diff --git a/core-writer/include/RingBuffer.hpp b/core-writer/include/RingBuffer.hpp
index 38c9442..e4bf438 100644
--- a/core-writer/include/RingBuffer.hpp
+++ b/core-writer/include/RingBuffer.hpp
@@ -12,6 +12,21 @@
 #include <chrono>
 #include "date.h"
 
+struct FileBufferMetadata {
+    // Needed by RingBuffer
+    size_t buffer_slot_index;
+    const size_t frame_bytes_size = 2*512*1024*1000;
+
+    uint64_t start_pulse_id;
+    uint64_t stop_pulse_id;
+    uint16_t module_id;
+
+    uint64_t pulse_id[1000];
+    uint64_t frame_index[1000];
+    uint32_t daq_rec[1000];
+    uint16_t n_received_packets[1000];
+};
+
 struct FrameMetadata
 {
     // Ring buffer needed data.
diff --git a/core-writer/src/RingBuffer.cpp b/core-writer/src/RingBuffer.cpp
index 750cb54..71a254b 100644
--- a/core-writer/src/RingBuffer.cpp
+++ b/core-writer/src/RingBuffer.cpp
@@ -300,4 +300,5 @@ size_t RingBuffer<T>::get_slot_size()
 }
 
 template class RingBuffer<FrameMetadata>;
-template class RingBuffer<UdpFrameMetadata>;
\ No newline at end of file
+template class RingBuffer<UdpFrameMetadata>;
+template class RingBuffer<FileBufferMetadata>;
\ No newline at end of file