diff --git a/sf-writer/src/ImageAssembler.cpp b/sf-writer/src/ImageAssembler.cpp
index 32515ac..3329c01 100644
--- a/sf-writer/src/ImageAssembler.cpp
+++ b/sf-writer/src/ImageAssembler.cpp
@@ -10,6 +10,11 @@ ImageAssembler::ImageAssembler(const size_t n_modules) :
 {
     image_buffer_ = new char[IA_N_SLOTS * image_buffer_slot_n_bytes_];
     metadata_buffer_ = new ImageMetadataBlock[IA_N_SLOTS];
+    buffer_status_ = new atomic_int[IA_N_SLOTS];
+
+    for (size_t i=0; i<IA_N_SLOTS; i++) {
+        buffer_status_[i] = 0;
+    }
 }
 
 ImageAssembler::~ImageAssembler()
@@ -28,6 +33,14 @@ void ImageAssembler::process(
         const int i_module,
         const BufferBinaryBlock* block_buffer)
 {
+    // TODO: Temp workaround. Make proper initialization.
+    if (i_module == 0) {
+        metadata_buffer_[slot_id].block_first_pulse_id =
+                block_buffer->frame[0].metadata.pulse_id;
+        metadata_buffer_[slot_id].block_last_pulse_id =
+                block_buffer->frame[BUFFER_BLOCK_SIZE-1].metadata.pulse_id;
+    }
+
     size_t slot_offset = slot_id * image_buffer_slot_n_bytes_;
     size_t module_image_offset = i_module * MODULE_N_BYTES;
 
@@ -39,7 +52,17 @@ void ImageAssembler::process(
             &(block_buffer->frame[i_pulse].data[0]),
             MODULE_N_BYTES);
 
-
+        // TODO: Temp workaround. We need to synchronize this access.
+        if (i_module == 0) {
+            metadata_buffer_[slot_id].pulse_id[i_pulse] =
+                    block_buffer->frame[i_pulse].metadata.pulse_id;
+            metadata_buffer_[slot_id].frame_index[i_pulse] =
+                    block_buffer->frame[i_pulse].metadata.frame_index;
+            metadata_buffer_[slot_id].daq_rec[i_pulse] =
+                    block_buffer->frame[i_pulse].metadata.daq_rec;
+//            metadata_buffer_[slot_id].is_good_image[i_pulse] =
+//                    block_buffer->frame[i_pulse].is_good_image.pulse_id;
+        }
     }
 }
 
@@ -50,7 +73,7 @@ int ImageAssembler::get_full_slot()
 
 void ImageAssembler::free_slot(const int slot_id)
 {
-
+    buffer_status_[slot_id] = n_modules_;
 }
 
 ImageMetadataBlock* ImageAssembler::get_metadata_buffer(const int slot_id)
diff --git a/sf-writer/src/ImageAssembler.hpp b/sf-writer/src/ImageAssembler.hpp
index a34cb59..10f7fdf 100644
--- a/sf-writer/src/ImageAssembler.hpp
+++ b/sf-writer/src/ImageAssembler.hpp
@@ -1,6 +1,8 @@
 #ifndef SF_DAQ_BUFFER_IMAGEASSEMBLER_HPP
 #define SF_DAQ_BUFFER_IMAGEASSEMBLER_HPP
 
+#include <atomic>
+
 #include "formats.hpp"
 
 const size_t IA_N_SLOTS = 2;
@@ -11,6 +13,7 @@ class ImageAssembler {
 
     char* image_buffer_;
     ImageMetadataBlock* metadata_buffer_;
+    std::atomic_int* buffer_status_;
 
 public:
     ImageAssembler(const size_t n_modules);