         throw RuntimeError("Could not set rx bunch size due to fifo structure memory allocation.");
     }
diff --git a/slsReceiverSoftware/src/DataProcessor.cpp b/slsReceiverSoftware/src/DataProcessor.cpp
index e6d869bde..92430000e 100644
--- a/slsReceiverSoftware/src/DataProcessor.cpp
+++ b/slsReceiverSoftware/src/DataProcessor.cpp
@@ -60,7 +60,7 @@ void DataProcessor::SetReceiverROI(ROI roi) {
     receiverRoiEnabled_ = receiverRoi_.completeRoi() ? false : true;
 }
 
-void DataProcessor::SetBunchSize(uint32_t value) {
+void DataProcessor::SetBunchSize(size_t value) {
     fifoBunchSize = value;
 }
 
@@ -267,7 +267,8 @@ void DataProcessor::ThreadExecution() {
                    << static_cast<void *>(buffer) << std::dec;
 
     char* tempBuffer = buffer;
-    for (uint32_t iFrame = 0; iFrame != fifoBunchSize; iFrame ++) {
+    for (size_t iFrame = 0; iFrame != fifoBunchSize; iFrame ++) {
+        LOG(logDEBUG1) << "iFrame:" << iFrame;
 
         // end of acquisition (check dummy)
         auto numBytes = *reinterpret_cast<uint32_t *>(tempBuffer);
@@ -295,19 +296,26 @@ void DataProcessor::ThreadExecution() {
             memcpy(buffer + generalData_->fifoBufferHeaderSize, &completeImageToStreamBeforeCropping[0], generalData_->imageSize);
         }
         fifo_->PushAddressToStream(buffer);
+        LOG(logINFORED) << "push to stream!??";
+
     } else {
         fifo_->FreeAddress(buffer);
+        LOG(logDEBUG1) << "Pushed (free) dataprocessing bunch (EOA) " << std::hex << static_cast<void *>(buffer)  << std::dec;
     }
 }
 
 void DataProcessor::StopProcessing(char *buf) {
-    LOG(logINFORED) << "DataProcessing " << index << ": Dummy";
+    LOG(logDEBUG1) << "DataProcessing " << index << ": Dummy";
 
     // stream dummy or free
-    if (*dataStreamEnable_)
+    if (*dataStreamEnable_) {
+        LOG(logINFORED) << "push to stream!??";
         fifo_->PushAddressToStream(buf);
-    else
+    }
+    else {
         fifo_->FreeAddress(buf);
+        LOG(logDEBUG1) << "Pushed (free) stop proc dataprocessing bunch (EOA) " << std::hex << static_cast<void *>(buf)  << std::dec;
+    }
 
     CloseFiles();
     StopRunning();
diff --git a/slsReceiverSoftware/src/DataProcessor.h b/slsReceiverSoftware/src/DataProcessor.h
index 5d558072c..639cc5cfe 100644
--- a/slsReceiverSoftware/src/DataProcessor.h
+++ b/slsReceiverSoftware/src/DataProcessor.h
@@ -44,7 +44,7 @@ class DataProcessor : private virtual slsDetectorDefs, public ThreadObject {
     void SetReceiverROI(ROI roi);
     void ResetParametersforNewAcquisition();
     void SetGeneralData(GeneralData *generalData);
-    void SetBunchSize(uint32_t value);
+    void SetBunchSize(size_t value);
 
     void CloseFiles();
     void DeleteFiles();
@@ -187,9 +187,9 @@ class DataProcessor : private virtual slsDetectorDefs, public ThreadObject {
 
     File *dataFile_{nullptr};
 
-    uint32_t fifoBunchSize{0};
+    size_t fifoBunchSize{0};
     /** size in memory including headers */
-    uint32_t fifoBunchSizeBytes{0};
+    size_t fifoBunchSizeBytes{0};
 
     // call back
     /**
diff --git a/slsReceiverSoftware/src/DataStreamer.cpp b/slsReceiverSoftware/src/DataStreamer.cpp
index d0565d5f0..4f93ba77b 100644
--- a/slsReceiverSoftware/src/DataStreamer.cpp
+++ b/slsReceiverSoftware/src/DataStreamer.cpp
@@ -81,7 +81,7 @@ void DataStreamer::SetAdditionalJsonHeader(
     isAdditionalJsonUpdated = true;
 }
 
-void DataStreamer::SetBunchSize(uint32_t value) {
+void DataStreamer::SetBunchSize(size_t value) {
     fifoBunchSize = value;
 }
 
@@ -126,7 +126,7 @@ void DataStreamer::ThreadExecution() {
                    << std::hex << (void *)(buffer) << std::dec << ":" << buffer;
 
      char* tempBuffer = buffer;
-    for (uint32_t iFrame = 0; iFrame != fifoBunchSize; iFrame ++) {
+    for (size_t iFrame = 0; iFrame != fifoBunchSize; iFrame ++) {
 
         //  end of acquisition (check dummy)
         auto numBytes = *reinterpret_cast<uint32_t *>(tempBuffer);
diff --git a/slsReceiverSoftware/src/DataStreamer.h b/slsReceiverSoftware/src/DataStreamer.h
index bc38ac9f0..13eacf773 100644
--- a/slsReceiverSoftware/src/DataStreamer.h
+++ b/slsReceiverSoftware/src/DataStreamer.h
@@ -56,7 +56,7 @@ class DataStreamer : private virtual slsDetectorDefs, public ThreadObject {
     void SetFlipRows(bool fd);
     void
     SetAdditionalJsonHeader(const std::map<std::string, std::string> &json);
-    void SetBunchSize(uint32_t value);
+    void SetBunchSize(size_t value);
 
     /**
      * Creates Zmq Sockets
@@ -137,9 +137,9 @@ class DataStreamer : private virtual slsDetectorDefs, public ThreadObject {
     bool *quadEnable;
     uint64_t *totalNumFrames;
 
-    uint32_t fifoBunchSize{0};
+    size_t fifoBunchSize{0};
     /** size in memory including headers */
-    uint32_t fifoBunchSizeBytes{0};
+    size_t fifoBunchSizeBytes{0};
 };
 
 } // namespace sls
diff --git a/slsReceiverSoftware/src/Implementation.cpp b/slsReceiverSoftware/src/Implementation.cpp
index 69f37c378..bfb046322 100644
--- a/slsReceiverSoftware/src/Implementation.cpp
+++ b/slsReceiverSoftware/src/Implementation.cpp
@@ -455,9 +455,9 @@ void Implementation::setReceiverROIMetadata(const ROI arg) {
     LOG(logINFO) << "receiver roi Metadata: " << ToString(receiverRoiMetadata);
 }
 
-uint32_t Implementation::getBunchSize() const { return bunchSize; }
+size_t Implementation::getBunchSize() const { return bunchSize; }
 
-void Implementation::setBunchSize(const uint32_t i) {
+void Implementation::setBunchSize(const size_t i) {
     if (bunchSize != i) {
         bunchSize = i;
         for (const auto &it : listener)
diff --git a/slsReceiverSoftware/src/Implementation.h b/slsReceiverSoftware/src/Implementation.h
index 1c8708581..64ede98df 100644
--- a/slsReceiverSoftware/src/Implementation.h
+++ b/slsReceiverSoftware/src/Implementation.h
@@ -59,8 +59,8 @@ class Implementation : private virtual slsDetectorDefs {
     ROI getReceiverROI() const;
     void setReceiverROI(const ROI arg);
     void setReceiverROIMetadata(const ROI arg);
-    uint32_t getBunchSize() const;
-    void setBunchSize(const uint32_t i);
+    size_t getBunchSize() const;
+    void setBunchSize(const size_t i);
 
     /**************************************************
      *                                                 *
@@ -313,7 +313,7 @@ class Implementation : private virtual slsDetectorDefs {
     std::array<ROI, 2> portRois{};
     // receiver roi for complete detector for metadata
     ROI receiverRoiMetadata{};
-    uint32_t bunchSize{0};
+    size_t bunchSize{0};
 
     // file parameters
     fileFormat fileFormatType{BINARY};
diff --git a/slsReceiverSoftware/src/Listener.cpp b/slsReceiverSoftware/src/Listener.cpp
index 548492988..2e474b54b 100644
--- a/slsReceiverSoftware/src/Listener.cpp
+++ b/slsReceiverSoftware/src/Listener.cpp
@@ -126,7 +126,7 @@ void Listener::SetGeneralData(GeneralData *g) { generalData = g; }
 
 void Listener::SetActivate(bool enable) { activated = enable; }
 
-void Listener::SetBunchSize(uint32_t value) {
+void Listener::SetBunchSize(size_t value) {
     fifoBunchSize = value;
 }
 
@@ -232,47 +232,51 @@ void Listener::SetHardCodedPosition(uint16_t r, uint16_t c) {
 void Listener::ThreadExecution() {
     char *buffer;
     fifo->GetNewAddress(buffer);
-    LOG(logDEBUG5) << "Listener " << index
+    LOG(logDEBUG1) << "Listener " << index
                    << ", "
                       "pop 0x"
                    << std::hex << (void *)(buffer) << std::dec << ":" << buffer;
 
     // get data
     char* tempBuffer = buffer;
-    for (uint32_t iFrame = 0; iFrame != fifoBunchSize; iFrame ++) {
+    for (size_t iFrame = 0; iFrame != fifoBunchSize; iFrame ++) {
      
         // end of acquisition or not activated
         if ((*status == TRANSMITTING || !udpSocketAlive) && !carryOverFlag) {
             (*((uint32_t *)tempBuffer)) = DUMMY_PACKET_VALUE;
+            LOG(logDEBUG1) << iFrame << ": dummy=" << DUMMY_PACKET_VALUE;
             StopListening(buffer);
             return;
         }
-        LOG(logDEBUG) << "iframe:" << iFrame << " currentframeindex:" << currentFrameIndex;
+        LOG(logDEBUG1) << "iframe:" << iFrame << " currentframeindex:" << currentFrameIndex;
         int rc = ListenToAnImage(tempBuffer);
 
         // socket closed or discarding image (free retake)
             // weird frame numbers (print and rc = 0), then retake
         if (rc <= 0) {
             if (udpSocketAlive) {
+                LOG(logDEBUG1) << iFrame << ": rc<=0" << std::hex << static_cast<void *>(tempBuffer)  << std::dec;
                 --iFrame;
             }
         } else {
             (*((uint32_t *)tempBuffer)) = rc;
+            LOG(logDEBUG1) << iFrame << ": rc=" << rc <<  " addr:" << std::hex << static_cast<void *>(tempBuffer)  << std::dec;
             tempBuffer += fifoBunchSizeBytes;
         }
     }
 
     // last check
-    if ((*status != TRANSMITTING || !udpSocketAlive) && !carryOverFlag) {
+   /* if ((*status != TRANSMITTING || !udpSocketAlive) && !carryOverFlag) {
         LOG(logINFOBLUE) << "Last check " << std::hex << static_cast<void *>(tempBuffer)  << std::dec;
         (*((uint32_t *)tempBuffer)) = DUMMY_PACKET_VALUE;
+            LOG(logINFOBLUE) << ": dummy=" << DUMMY_PACKET_VALUE;
         StopListening(buffer);
         return;
-    }
+    }*/
 
     // push into fifo
     fifo->PushAddress(buffer);
-    LOG(logINFOBLUE) << "Pushed Listening bunch " << (void*)(buffer);
+    LOG(logDEBUG1) << "Pushed Listening bunch " << std::hex << static_cast<void *>(tempBuffer)  << std::dec;
 
     // Statistics
     if (!(*silentMode)) {
@@ -287,7 +291,7 @@ void Listener::ThreadExecution() {
 
 void Listener::StopListening(char *buf) {
     fifo->PushAddress(buf);
-    LOG(logINFOBLUE) << "Pushed Listening bunch (EOA) " << (void*)(buf);
+    LOG(logDEBUG1) << "Pushed Listening bunch (EOA) " << std::hex << static_cast<void *>(buf)  << std::dec;
     StopRunning();
     LOG(logDEBUG1) << index << ": Listening Packets (" << *udpPortNumber
                    << ") : " << numPacketsCaught;
diff --git a/slsReceiverSoftware/src/Listener.h b/slsReceiverSoftware/src/Listener.h
index 6f723f760..13404d190 100644
--- a/slsReceiverSoftware/src/Listener.h
+++ b/slsReceiverSoftware/src/Listener.h
@@ -65,7 +65,7 @@ class Listener : private virtual slsDetectorDefs, public ThreadObject {
     void ResetParametersforNewAcquisition();
     void SetGeneralData(GeneralData *g);
     void SetActivate(bool enable);
-    void SetBunchSize(uint32_t value);
+    void SetBunchSize(size_t value);
 
     void CreateUDPSockets();
     void ShutDownUDPSocket();
@@ -167,9 +167,9 @@ class Listener : private virtual slsDetectorDefs, public ThreadObject {
     std::unique_ptr<char[]> listeningPacket;
     std::atomic<bool> udpSocketAlive{false};
 
-    uint32_t fifoBunchSize{0};
+    size_t fifoBunchSize{0};
     /** size in memory including headers */
-    uint32_t fifoBunchSizeBytes{0};
+    size_t fifoBunchSizeBytes{0};
 
     // for print progress during acquisition*/
     uint32_t numPacketsStatistic{0};
diff --git a/slsReceiverSoftware/src/receiver_defs.h b/slsReceiverSoftware/src/receiver_defs.h
index e65623e90..81f024084 100644
--- a/slsReceiverSoftware/src/receiver_defs.h
+++ b/slsReceiverSoftware/src/receiver_defs.h
@@ -37,10 +37,8 @@ namespace sls {
 #define FILE_BUFFER_SIZE (16 * 1024 * 1024) // 16mb
 
 // fifo
-#define FIFO_HEADER_NUMBYTES   (8)
+#define FIFO_HEADER_NUMBYTES   (16)
 #define FIFO_DATASIZE_NUMBYTES (4)
-#define FIFO_PADDING_NUMBYTES                                                  \
-    (4) // for 8 byte alignment due to sls_receiver_header structure
 
 // hdf5
 #define MAX_CHUNKED_IMAGES (1)