diff --git a/core-buffer/include/SFWriter.hpp b/core-buffer/include/SFWriter.hpp
index c570dd3..b8fd593 100644
--- a/core-buffer/include/SFWriter.hpp
+++ b/core-buffer/include/SFWriter.hpp
@@ -26,7 +26,7 @@ public:
             const size_t n_frames,
             const size_t n_modules);
     ~SFWriter();
-    void write(char* data, std::shared_ptr<DetectorFrame> metadata);
+    void write(std::shared_ptr<DetectorFrame> metadata, char* data);
     void close_file();
 };
 
diff --git a/core-buffer/src/SFWriter.cpp b/core-buffer/src/SFWriter.cpp
index 6ffc111..3c05c7f 100644
--- a/core-buffer/src/SFWriter.cpp
+++ b/core-buffer/src/SFWriter.cpp
@@ -70,7 +70,7 @@ void SFWriter::close_file()
     file_.close();
 }
 
-void SFWriter::write(char* data, std::shared_ptr<DetectorFrame> metadata) {
+void SFWriter::write(shared_ptr<DetectorFrame> metadata, char* data) {
     auto pulse_id = metadata->pulse_id;
     auto frame_index = metadata->frame_index;
     auto daq_rec = metadata->daq_rec;
diff --git a/core-buffer/test/test_SFWriter.cpp b/core-buffer/test/test_SFWriter.cpp
index 7c10d44..22b23d3 100644
--- a/core-buffer/test/test_SFWriter.cpp
+++ b/core-buffer/test/test_SFWriter.cpp
@@ -8,11 +8,21 @@ TEST(SFWriter, basic_interaction)
     size_t n_modules = 2;
     size_t n_frames = 5;
 
+    RingBuffer<DetectorFrame> ring_buffer(10);
+    ring_buffer.initialize(MODULE_N_BYTES*n_modules);
+
     auto data = make_unique<char[]>(n_modules*MODULE_N_BYTES);
     auto metadata = make_shared<DetectorFrame>();
+    metadata->frame_bytes_size = n_modules*MODULE_N_BYTES;
+
+    auto* rb_pointer = ring_buffer.reserve(metadata);
+    memcpy(rb_pointer, data.get(), n_modules*MODULE_N_BYTES);
+    ring_buffer.commit(metadata);
+
+    auto rb_data = ring_buffer.read();
 
     SFWriter writer("ignore.h5", n_frames, n_modules);
-    writer.write(data.get(), metadata);
+    writer.write(rb_data.first, rb_data.second);
     writer.close_file();
 
     // TODO: Write some test.